Add OpenCensus and gopsutil as dependency

vendor/github.com/StackExchange/wmi/LICENSE

@@ -0,0 +1,20 @@
+The MIT License (MIT)
+
+Copyright (c) 2013 Stack Exchange
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/StackExchange/wmi/README.md

@@ -0,0 +1,6 @@
+wmi
+===
+
+Package wmi provides a WQL interface to Windows WMI.
+
+Note: It interfaces with WMI on the local machine, therefore it only runs on Windows.

vendor/github.com/StackExchange/wmi/swbemservices.go

@@ -0,0 +1,260 @@
+// +build windows
+
+package wmi
+
+import (
+	"fmt"
+	"reflect"
+	"runtime"
+	"sync"
+
+	"github.com/go-ole/go-ole"
+	"github.com/go-ole/go-ole/oleutil"
+)
+
+// SWbemServices is used to access wmi. See https://msdn.microsoft.com/en-us/library/aa393719(v=vs.85).aspx
+type SWbemServices struct {
+	//TODO: track namespace. Not sure if we can re connect to a different namespace using the same instance
+	cWMIClient            *Client //This could also be an embedded struct, but then we would need to branch on Client vs SWbemServices in the Query method
+	sWbemLocatorIUnknown  *ole.IUnknown
+	sWbemLocatorIDispatch *ole.IDispatch
+	queries               chan *queryRequest
+	closeError            chan error
+	lQueryorClose         sync.Mutex
+}
+
+type queryRequest struct {
+	query    string
+	dst      interface{}
+	args     []interface{}
+	finished chan error
+}
+
+// InitializeSWbemServices will return a new SWbemServices object that can be used to query WMI
+func InitializeSWbemServices(c *Client, connectServerArgs ...interface{}) (*SWbemServices, error) {
+	//fmt.Println("InitializeSWbemServices: Starting")
+	//TODO: implement connectServerArgs as optional argument for init with connectServer call
+	s := new(SWbemServices)
+	s.cWMIClient = c
+	s.queries = make(chan *queryRequest)
+	initError := make(chan error)
+	go s.process(initError)
+
+	err, ok := <-initError
+	if ok {
+		return nil, err //Send error to caller
+	}
+	//fmt.Println("InitializeSWbemServices: Finished")
+	return s, nil
+}
+
+// Close will clear and release all of the SWbemServices resources
+func (s *SWbemServices) Close() error {
+	s.lQueryorClose.Lock()
+	if s == nil || s.sWbemLocatorIDispatch == nil {
+		s.lQueryorClose.Unlock()
+		return fmt.Errorf("SWbemServices is not Initialized")
+	}
+	if s.queries == nil {
+		s.lQueryorClose.Unlock()
+		return fmt.Errorf("SWbemServices has been closed")
+	}
+	//fmt.Println("Close: sending close request")
+	var result error
+	ce := make(chan error)
+	s.closeError = ce //Race condition if multiple callers to close. May need to lock here
+	close(s.queries)  //Tell background to shut things down
+	s.lQueryorClose.Unlock()
+	err, ok := <-ce
+	if ok {
+		result = err
+	}
+	//fmt.Println("Close: finished")
+	return result
+}
+
+func (s *SWbemServices) process(initError chan error) {
+	//fmt.Println("process: starting background thread initialization")
+	//All OLE/WMI calls must happen on the same initialized thead, so lock this goroutine
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	err := ole.CoInitializeEx(0, ole.COINIT_MULTITHREADED)
+	if err != nil {
+		oleCode := err.(*ole.OleError).Code()
+		if oleCode != ole.S_OK && oleCode != S_FALSE {
+			initError <- fmt.Errorf("ole.CoInitializeEx error: %v", err)
+			return
+		}
+	}
+	defer ole.CoUninitialize()
+
+	unknown, err := oleutil.CreateObject("WbemScripting.SWbemLocator")
+	if err != nil {
+		initError <- fmt.Errorf("CreateObject SWbemLocator error: %v", err)
+		return
+	} else if unknown == nil {
+		initError <- ErrNilCreateObject
+		return
+	}
+	defer unknown.Release()
+	s.sWbemLocatorIUnknown = unknown
+
+	dispatch, err := s.sWbemLocatorIUnknown.QueryInterface(ole.IID_IDispatch)
+	if err != nil {
+		initError <- fmt.Errorf("SWbemLocator QueryInterface error: %v", err)
+		return
+	}
+	defer dispatch.Release()
+	s.sWbemLocatorIDispatch = dispatch
+
+	// we can't do the ConnectServer call outside the loop unless we find a way to track and re-init the connectServerArgs
+	//fmt.Println("process: initialized. closing initError")
+	close(initError)
+	//fmt.Println("process: waiting for queries")
+	for q := range s.queries {
+		//fmt.Printf("process: new query: len(query)=%d\n", len(q.query))
+		errQuery := s.queryBackground(q)
+		//fmt.Println("process: s.queryBackground finished")
+		if errQuery != nil {
+			q.finished <- errQuery
+		}
+		close(q.finished)
+	}
+	//fmt.Println("process: queries channel closed")
+	s.queries = nil //set channel to nil so we know it is closed
+	//TODO: I think the Release/Clear calls can panic if things are in a bad state.
+	//TODO: May need to recover from panics and send error to method caller instead.
+	close(s.closeError)
+}
+
+// Query runs the WQL query using a SWbemServices instance and appends the values to dst.
+//
+// dst must have type *[]S or *[]*S, for some struct type S. Fields selected in
+// the query must have the same name in dst. Supported types are all signed and
+// unsigned integers, time.Time, string, bool, or a pointer to one of those.
+// Array types are not supported.
+//
+// By default, the local machine and default namespace are used. These can be
+// changed using connectServerArgs. See
+// http://msdn.microsoft.com/en-us/library/aa393720.aspx for details.
+func (s *SWbemServices) Query(query string, dst interface{}, connectServerArgs ...interface{}) error {
+	s.lQueryorClose.Lock()
+	if s == nil || s.sWbemLocatorIDispatch == nil {
+		s.lQueryorClose.Unlock()
+		return fmt.Errorf("SWbemServices is not Initialized")
+	}
+	if s.queries == nil {
+		s.lQueryorClose.Unlock()
+		return fmt.Errorf("SWbemServices has been closed")
+	}
+
+	//fmt.Println("Query: Sending query request")
+	qr := queryRequest{
+		query:    query,
+		dst:      dst,
+		args:     connectServerArgs,
+		finished: make(chan error),
+	}
+	s.queries <- &qr
+	s.lQueryorClose.Unlock()
+	err, ok := <-qr.finished
+	if ok {
+		//fmt.Println("Query: Finished with error")
+		return err //Send error to caller
+	}
+	//fmt.Println("Query: Finished")
+	return nil
+}
+
+func (s *SWbemServices) queryBackground(q *queryRequest) error {
+	if s == nil || s.sWbemLocatorIDispatch == nil {
+		return fmt.Errorf("SWbemServices is not Initialized")
+	}
+	wmi := s.sWbemLocatorIDispatch //Should just rename in the code, but this will help as we break things apart
+	//fmt.Println("queryBackground: Starting")
+
+	dv := reflect.ValueOf(q.dst)
+	if dv.Kind() != reflect.Ptr || dv.IsNil() {
+		return ErrInvalidEntityType
+	}
+	dv = dv.Elem()
+	mat, elemType := checkMultiArg(dv)
+	if mat == multiArgTypeInvalid {
+		return ErrInvalidEntityType
+	}
+
+	// service is a SWbemServices
+	serviceRaw, err := oleutil.CallMethod(wmi, "ConnectServer", q.args...)
+	if err != nil {
+		return err
+	}
+	service := serviceRaw.ToIDispatch()
+	defer serviceRaw.Clear()
+
+	// result is a SWBemObjectSet
+	resultRaw, err := oleutil.CallMethod(service, "ExecQuery", q.query)
+	if err != nil {
+		return err
+	}
+	result := resultRaw.ToIDispatch()
+	defer resultRaw.Clear()
+
+	count, err := oleInt64(result, "Count")
+	if err != nil {
+		return err
+	}
+
+	enumProperty, err := result.GetProperty("_NewEnum")
+	if err != nil {
+		return err
+	}
+	defer enumProperty.Clear()
+
+	enum, err := enumProperty.ToIUnknown().IEnumVARIANT(ole.IID_IEnumVariant)
+	if err != nil {
+		return err
+	}
+	if enum == nil {
+		return fmt.Errorf("can't get IEnumVARIANT, enum is nil")
+	}
+	defer enum.Release()
+
+	// Initialize a slice with Count capacity
+	dv.Set(reflect.MakeSlice(dv.Type(), 0, int(count)))
+
+	var errFieldMismatch error
+	for itemRaw, length, err := enum.Next(1); length > 0; itemRaw, length, err = enum.Next(1) {
+		if err != nil {
+			return err
+		}
+
+		err := func() error {
+			// item is a SWbemObject, but really a Win32_Process
+			item := itemRaw.ToIDispatch()
+			defer item.Release()
+
+			ev := reflect.New(elemType)
+			if err = s.cWMIClient.loadEntity(ev.Interface(), item); err != nil {
+				if _, ok := err.(*ErrFieldMismatch); ok {
+					// We continue loading entities even in the face of field mismatch errors.
+					// If we encounter any other error, that other error is returned. Otherwise,
+					// an ErrFieldMismatch is returned.
+					errFieldMismatch = err
+				} else {
+					return err
+				}
+			}
+			if mat != multiArgTypeStructPtr {
+				ev = ev.Elem()
+			}
+			dv.Set(reflect.Append(dv, ev))
+			return nil
+		}()
+		if err != nil {
+			return err
+		}
+	}
+	//fmt.Println("queryBackground: Finished")
+	return errFieldMismatch
+}

vendor/github.com/StackExchange/wmi/wmi.go

@@ -0,0 +1,490 @@
+// +build windows
+
+/*
+Package wmi provides a WQL interface for WMI on Windows.
+
+Example code to print names of running processes:
+
+	type Win32_Process struct {
+		Name string
+	}
+
+	func main() {
+		var dst []Win32_Process
+		q := wmi.CreateQuery(&dst, "")
+		err := wmi.Query(q, &dst)
+		if err != nil {
+			log.Fatal(err)
+		}
+		for i, v := range dst {
+			println(i, v.Name)
+		}
+	}
+
+*/
+package wmi
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+	"runtime"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-ole/go-ole"
+	"github.com/go-ole/go-ole/oleutil"
+)
+
+var l = log.New(os.Stdout, "", log.LstdFlags)
+
+var (
+	ErrInvalidEntityType = errors.New("wmi: invalid entity type")
+	// ErrNilCreateObject is the error returned if CreateObject returns nil even
+	// if the error was nil.
+	ErrNilCreateObject = errors.New("wmi: create object returned nil")
+	lock               sync.Mutex
+)
+
+// S_FALSE is returned by CoInitializeEx if it was already called on this thread.
+const S_FALSE = 0x00000001
+
+// QueryNamespace invokes Query with the given namespace on the local machine.
+func QueryNamespace(query string, dst interface{}, namespace string) error {
+	return Query(query, dst, nil, namespace)
+}
+
+// Query runs the WQL query and appends the values to dst.
+//
+// dst must have type *[]S or *[]*S, for some struct type S. Fields selected in
+// the query must have the same name in dst. Supported types are all signed and
+// unsigned integers, time.Time, string, bool, or a pointer to one of those.
+// Array types are not supported.
+//
+// By default, the local machine and default namespace are used. These can be
+// changed using connectServerArgs. See
+// http://msdn.microsoft.com/en-us/library/aa393720.aspx for details.
+//
+// Query is a wrapper around DefaultClient.Query.
+func Query(query string, dst interface{}, connectServerArgs ...interface{}) error {
+	if DefaultClient.SWbemServicesClient == nil {
+		return DefaultClient.Query(query, dst, connectServerArgs...)
+	}
+	return DefaultClient.SWbemServicesClient.Query(query, dst, connectServerArgs...)
+}
+
+// A Client is an WMI query client.
+//
+// Its zero value (DefaultClient) is a usable client.
+type Client struct {
+	// NonePtrZero specifies if nil values for fields which aren't pointers
+	// should be returned as the field types zero value.
+	//
+	// Setting this to true allows stucts without pointer fields to be used
+	// without the risk failure should a nil value returned from WMI.
+	NonePtrZero bool
+
+	// PtrNil specifies if nil values for pointer fields should be returned
+	// as nil.
+	//
+	// Setting this to true will set pointer fields to nil where WMI
+	// returned nil, otherwise the types zero value will be returned.
+	PtrNil bool
+
+	// AllowMissingFields specifies that struct fields not present in the
+	// query result should not result in an error.
+	//
+	// Setting this to true allows custom queries to be used with full
+	// struct definitions instead of having to define multiple structs.
+	AllowMissingFields bool
+
+	// SWbemServiceClient is an optional SWbemServices object that can be
+	// initialized and then reused across multiple queries. If it is null
+	// then the method will initialize a new temporary client each time.
+	SWbemServicesClient *SWbemServices
+}
+
+// DefaultClient is the default Client and is used by Query, QueryNamespace
+var DefaultClient = &Client{}
+
+// Query runs the WQL query and appends the values to dst.
+//
+// dst must have type *[]S or *[]*S, for some struct type S. Fields selected in
+// the query must have the same name in dst. Supported types are all signed and
+// unsigned integers, time.Time, string, bool, or a pointer to one of those.
+// Array types are not supported.
+//
+// By default, the local machine and default namespace are used. These can be
+// changed using connectServerArgs. See
+// http://msdn.microsoft.com/en-us/library/aa393720.aspx for details.
+func (c *Client) Query(query string, dst interface{}, connectServerArgs ...interface{}) error {
+	dv := reflect.ValueOf(dst)
+	if dv.Kind() != reflect.Ptr || dv.IsNil() {
+		return ErrInvalidEntityType
+	}
+	dv = dv.Elem()
+	mat, elemType := checkMultiArg(dv)
+	if mat == multiArgTypeInvalid {
+		return ErrInvalidEntityType
+	}
+
+	lock.Lock()
+	defer lock.Unlock()
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	err := ole.CoInitializeEx(0, ole.COINIT_MULTITHREADED)
+	if err != nil {
+		oleCode := err.(*ole.OleError).Code()
+		if oleCode != ole.S_OK && oleCode != S_FALSE {
+			return err
+		}
+	}
+	defer ole.CoUninitialize()
+
+	unknown, err := oleutil.CreateObject("WbemScripting.SWbemLocator")
+	if err != nil {
+		return err
+	} else if unknown == nil {
+		return ErrNilCreateObject
+	}
+	defer unknown.Release()
+
+	wmi, err := unknown.QueryInterface(ole.IID_IDispatch)
+	if err != nil {
+		return err
+	}
+	defer wmi.Release()
+
+	// service is a SWbemServices
+	serviceRaw, err := oleutil.CallMethod(wmi, "ConnectServer", connectServerArgs...)
+	if err != nil {
+		return err
+	}
+	service := serviceRaw.ToIDispatch()
+	defer serviceRaw.Clear()
+
+	// result is a SWBemObjectSet
+	resultRaw, err := oleutil.CallMethod(service, "ExecQuery", query)
+	if err != nil {
+		return err
+	}
+	result := resultRaw.ToIDispatch()
+	defer resultRaw.Clear()
+
+	count, err := oleInt64(result, "Count")
+	if err != nil {
+		return err
+	}
+
+	enumProperty, err := result.GetProperty("_NewEnum")
+	if err != nil {
+		return err
+	}
+	defer enumProperty.Clear()
+
+	enum, err := enumProperty.ToIUnknown().IEnumVARIANT(ole.IID_IEnumVariant)
+	if err != nil {
+		return err
+	}
+	if enum == nil {
+		return fmt.Errorf("can't get IEnumVARIANT, enum is nil")
+	}
+	defer enum.Release()
+
+	// Initialize a slice with Count capacity
+	dv.Set(reflect.MakeSlice(dv.Type(), 0, int(count)))
+
+	var errFieldMismatch error
+	for itemRaw, length, err := enum.Next(1); length > 0; itemRaw, length, err = enum.Next(1) {
+		if err != nil {
+			return err
+		}
+
+		err := func() error {
+			// item is a SWbemObject, but really a Win32_Process
+			item := itemRaw.ToIDispatch()
+			defer item.Release()
+
+			ev := reflect.New(elemType)
+			if err = c.loadEntity(ev.Interface(), item); err != nil {
+				if _, ok := err.(*ErrFieldMismatch); ok {
+					// We continue loading entities even in the face of field mismatch errors.
+					// If we encounter any other error, that other error is returned. Otherwise,
+					// an ErrFieldMismatch is returned.
+					errFieldMismatch = err
+				} else {
+					return err
+				}
+			}
+			if mat != multiArgTypeStructPtr {
+				ev = ev.Elem()
+			}
+			dv.Set(reflect.Append(dv, ev))
+			return nil
+		}()
+		if err != nil {
+			return err
+		}
+	}
+	return errFieldMismatch
+}
+
+// ErrFieldMismatch is returned when a field is to be loaded into a different
+// type than the one it was stored from, or when a field is missing or
+// unexported in the destination struct.
+// StructType is the type of the struct pointed to by the destination argument.
+type ErrFieldMismatch struct {
+	StructType reflect.Type
+	FieldName  string
+	Reason     string
+}
+
+func (e *ErrFieldMismatch) Error() string {
+	return fmt.Sprintf("wmi: cannot load field %q into a %q: %s",
+		e.FieldName, e.StructType, e.Reason)
+}
+
+var timeType = reflect.TypeOf(time.Time{})
+
+// loadEntity loads a SWbemObject into a struct pointer.
+func (c *Client) loadEntity(dst interface{}, src *ole.IDispatch) (errFieldMismatch error) {
+	v := reflect.ValueOf(dst).Elem()
+	for i := 0; i < v.NumField(); i++ {
+		f := v.Field(i)
+		of := f
+		isPtr := f.Kind() == reflect.Ptr
+		if isPtr {
+			ptr := reflect.New(f.Type().Elem())
+			f.Set(ptr)
+			f = f.Elem()
+		}
+		n := v.Type().Field(i).Name
+		if !f.CanSet() {
+			return &ErrFieldMismatch{
+				StructType: of.Type(),
+				FieldName:  n,
+				Reason:     "CanSet() is false",
+			}
+		}
+		prop, err := oleutil.GetProperty(src, n)
+		if err != nil {
+			if !c.AllowMissingFields {
+				errFieldMismatch = &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     "no such struct field",
+				}
+			}
+			continue
+		}
+		defer prop.Clear()
+
+		if prop.VT == 0x1 { //VT_NULL
+			continue
+		}
+
+		switch val := prop.Value().(type) {
+		case int8, int16, int32, int64, int:
+			v := reflect.ValueOf(val).Int()
+			switch f.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+				f.SetInt(v)
+			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+				f.SetUint(uint64(v))
+			default:
+				return &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     "not an integer class",
+				}
+			}
+		case uint8, uint16, uint32, uint64:
+			v := reflect.ValueOf(val).Uint()
+			switch f.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+				f.SetInt(int64(v))
+			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+				f.SetUint(v)
+			default:
+				return &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     "not an integer class",
+				}
+			}
+		case string:
+			switch f.Kind() {
+			case reflect.String:
+				f.SetString(val)
+			case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+				iv, err := strconv.ParseInt(val, 10, 64)
+				if err != nil {
+					return err
+				}
+				f.SetInt(iv)
+			case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+				uv, err := strconv.ParseUint(val, 10, 64)
+				if err != nil {
+					return err
+				}
+				f.SetUint(uv)
+			case reflect.Struct:
+				switch f.Type() {
+				case timeType:
+					if len(val) == 25 {
+						mins, err := strconv.Atoi(val[22:])
+						if err != nil {
+							return err
+						}
+						val = val[:22] + fmt.Sprintf("%02d%02d", mins/60, mins%60)
+					}
+					t, err := time.Parse("20060102150405.000000-0700", val)
+					if err != nil {
+						return err
+					}
+					f.Set(reflect.ValueOf(t))
+				}
+			}
+		case bool:
+			switch f.Kind() {
+			case reflect.Bool:
+				f.SetBool(val)
+			default:
+				return &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     "not a bool",
+				}
+			}
+		case float32:
+			switch f.Kind() {
+			case reflect.Float32:
+				f.SetFloat(float64(val))
+			default:
+				return &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     "not a Float32",
+				}
+			}
+		default:
+			if f.Kind() == reflect.Slice {
+				switch f.Type().Elem().Kind() {
+				case reflect.String:
+					safeArray := prop.ToArray()
+					if safeArray != nil {
+						arr := safeArray.ToValueArray()
+						fArr := reflect.MakeSlice(f.Type(), len(arr), len(arr))
+						for i, v := range arr {
+							s := fArr.Index(i)
+							s.SetString(v.(string))
+						}
+						f.Set(fArr)
+					}
+				case reflect.Uint8:
+					safeArray := prop.ToArray()
+					if safeArray != nil {
+						arr := safeArray.ToValueArray()
+						fArr := reflect.MakeSlice(f.Type(), len(arr), len(arr))
+						for i, v := range arr {
+							s := fArr.Index(i)
+							s.SetUint(reflect.ValueOf(v).Uint())
+						}
+						f.Set(fArr)
+					}
+				default:
+					return &ErrFieldMismatch{
+						StructType: of.Type(),
+						FieldName:  n,
+						Reason:     fmt.Sprintf("unsupported slice type (%T)", val),
+					}
+				}
+			} else {
+				typeof := reflect.TypeOf(val)
+				if typeof == nil && (isPtr || c.NonePtrZero) {
+					if (isPtr && c.PtrNil) || (!isPtr && c.NonePtrZero) {
+						of.Set(reflect.Zero(of.Type()))
+					}
+					break
+				}
+				return &ErrFieldMismatch{
+					StructType: of.Type(),
+					FieldName:  n,
+					Reason:     fmt.Sprintf("unsupported type (%T)", val),
+				}
+			}
+		}
+	}
+	return errFieldMismatch
+}
+
+type multiArgType int
+
+const (
+	multiArgTypeInvalid multiArgType = iota
+	multiArgTypeStruct
+	multiArgTypeStructPtr
+)
+
+// checkMultiArg checks that v has type []S, []*S for some struct type S.
+//
+// It returns what category the slice's elements are, and the reflect.Type
+// that represents S.
+func checkMultiArg(v reflect.Value) (m multiArgType, elemType reflect.Type) {
+	if v.Kind() != reflect.Slice {
+		return multiArgTypeInvalid, nil
+	}
+	elemType = v.Type().Elem()
+	switch elemType.Kind() {
+	case reflect.Struct:
+		return multiArgTypeStruct, elemType
+	case reflect.Ptr:
+		elemType = elemType.Elem()
+		if elemType.Kind() == reflect.Struct {
+			return multiArgTypeStructPtr, elemType
+		}
+	}
+	return multiArgTypeInvalid, nil
+}
+
+func oleInt64(item *ole.IDispatch, prop string) (int64, error) {
+	v, err := oleutil.GetProperty(item, prop)
+	if err != nil {
+		return 0, err
+	}
+	defer v.Clear()
+
+	i := int64(v.Val)
+	return i, nil
+}
+
+// CreateQuery returns a WQL query string that queries all columns of src. where
+// is an optional string that is appended to the query, to be used with WHERE
+// clauses. In such a case, the "WHERE" string should appear at the beginning.
+func CreateQuery(src interface{}, where string) string {
+	var b bytes.Buffer
+	b.WriteString("SELECT ")
+	s := reflect.Indirect(reflect.ValueOf(src))
+	t := s.Type()
+	if s.Kind() == reflect.Slice {
+		t = t.Elem()
+	}
+	if t.Kind() != reflect.Struct {
+		return ""
+	}
+	var fields []string
+	for i := 0; i < t.NumField(); i++ {
+		fields = append(fields, t.Field(i).Name)
+	}
+	b.WriteString(strings.Join(fields, ", "))
+	b.WriteString(" FROM ")
+	b.WriteString(t.Name())
+	b.WriteString(" " + where)
+	return b.String()
+}

vendor/github.com/beorn7/perks/LICENSE

@@ -0,0 +1,20 @@
+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/beorn7/perks/quantile/stream.go

@@ -0,0 +1,316 @@
+// Package quantile computes approximate quantiles over an unbounded data
+// stream within low memory and CPU bounds.
+//
+// A small amount of accuracy is traded to achieve the above properties.
+//
+// Multiple streams can be merged before calling Query to generate a single set
+// of results. This is meaningful when the streams represent the same type of
+// data. See Merge and Samples.
+//
+// For more detailed information about the algorithm used, see:
+//
+// Effective Computation of Biased Quantiles over Data Streams
+//
+// http://www.cs.rutgers.edu/~muthu/bquant.pdf
+package quantile
+
+import (
+	"math"
+	"sort"
+)
+
+// Sample holds an observed value and meta information for compression. JSON
+// tags have been added for convenience.
+type Sample struct {
+	Value float64 `json:",string"`
+	Width float64 `json:",string"`
+	Delta float64 `json:",string"`
+}
+
+// Samples represents a slice of samples. It implements sort.Interface.
+type Samples []Sample
+
+func (a Samples) Len() int           { return len(a) }
+func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
+func (a Samples) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+type invariant func(s *stream, r float64) float64
+
+// NewLowBiased returns an initialized Stream for low-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the lower ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewLowBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * r
+	}
+	return newStream(ƒ)
+}
+
+// NewHighBiased returns an initialized Stream for high-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the higher ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewHighBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * (s.n - r)
+	}
+	return newStream(ƒ)
+}
+
+// NewTargeted returns an initialized Stream concerned with a particular set of
+// quantile values that are supplied a priori. Knowing these a priori reduces
+// space and computation time. The targets map maps the desired quantiles to
+// their absolute errors, i.e. the true quantile of a value returned by a query
+// is guaranteed to be within (Quantile±Epsilon).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
+func NewTargeted(targetMap map[float64]float64) *Stream {
+	// Convert map to slice to avoid slow iterations on a map.
+	// ƒ is called on the hot path, so converting the map to a slice
+	// beforehand results in significant CPU savings.
+	targets := targetMapToSlice(targetMap)
+
+	ƒ := func(s *stream, r float64) float64 {
+		var m = math.MaxFloat64
+		var f float64
+		for _, t := range targets {
+			if t.quantile*s.n <= r {
+				f = (2 * t.epsilon * r) / t.quantile
+			} else {
+				f = (2 * t.epsilon * (s.n - r)) / (1 - t.quantile)
+			}
+			if f < m {
+				m = f
+			}
+		}
+		return m
+	}
+	return newStream(ƒ)
+}
+
+type target struct {
+	quantile float64
+	epsilon  float64
+}
+
+func targetMapToSlice(targetMap map[float64]float64) []target {
+	targets := make([]target, 0, len(targetMap))
+
+	for quantile, epsilon := range targetMap {
+		t := target{
+			quantile: quantile,
+			epsilon:  epsilon,
+		}
+		targets = append(targets, t)
+	}
+
+	return targets
+}
+
+// Stream computes quantiles for a stream of float64s. It is not thread-safe by
+// design. Take care when using across multiple goroutines.
+type Stream struct {
+	*stream
+	b      Samples
+	sorted bool
+}
+
+func newStream(ƒ invariant) *Stream {
+	x := &stream{ƒ: ƒ}
+	return &Stream{x, make(Samples, 0, 500), true}
+}
+
+// Insert inserts v into the stream.
+func (s *Stream) Insert(v float64) {
+	s.insert(Sample{Value: v, Width: 1})
+}
+
+func (s *Stream) insert(sample Sample) {
+	s.b = append(s.b, sample)
+	s.sorted = false
+	if len(s.b) == cap(s.b) {
+		s.flush()
+	}
+}
+
+// Query returns the computed qth percentiles value. If s was created with
+// NewTargeted, and q is not in the set of quantiles provided a priori, Query
+// will return an unspecified result.
+func (s *Stream) Query(q float64) float64 {
+	if !s.flushed() {
+		// Fast path when there hasn't been enough data for a flush;
+		// this also yields better accuracy for small sets of data.
+		l := len(s.b)
+		if l == 0 {
+			return 0
+		}
+		i := int(math.Ceil(float64(l) * q))
+		if i > 0 {
+			i -= 1
+		}
+		s.maybeSort()
+		return s.b[i].Value
+	}
+	s.flush()
+	return s.stream.query(q)
+}
+
+// Merge merges samples into the underlying streams samples. This is handy when
+// merging multiple streams from separate threads, database shards, etc.
+//
+// ATTENTION: This method is broken and does not yield correct results. The
+// underlying algorithm is not capable of merging streams correctly.
+func (s *Stream) Merge(samples Samples) {
+	sort.Sort(samples)
+	s.stream.merge(samples)
+}
+
+// Reset reinitializes and clears the list reusing the samples buffer memory.
+func (s *Stream) Reset() {
+	s.stream.reset()
+	s.b = s.b[:0]
+}
+
+// Samples returns stream samples held by s.
+func (s *Stream) Samples() Samples {
+	if !s.flushed() {
+		return s.b
+	}
+	s.flush()
+	return s.stream.samples()
+}
+
+// Count returns the total number of samples observed in the stream
+// since initialization.
+func (s *Stream) Count() int {
+	return len(s.b) + s.stream.count()
+}
+
+func (s *Stream) flush() {
+	s.maybeSort()
+	s.stream.merge(s.b)
+	s.b = s.b[:0]
+}
+
+func (s *Stream) maybeSort() {
+	if !s.sorted {
+		s.sorted = true
+		sort.Sort(s.b)
+	}
+}
+
+func (s *Stream) flushed() bool {
+	return len(s.stream.l) > 0
+}
+
+type stream struct {
+	n float64
+	l []Sample
+	ƒ invariant
+}
+
+func (s *stream) reset() {
+	s.l = s.l[:0]
+	s.n = 0
+}
+
+func (s *stream) insert(v float64) {
+	s.merge(Samples{{v, 1, 0}})
+}
+
+func (s *stream) merge(samples Samples) {
+	// TODO(beorn7): This tries to merge not only individual samples, but
+	// whole summaries. The paper doesn't mention merging summaries at
+	// all. Unittests show that the merging is inaccurate. Find out how to
+	// do merges properly.
+	var r float64
+	i := 0
+	for _, sample := range samples {
+		for ; i < len(s.l); i++ {
+			c := s.l[i]
+			if c.Value > sample.Value {
+				// Insert at position i.
+				s.l = append(s.l, Sample{})
+				copy(s.l[i+1:], s.l[i:])
+				s.l[i] = Sample{
+					sample.Value,
+					sample.Width,
+					math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
+					// TODO(beorn7): How to calculate delta correctly?
+				}
+				i++
+				goto inserted
+			}
+			r += c.Width
+		}
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
+		i++
+	inserted:
+		s.n += sample.Width
+		r += sample.Width
+	}
+	s.compress()
+}
+
+func (s *stream) count() int {
+	return int(s.n)
+}
+
+func (s *stream) query(q float64) float64 {
+	t := math.Ceil(q * s.n)
+	t += math.Ceil(s.ƒ(s, t) / 2)
+	p := s.l[0]
+	var r float64
+	for _, c := range s.l[1:] {
+		r += p.Width
+		if r+c.Width+c.Delta > t {
+			return p.Value
+		}
+		p = c
+	}
+	return p.Value
+}
+
+func (s *stream) compress() {
+	if len(s.l) < 2 {
+		return
+	}
+	x := s.l[len(s.l)-1]
+	xi := len(s.l) - 1
+	r := s.n - 1 - x.Width
+
+	for i := len(s.l) - 2; i >= 0; i-- {
+		c := s.l[i]
+		if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
+			x.Width += c.Width
+			s.l[xi] = x
+			// Remove element at i.
+			copy(s.l[i:], s.l[i+1:])
+			s.l = s.l[:len(s.l)-1]
+			xi -= 1
+		} else {
+			x = c
+			xi = i
+		}
+		r -= c.Width
+	}
+}
+
+func (s *stream) samples() Samples {
+	samples := make(Samples, len(s.l))
+	copy(samples, s.l)
+	return samples
+}

vendor/github.com/go-ole/go-ole/.travis.yml

@@ -0,0 +1,8 @@
+language: go
+sudo: false
+
+go:
+  - 1.9.x
+  - 1.10.x
+  - 1.11.x
+  - tip

vendor/github.com/go-ole/go-ole/ChangeLog.md

@@ -0,0 +1,49 @@
+# Version 1.x.x
+
+* **Add more test cases and reference new test COM server project.** (Placeholder for future additions)
+
+# Version 1.2.0-alphaX
+
+**Minimum supported version is now Go 1.4. Go 1.1 support is deprecated, but should still build.**
+
+ * Added CI configuration for Travis-CI and AppVeyor.
+ * Added test InterfaceID and ClassID for the COM Test Server project.
+ * Added more inline documentation (#83).
+ * Added IEnumVARIANT implementation (#88).
+ * Added IEnumVARIANT test cases (#99, #100, #101).
+ * Added support for retrieving `time.Time` from VARIANT (#92).
+ * Added test case for IUnknown (#64).
+ * Added test case for IDispatch (#64).
+ * Added test cases for scalar variants (#64, #76).
+
+# Version 1.1.1
+
+ * Fixes for Linux build.
+ * Fixes for Windows build.
+
+# Version 1.1.0
+
+The change to provide building on all platforms is a new feature. The increase in minor version reflects that and allows those who wish to stay on 1.0.x to continue to do so. Support for 1.0.x will be limited to bug fixes.
+
+ * Move GUID out of variables.go into its own file to make new documentation available.
+ * Move OleError out of ole.go into its own file to make new documentation available.
+ * Add documentation to utility functions.
+ * Add documentation to variant receiver functions.
+ * Add documentation to ole structures.
+ * Make variant available to other systems outside of Windows.
+ * Make OLE structures available to other systems outside of Windows.
+
+## New Features
+
+ * Library should now be built on all platforms supported by Go. Library will NOOP on any platform that is not Windows.
+ * More functions are now documented and available on godoc.org.
+
+# Version 1.0.1
+
+ 1. Fix package references from repository location change.
+
+# Version 1.0.0
+
+This version is stable enough for use. The COM API is still incomplete, but provides enough functionality for accessing COM servers using IDispatch interface.
+
+There is no changelog for this version. Check commits for history.

vendor/github.com/go-ole/go-ole/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright © 2013-2017 Yasuhiro Matsumoto, <mattn.jp@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the “Software”), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/go-ole/go-ole/README.md

@@ -0,0 +1,46 @@
+# Go OLE
+
+[![Build status](https://ci.appveyor.com/api/projects/status/qr0u2sf7q43us9fj?svg=true)](https://ci.appveyor.com/project/jacobsantos/go-ole-jgs28)
+[![Build Status](https://travis-ci.org/go-ole/go-ole.svg?branch=master)](https://travis-ci.org/go-ole/go-ole)
+[![GoDoc](https://godoc.org/github.com/go-ole/go-ole?status.svg)](https://godoc.org/github.com/go-ole/go-ole)
+
+Go bindings for Windows COM using shared libraries instead of cgo.
+
+By Yasuhiro Matsumoto.
+
+## Install
+
+To experiment with go-ole, you can just compile and run the example program:
+
+```
+go get github.com/go-ole/go-ole
+cd /path/to/go-ole/
+go test
+
+cd /path/to/go-ole/example/excel
+go run excel.go
+```
+
+## Continuous Integration
+
+Continuous integration configuration has been added for both Travis-CI and AppVeyor. You will have to add these to your own account for your fork in order for it to run.
+
+**Travis-CI**
+
+Travis-CI was added to check builds on Linux to ensure that `go get` works when cross building. Currently, Travis-CI is not used to test cross-building, but this may be changed in the future. It is also not currently possible to test the library on Linux, since COM API is specific to Windows and it is not currently possible to run a COM server on Linux or even connect to a remote COM server.
+
+**AppVeyor**
+
+AppVeyor is used to build on Windows using the (in-development) test COM server. It is currently only used to test the build and ensure that the code works on Windows. It will be used to register a COM server and then run the test cases based on the test COM server.
+
+The tests currently do run and do pass and this should be maintained with commits.
+
+## Versioning
+
+Go OLE uses [semantic versioning](http://semver.org) for version numbers, which is similar to the version contract of the Go language. Which means that the major version will always maintain backwards compatibility with minor versions. Minor versions will only add new additions and changes. Fixes will always be in patch. 
+
+This contract should allow you to upgrade to new minor and patch versions without breakage or modifications to your existing code. Leave a ticket, if there is breakage, so that it could be fixed.
+
+## LICENSE
+
+Under the MIT License: http://mattn.mit-license.org/2013

vendor/github.com/go-ole/go-ole/appveyor.yml

@@ -0,0 +1,54 @@
+# Notes:
+#   - Minimal appveyor.yml file is an empty file. All sections are optional.
+#   - Indent each level of configuration with 2 spaces. Do not use tabs!
+#   - All section names are case-sensitive.
+#   - Section names should be unique on each level.
+
+version: "1.3.0.{build}-alpha-{branch}"
+
+os: Windows Server 2012 R2
+
+branches:
+  only:
+    - master
+    - v1.2
+    - v1.1
+    - v1.0
+
+skip_tags: true
+
+clone_folder: c:\gopath\src\github.com\go-ole\go-ole
+
+environment:
+  GOPATH: c:\gopath
+  matrix:
+  - GOARCH: amd64
+    GOVERSION: 1.5
+    GOROOT: c:\go
+    DOWNLOADPLATFORM: "x64"
+
+install:
+  - choco install mingw
+  - SET PATH=c:\tools\mingw64\bin;%PATH%
+  # - Download COM Server
+  - ps: Start-FileDownload "https://github.com/go-ole/test-com-server/releases/download/v1.0.2/test-com-server-${env:DOWNLOADPLATFORM}.zip"
+  - 7z e test-com-server-%DOWNLOADPLATFORM%.zip -oc:\gopath\src\github.com\go-ole\go-ole > NUL
+  - c:\gopath\src\github.com\go-ole\go-ole\build\register-assembly.bat
+  # - set
+  - go version
+  - go env
+  - go get -u golang.org/x/tools/cmd/cover
+  - go get -u golang.org/x/tools/cmd/godoc
+  - go get -u golang.org/x/tools/cmd/stringer
+
+build_script:
+  - cd c:\gopath\src\github.com\go-ole\go-ole
+  - go get -v -t ./...
+  - go build
+  - go test -v -cover ./...
+
+# disable automatic tests
+test: off
+
+# disable deployment
+deploy: off

vendor/github.com/go-ole/go-ole/com.go

@@ -0,0 +1,344 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+var (
+	procCoInitialize, _            = modole32.FindProc("CoInitialize")
+	procCoInitializeEx, _          = modole32.FindProc("CoInitializeEx")
+	procCoUninitialize, _          = modole32.FindProc("CoUninitialize")
+	procCoCreateInstance, _        = modole32.FindProc("CoCreateInstance")
+	procCoTaskMemFree, _           = modole32.FindProc("CoTaskMemFree")
+	procCLSIDFromProgID, _         = modole32.FindProc("CLSIDFromProgID")
+	procCLSIDFromString, _         = modole32.FindProc("CLSIDFromString")
+	procStringFromCLSID, _         = modole32.FindProc("StringFromCLSID")
+	procStringFromIID, _           = modole32.FindProc("StringFromIID")
+	procIIDFromString, _           = modole32.FindProc("IIDFromString")
+	procCoGetObject, _             = modole32.FindProc("CoGetObject")
+	procGetUserDefaultLCID, _      = modkernel32.FindProc("GetUserDefaultLCID")
+	procCopyMemory, _              = modkernel32.FindProc("RtlMoveMemory")
+	procVariantInit, _             = modoleaut32.FindProc("VariantInit")
+	procVariantClear, _            = modoleaut32.FindProc("VariantClear")
+	procVariantTimeToSystemTime, _ = modoleaut32.FindProc("VariantTimeToSystemTime")
+	procSysAllocString, _          = modoleaut32.FindProc("SysAllocString")
+	procSysAllocStringLen, _       = modoleaut32.FindProc("SysAllocStringLen")
+	procSysFreeString, _           = modoleaut32.FindProc("SysFreeString")
+	procSysStringLen, _            = modoleaut32.FindProc("SysStringLen")
+	procCreateDispTypeInfo, _      = modoleaut32.FindProc("CreateDispTypeInfo")
+	procCreateStdDispatch, _       = modoleaut32.FindProc("CreateStdDispatch")
+	procGetActiveObject, _         = modoleaut32.FindProc("GetActiveObject")
+
+	procGetMessageW, _      = moduser32.FindProc("GetMessageW")
+	procDispatchMessageW, _ = moduser32.FindProc("DispatchMessageW")
+)
+
+// coInitialize initializes COM library on current thread.
+//
+// MSDN documentation suggests that this function should not be called. Call
+// CoInitializeEx() instead. The reason has to do with threading and this
+// function is only for single-threaded apartments.
+//
+// That said, most users of the library have gotten away with just this
+// function. If you are experiencing threading issues, then use
+// CoInitializeEx().
+func coInitialize() (err error) {
+	// http://msdn.microsoft.com/en-us/library/windows/desktop/ms678543(v=vs.85).aspx
+	// Suggests that no value should be passed to CoInitialized.
+	// Could just be Call() since the parameter is optional. <-- Needs testing to be sure.
+	hr, _, _ := procCoInitialize.Call(uintptr(0))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// coInitializeEx initializes COM library with concurrency model.
+func coInitializeEx(coinit uint32) (err error) {
+	// http://msdn.microsoft.com/en-us/library/windows/desktop/ms695279(v=vs.85).aspx
+	// Suggests that the first parameter is not only optional but should always be NULL.
+	hr, _, _ := procCoInitializeEx.Call(uintptr(0), uintptr(coinit))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// CoInitialize initializes COM library on current thread.
+//
+// MSDN documentation suggests that this function should not be called. Call
+// CoInitializeEx() instead. The reason has to do with threading and this
+// function is only for single-threaded apartments.
+//
+// That said, most users of the library have gotten away with just this
+// function. If you are experiencing threading issues, then use
+// CoInitializeEx().
+func CoInitialize(p uintptr) (err error) {
+	// p is ignored and won't be used.
+	// Avoid any variable not used errors.
+	p = uintptr(0)
+	return coInitialize()
+}
+
+// CoInitializeEx initializes COM library with concurrency model.
+func CoInitializeEx(p uintptr, coinit uint32) (err error) {
+	// Avoid any variable not used errors.
+	p = uintptr(0)
+	return coInitializeEx(coinit)
+}
+
+// CoUninitialize uninitializes COM Library.
+func CoUninitialize() {
+	procCoUninitialize.Call()
+}
+
+// CoTaskMemFree frees memory pointer.
+func CoTaskMemFree(memptr uintptr) {
+	procCoTaskMemFree.Call(memptr)
+}
+
+// CLSIDFromProgID retrieves Class Identifier with the given Program Identifier.
+//
+// The Programmatic Identifier must be registered, because it will be looked up
+// in the Windows Registry. The registry entry has the following keys: CLSID,
+// Insertable, Protocol and Shell
+// (https://msdn.microsoft.com/en-us/library/dd542719(v=vs.85).aspx).
+//
+// programID identifies the class id with less precision and is not guaranteed
+// to be unique. These are usually found in the registry under
+// HKEY_LOCAL_MACHINE\SOFTWARE\Classes, usually with the format of
+// "Program.Component.Version" with version being optional.
+//
+// CLSIDFromProgID in Windows API.
+func CLSIDFromProgID(progId string) (clsid *GUID, err error) {
+	var guid GUID
+	lpszProgID := uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(progId)))
+	hr, _, _ := procCLSIDFromProgID.Call(lpszProgID, uintptr(unsafe.Pointer(&guid)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	clsid = &guid
+	return
+}
+
+// CLSIDFromString retrieves Class ID from string representation.
+//
+// This is technically the string version of the GUID and will convert the
+// string to object.
+//
+// CLSIDFromString in Windows API.
+func CLSIDFromString(str string) (clsid *GUID, err error) {
+	var guid GUID
+	lpsz := uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(str)))
+	hr, _, _ := procCLSIDFromString.Call(lpsz, uintptr(unsafe.Pointer(&guid)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	clsid = &guid
+	return
+}
+
+// StringFromCLSID returns GUID formated string from GUID object.
+func StringFromCLSID(clsid *GUID) (str string, err error) {
+	var p *uint16
+	hr, _, _ := procStringFromCLSID.Call(uintptr(unsafe.Pointer(clsid)), uintptr(unsafe.Pointer(&p)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	str = LpOleStrToString(p)
+	return
+}
+
+// IIDFromString returns GUID from program ID.
+func IIDFromString(progId string) (clsid *GUID, err error) {
+	var guid GUID
+	lpsz := uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(progId)))
+	hr, _, _ := procIIDFromString.Call(lpsz, uintptr(unsafe.Pointer(&guid)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	clsid = &guid
+	return
+}
+
+// StringFromIID returns GUID formatted string from GUID object.
+func StringFromIID(iid *GUID) (str string, err error) {
+	var p *uint16
+	hr, _, _ := procStringFromIID.Call(uintptr(unsafe.Pointer(iid)), uintptr(unsafe.Pointer(&p)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	str = LpOleStrToString(p)
+	return
+}
+
+// CreateInstance of single uninitialized object with GUID.
+func CreateInstance(clsid *GUID, iid *GUID) (unk *IUnknown, err error) {
+	if iid == nil {
+		iid = IID_IUnknown
+	}
+	hr, _, _ := procCoCreateInstance.Call(
+		uintptr(unsafe.Pointer(clsid)),
+		0,
+		CLSCTX_SERVER,
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(&unk)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// GetActiveObject retrieves pointer to active object.
+func GetActiveObject(clsid *GUID, iid *GUID) (unk *IUnknown, err error) {
+	if iid == nil {
+		iid = IID_IUnknown
+	}
+	hr, _, _ := procGetActiveObject.Call(
+		uintptr(unsafe.Pointer(clsid)),
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(&unk)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+type BindOpts struct {
+	CbStruct          uint32
+	GrfFlags          uint32
+	GrfMode           uint32
+	TickCountDeadline uint32
+}
+
+// GetObject retrieves pointer to active object.
+func GetObject(programID string, bindOpts *BindOpts, iid *GUID) (unk *IUnknown, err error) {
+	if bindOpts != nil {
+		bindOpts.CbStruct = uint32(unsafe.Sizeof(BindOpts{}))
+	}
+	if iid == nil {
+		iid = IID_IUnknown
+	}
+	hr, _, _ := procCoGetObject.Call(
+		uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(programID))),
+		uintptr(unsafe.Pointer(bindOpts)),
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(&unk)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// VariantInit initializes variant.
+func VariantInit(v *VARIANT) (err error) {
+	hr, _, _ := procVariantInit.Call(uintptr(unsafe.Pointer(v)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// VariantClear clears value in Variant settings to VT_EMPTY.
+func VariantClear(v *VARIANT) (err error) {
+	hr, _, _ := procVariantClear.Call(uintptr(unsafe.Pointer(v)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// SysAllocString allocates memory for string and copies string into memory.
+func SysAllocString(v string) (ss *int16) {
+	pss, _, _ := procSysAllocString.Call(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(v))))
+	ss = (*int16)(unsafe.Pointer(pss))
+	return
+}
+
+// SysAllocStringLen copies up to length of given string returning pointer.
+func SysAllocStringLen(v string) (ss *int16) {
+	utf16 := utf16.Encode([]rune(v + "\x00"))
+	ptr := &utf16[0]
+
+	pss, _, _ := procSysAllocStringLen.Call(uintptr(unsafe.Pointer(ptr)), uintptr(len(utf16)-1))
+	ss = (*int16)(unsafe.Pointer(pss))
+	return
+}
+
+// SysFreeString frees string system memory. This must be called with SysAllocString.
+func SysFreeString(v *int16) (err error) {
+	hr, _, _ := procSysFreeString.Call(uintptr(unsafe.Pointer(v)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// SysStringLen is the length of the system allocated string.
+func SysStringLen(v *int16) uint32 {
+	l, _, _ := procSysStringLen.Call(uintptr(unsafe.Pointer(v)))
+	return uint32(l)
+}
+
+// CreateStdDispatch provides default IDispatch implementation for IUnknown.
+//
+// This handles default IDispatch implementation for objects. It haves a few
+// limitations with only supporting one language. It will also only return
+// default exception codes.
+func CreateStdDispatch(unk *IUnknown, v uintptr, ptinfo *IUnknown) (disp *IDispatch, err error) {
+	hr, _, _ := procCreateStdDispatch.Call(
+		uintptr(unsafe.Pointer(unk)),
+		v,
+		uintptr(unsafe.Pointer(ptinfo)),
+		uintptr(unsafe.Pointer(&disp)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// CreateDispTypeInfo provides default ITypeInfo implementation for IDispatch.
+//
+// This will not handle the full implementation of the interface.
+func CreateDispTypeInfo(idata *INTERFACEDATA) (pptinfo *IUnknown, err error) {
+	hr, _, _ := procCreateDispTypeInfo.Call(
+		uintptr(unsafe.Pointer(idata)),
+		uintptr(GetUserDefaultLCID()),
+		uintptr(unsafe.Pointer(&pptinfo)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// copyMemory moves location of a block of memory.
+func copyMemory(dest unsafe.Pointer, src unsafe.Pointer, length uint32) {
+	procCopyMemory.Call(uintptr(dest), uintptr(src), uintptr(length))
+}
+
+// GetUserDefaultLCID retrieves current user default locale.
+func GetUserDefaultLCID() (lcid uint32) {
+	ret, _, _ := procGetUserDefaultLCID.Call()
+	lcid = uint32(ret)
+	return
+}
+
+// GetMessage in message queue from runtime.
+//
+// This function appears to block. PeekMessage does not block.
+func GetMessage(msg *Msg, hwnd uint32, MsgFilterMin uint32, MsgFilterMax uint32) (ret int32, err error) {
+	r0, _, err := procGetMessageW.Call(uintptr(unsafe.Pointer(msg)), uintptr(hwnd), uintptr(MsgFilterMin), uintptr(MsgFilterMax))
+	ret = int32(r0)
+	return
+}
+
+// DispatchMessage to window procedure.
+func DispatchMessage(msg *Msg) (ret int32) {
+	r0, _, _ := procDispatchMessageW.Call(uintptr(unsafe.Pointer(msg)))
+	ret = int32(r0)
+	return
+}

vendor/github.com/go-ole/go-ole/com_func.go

@@ -0,0 +1,174 @@
+// +build !windows
+
+package ole
+
+import (
+	"time"
+	"unsafe"
+)
+
+// coInitialize initializes COM library on current thread.
+//
+// MSDN documentation suggests that this function should not be called. Call
+// CoInitializeEx() instead. The reason has to do with threading and this
+// function is only for single-threaded apartments.
+//
+// That said, most users of the library have gotten away with just this
+// function. If you are experiencing threading issues, then use
+// CoInitializeEx().
+func coInitialize() error {
+	return NewError(E_NOTIMPL)
+}
+
+// coInitializeEx initializes COM library with concurrency model.
+func coInitializeEx(coinit uint32) error {
+	return NewError(E_NOTIMPL)
+}
+
+// CoInitialize initializes COM library on current thread.
+//
+// MSDN documentation suggests that this function should not be called. Call
+// CoInitializeEx() instead. The reason has to do with threading and this
+// function is only for single-threaded apartments.
+//
+// That said, most users of the library have gotten away with just this
+// function. If you are experiencing threading issues, then use
+// CoInitializeEx().
+func CoInitialize(p uintptr) error {
+	return NewError(E_NOTIMPL)
+}
+
+// CoInitializeEx initializes COM library with concurrency model.
+func CoInitializeEx(p uintptr, coinit uint32) error {
+	return NewError(E_NOTIMPL)
+}
+
+// CoUninitialize uninitializes COM Library.
+func CoUninitialize() {}
+
+// CoTaskMemFree frees memory pointer.
+func CoTaskMemFree(memptr uintptr) {}
+
+// CLSIDFromProgID retrieves Class Identifier with the given Program Identifier.
+//
+// The Programmatic Identifier must be registered, because it will be looked up
+// in the Windows Registry. The registry entry has the following keys: CLSID,
+// Insertable, Protocol and Shell
+// (https://msdn.microsoft.com/en-us/library/dd542719(v=vs.85).aspx).
+//
+// programID identifies the class id with less precision and is not guaranteed
+// to be unique. These are usually found in the registry under
+// HKEY_LOCAL_MACHINE\SOFTWARE\Classes, usually with the format of
+// "Program.Component.Version" with version being optional.
+//
+// CLSIDFromProgID in Windows API.
+func CLSIDFromProgID(progId string) (*GUID, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// CLSIDFromString retrieves Class ID from string representation.
+//
+// This is technically the string version of the GUID and will convert the
+// string to object.
+//
+// CLSIDFromString in Windows API.
+func CLSIDFromString(str string) (*GUID, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// StringFromCLSID returns GUID formated string from GUID object.
+func StringFromCLSID(clsid *GUID) (string, error) {
+	return "", NewError(E_NOTIMPL)
+}
+
+// IIDFromString returns GUID from program ID.
+func IIDFromString(progId string) (*GUID, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// StringFromIID returns GUID formatted string from GUID object.
+func StringFromIID(iid *GUID) (string, error) {
+	return "", NewError(E_NOTIMPL)
+}
+
+// CreateInstance of single uninitialized object with GUID.
+func CreateInstance(clsid *GUID, iid *GUID) (*IUnknown, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// GetActiveObject retrieves pointer to active object.
+func GetActiveObject(clsid *GUID, iid *GUID) (*IUnknown, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// VariantInit initializes variant.
+func VariantInit(v *VARIANT) error {
+	return NewError(E_NOTIMPL)
+}
+
+// VariantClear clears value in Variant settings to VT_EMPTY.
+func VariantClear(v *VARIANT) error {
+	return NewError(E_NOTIMPL)
+}
+
+// SysAllocString allocates memory for string and copies string into memory.
+func SysAllocString(v string) *int16 {
+	u := int16(0)
+	return &u
+}
+
+// SysAllocStringLen copies up to length of given string returning pointer.
+func SysAllocStringLen(v string) *int16 {
+	u := int16(0)
+	return &u
+}
+
+// SysFreeString frees string system memory. This must be called with SysAllocString.
+func SysFreeString(v *int16) error {
+	return NewError(E_NOTIMPL)
+}
+
+// SysStringLen is the length of the system allocated string.
+func SysStringLen(v *int16) uint32 {
+	return uint32(0)
+}
+
+// CreateStdDispatch provides default IDispatch implementation for IUnknown.
+//
+// This handles default IDispatch implementation for objects. It haves a few
+// limitations with only supporting one language. It will also only return
+// default exception codes.
+func CreateStdDispatch(unk *IUnknown, v uintptr, ptinfo *IUnknown) (*IDispatch, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// CreateDispTypeInfo provides default ITypeInfo implementation for IDispatch.
+//
+// This will not handle the full implementation of the interface.
+func CreateDispTypeInfo(idata *INTERFACEDATA) (*IUnknown, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// copyMemory moves location of a block of memory.
+func copyMemory(dest unsafe.Pointer, src unsafe.Pointer, length uint32) {}
+
+// GetUserDefaultLCID retrieves current user default locale.
+func GetUserDefaultLCID() uint32 {
+	return uint32(0)
+}
+
+// GetMessage in message queue from runtime.
+//
+// This function appears to block. PeekMessage does not block.
+func GetMessage(msg *Msg, hwnd uint32, MsgFilterMin uint32, MsgFilterMax uint32) (int32, error) {
+	return int32(0), NewError(E_NOTIMPL)
+}
+
+// DispatchMessage to window procedure.
+func DispatchMessage(msg *Msg) int32 {
+	return int32(0)
+}
+
+func GetVariantDate(value uint64) (time.Time, error) {
+	return time.Now(), NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/connect.go

@@ -0,0 +1,192 @@
+package ole
+
+// Connection contains IUnknown for fluent interface interaction.
+//
+// Deprecated. Use oleutil package instead.
+type Connection struct {
+	Object *IUnknown // Access COM
+}
+
+// Initialize COM.
+func (*Connection) Initialize() (err error) {
+	return coInitialize()
+}
+
+// Uninitialize COM.
+func (*Connection) Uninitialize() {
+	CoUninitialize()
+}
+
+// Create IUnknown object based first on ProgId and then from String.
+func (c *Connection) Create(progId string) (err error) {
+	var clsid *GUID
+	clsid, err = CLSIDFromProgID(progId)
+	if err != nil {
+		clsid, err = CLSIDFromString(progId)
+		if err != nil {
+			return
+		}
+	}
+
+	unknown, err := CreateInstance(clsid, IID_IUnknown)
+	if err != nil {
+		return
+	}
+	c.Object = unknown
+
+	return
+}
+
+// Release IUnknown object.
+func (c *Connection) Release() {
+	c.Object.Release()
+}
+
+// Load COM object from list of programIDs or strings.
+func (c *Connection) Load(names ...string) (errors []error) {
+	var tempErrors []error = make([]error, len(names))
+	var numErrors int = 0
+	for _, name := range names {
+		err := c.Create(name)
+		if err != nil {
+			tempErrors = append(tempErrors, err)
+			numErrors += 1
+			continue
+		}
+		break
+	}
+
+	copy(errors, tempErrors[0:numErrors])
+	return
+}
+
+// Dispatch returns Dispatch object.
+func (c *Connection) Dispatch() (object *Dispatch, err error) {
+	dispatch, err := c.Object.QueryInterface(IID_IDispatch)
+	if err != nil {
+		return
+	}
+	object = &Dispatch{dispatch}
+	return
+}
+
+// Dispatch stores IDispatch object.
+type Dispatch struct {
+	Object *IDispatch // Dispatch object.
+}
+
+// Call method on IDispatch with parameters.
+func (d *Dispatch) Call(method string, params ...interface{}) (result *VARIANT, err error) {
+	id, err := d.GetId(method)
+	if err != nil {
+		return
+	}
+
+	result, err = d.Invoke(id, DISPATCH_METHOD, params)
+	return
+}
+
+// MustCall method on IDispatch with parameters.
+func (d *Dispatch) MustCall(method string, params ...interface{}) (result *VARIANT) {
+	id, err := d.GetId(method)
+	if err != nil {
+		panic(err)
+	}
+
+	result, err = d.Invoke(id, DISPATCH_METHOD, params)
+	if err != nil {
+		panic(err)
+	}
+
+	return
+}
+
+// Get property on IDispatch with parameters.
+func (d *Dispatch) Get(name string, params ...interface{}) (result *VARIANT, err error) {
+	id, err := d.GetId(name)
+	if err != nil {
+		return
+	}
+	result, err = d.Invoke(id, DISPATCH_PROPERTYGET, params)
+	return
+}
+
+// MustGet property on IDispatch with parameters.
+func (d *Dispatch) MustGet(name string, params ...interface{}) (result *VARIANT) {
+	id, err := d.GetId(name)
+	if err != nil {
+		panic(err)
+	}
+
+	result, err = d.Invoke(id, DISPATCH_PROPERTYGET, params)
+	if err != nil {
+		panic(err)
+	}
+	return
+}
+
+// Set property on IDispatch with parameters.
+func (d *Dispatch) Set(name string, params ...interface{}) (result *VARIANT, err error) {
+	id, err := d.GetId(name)
+	if err != nil {
+		return
+	}
+	result, err = d.Invoke(id, DISPATCH_PROPERTYPUT, params)
+	return
+}
+
+// MustSet property on IDispatch with parameters.
+func (d *Dispatch) MustSet(name string, params ...interface{}) (result *VARIANT) {
+	id, err := d.GetId(name)
+	if err != nil {
+		panic(err)
+	}
+
+	result, err = d.Invoke(id, DISPATCH_PROPERTYPUT, params)
+	if err != nil {
+		panic(err)
+	}
+	return
+}
+
+// GetId retrieves ID of name on IDispatch.
+func (d *Dispatch) GetId(name string) (id int32, err error) {
+	var dispid []int32
+	dispid, err = d.Object.GetIDsOfName([]string{name})
+	if err != nil {
+		return
+	}
+	id = dispid[0]
+	return
+}
+
+// GetIds retrieves all IDs of names on IDispatch.
+func (d *Dispatch) GetIds(names ...string) (dispid []int32, err error) {
+	dispid, err = d.Object.GetIDsOfName(names)
+	return
+}
+
+// Invoke IDispatch on DisplayID of dispatch type with parameters.
+//
+// There have been problems where if send cascading params..., it would error
+// out because the parameters would be empty.
+func (d *Dispatch) Invoke(id int32, dispatch int16, params []interface{}) (result *VARIANT, err error) {
+	if len(params) < 1 {
+		result, err = d.Object.Invoke(id, dispatch)
+	} else {
+		result, err = d.Object.Invoke(id, dispatch, params...)
+	}
+	return
+}
+
+// Release IDispatch object.
+func (d *Dispatch) Release() {
+	d.Object.Release()
+}
+
+// Connect initializes COM and attempts to load IUnknown based on given names.
+func Connect(names ...string) (connection *Connection) {
+	connection.Initialize()
+	connection.Load(names...)
+	return
+}

vendor/github.com/go-ole/go-ole/constants.go

@@ -0,0 +1,153 @@
+package ole
+
+const (
+	CLSCTX_INPROC_SERVER   = 1
+	CLSCTX_INPROC_HANDLER  = 2
+	CLSCTX_LOCAL_SERVER    = 4
+	CLSCTX_INPROC_SERVER16 = 8
+	CLSCTX_REMOTE_SERVER   = 16
+	CLSCTX_ALL             = CLSCTX_INPROC_SERVER | CLSCTX_INPROC_HANDLER | CLSCTX_LOCAL_SERVER
+	CLSCTX_INPROC          = CLSCTX_INPROC_SERVER | CLSCTX_INPROC_HANDLER
+	CLSCTX_SERVER          = CLSCTX_INPROC_SERVER | CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER
+)
+
+const (
+	COINIT_APARTMENTTHREADED = 0x2
+	COINIT_MULTITHREADED     = 0x0
+	COINIT_DISABLE_OLE1DDE   = 0x4
+	COINIT_SPEED_OVER_MEMORY = 0x8
+)
+
+const (
+	DISPATCH_METHOD         = 1
+	DISPATCH_PROPERTYGET    = 2
+	DISPATCH_PROPERTYPUT    = 4
+	DISPATCH_PROPERTYPUTREF = 8
+)
+
+const (
+	S_OK           = 0x00000000
+	E_UNEXPECTED   = 0x8000FFFF
+	E_NOTIMPL      = 0x80004001
+	E_OUTOFMEMORY  = 0x8007000E
+	E_INVALIDARG   = 0x80070057
+	E_NOINTERFACE  = 0x80004002
+	E_POINTER      = 0x80004003
+	E_HANDLE       = 0x80070006
+	E_ABORT        = 0x80004004
+	E_FAIL         = 0x80004005
+	E_ACCESSDENIED = 0x80070005
+	E_PENDING      = 0x8000000A
+
+	CO_E_CLASSSTRING = 0x800401F3
+)
+
+const (
+	CC_FASTCALL = iota
+	CC_CDECL
+	CC_MSCPASCAL
+	CC_PASCAL = CC_MSCPASCAL
+	CC_MACPASCAL
+	CC_STDCALL
+	CC_FPFASTCALL
+	CC_SYSCALL
+	CC_MPWCDECL
+	CC_MPWPASCAL
+	CC_MAX = CC_MPWPASCAL
+)
+
+type VT uint16
+
+const (
+	VT_EMPTY           VT = 0x0
+	VT_NULL            VT = 0x1
+	VT_I2              VT = 0x2
+	VT_I4              VT = 0x3
+	VT_R4              VT = 0x4
+	VT_R8              VT = 0x5
+	VT_CY              VT = 0x6
+	VT_DATE            VT = 0x7
+	VT_BSTR            VT = 0x8
+	VT_DISPATCH        VT = 0x9
+	VT_ERROR           VT = 0xa
+	VT_BOOL            VT = 0xb
+	VT_VARIANT         VT = 0xc
+	VT_UNKNOWN         VT = 0xd
+	VT_DECIMAL         VT = 0xe
+	VT_I1              VT = 0x10
+	VT_UI1             VT = 0x11
+	VT_UI2             VT = 0x12
+	VT_UI4             VT = 0x13
+	VT_I8              VT = 0x14
+	VT_UI8             VT = 0x15
+	VT_INT             VT = 0x16
+	VT_UINT            VT = 0x17
+	VT_VOID            VT = 0x18
+	VT_HRESULT         VT = 0x19
+	VT_PTR             VT = 0x1a
+	VT_SAFEARRAY       VT = 0x1b
+	VT_CARRAY          VT = 0x1c
+	VT_USERDEFINED     VT = 0x1d
+	VT_LPSTR           VT = 0x1e
+	VT_LPWSTR          VT = 0x1f
+	VT_RECORD          VT = 0x24
+	VT_INT_PTR         VT = 0x25
+	VT_UINT_PTR        VT = 0x26
+	VT_FILETIME        VT = 0x40
+	VT_BLOB            VT = 0x41
+	VT_STREAM          VT = 0x42
+	VT_STORAGE         VT = 0x43
+	VT_STREAMED_OBJECT VT = 0x44
+	VT_STORED_OBJECT   VT = 0x45
+	VT_BLOB_OBJECT     VT = 0x46
+	VT_CF              VT = 0x47
+	VT_CLSID           VT = 0x48
+	VT_BSTR_BLOB       VT = 0xfff
+	VT_VECTOR          VT = 0x1000
+	VT_ARRAY           VT = 0x2000
+	VT_BYREF           VT = 0x4000
+	VT_RESERVED        VT = 0x8000
+	VT_ILLEGAL         VT = 0xffff
+	VT_ILLEGALMASKED   VT = 0xfff
+	VT_TYPEMASK        VT = 0xfff
+)
+
+const (
+	DISPID_UNKNOWN     = -1
+	DISPID_VALUE       = 0
+	DISPID_PROPERTYPUT = -3
+	DISPID_NEWENUM     = -4
+	DISPID_EVALUATE    = -5
+	DISPID_CONSTRUCTOR = -6
+	DISPID_DESTRUCTOR  = -7
+	DISPID_COLLECT     = -8
+)
+
+const (
+	TKIND_ENUM      = 1
+	TKIND_RECORD    = 2
+	TKIND_MODULE    = 3
+	TKIND_INTERFACE = 4
+	TKIND_DISPATCH  = 5
+	TKIND_COCLASS   = 6
+	TKIND_ALIAS     = 7
+	TKIND_UNION     = 8
+	TKIND_MAX       = 9
+)
+
+// Safe Array Feature Flags
+
+const (
+	FADF_AUTO        = 0x0001
+	FADF_STATIC      = 0x0002
+	FADF_EMBEDDED    = 0x0004
+	FADF_FIXEDSIZE   = 0x0010
+	FADF_RECORD      = 0x0020
+	FADF_HAVEIID     = 0x0040
+	FADF_HAVEVARTYPE = 0x0080
+	FADF_BSTR        = 0x0100
+	FADF_UNKNOWN     = 0x0200
+	FADF_DISPATCH    = 0x0400
+	FADF_VARIANT     = 0x0800
+	FADF_RESERVED    = 0xF008
+)

vendor/github.com/go-ole/go-ole/error.go

@@ -0,0 +1,51 @@
+package ole
+
+// OleError stores COM errors.
+type OleError struct {
+	hr          uintptr
+	description string
+	subError    error
+}
+
+// NewError creates new error with HResult.
+func NewError(hr uintptr) *OleError {
+	return &OleError{hr: hr}
+}
+
+// NewErrorWithDescription creates new COM error with HResult and description.
+func NewErrorWithDescription(hr uintptr, description string) *OleError {
+	return &OleError{hr: hr, description: description}
+}
+
+// NewErrorWithSubError creates new COM error with parent error.
+func NewErrorWithSubError(hr uintptr, description string, err error) *OleError {
+	return &OleError{hr: hr, description: description, subError: err}
+}
+
+// Code is the HResult.
+func (v *OleError) Code() uintptr {
+	return uintptr(v.hr)
+}
+
+// String description, either manually set or format message with error code.
+func (v *OleError) String() string {
+	if v.description != "" {
+		return errstr(int(v.hr)) + " (" + v.description + ")"
+	}
+	return errstr(int(v.hr))
+}
+
+// Error implements error interface.
+func (v *OleError) Error() string {
+	return v.String()
+}
+
+// Description retrieves error summary, if there is one.
+func (v *OleError) Description() string {
+	return v.description
+}
+
+// SubError returns parent error, if there is one.
+func (v *OleError) SubError() error {
+	return v.subError
+}

vendor/github.com/go-ole/go-ole/error_func.go

@@ -0,0 +1,8 @@
+// +build !windows
+
+package ole
+
+// errstr converts error code to string.
+func errstr(errno int) string {
+	return ""
+}

vendor/github.com/go-ole/go-ole/error_windows.go

@@ -0,0 +1,24 @@
+// +build windows
+
+package ole
+
+import (
+	"fmt"
+	"syscall"
+	"unicode/utf16"
+)
+
+// errstr converts error code to string.
+func errstr(errno int) string {
+	// ask windows for the remaining errors
+	var flags uint32 = syscall.FORMAT_MESSAGE_FROM_SYSTEM | syscall.FORMAT_MESSAGE_ARGUMENT_ARRAY | syscall.FORMAT_MESSAGE_IGNORE_INSERTS
+	b := make([]uint16, 300)
+	n, err := syscall.FormatMessage(flags, 0, uint32(errno), 0, b, nil)
+	if err != nil {
+		return fmt.Sprintf("error %d (FormatMessage failed with: %v)", errno, err)
+	}
+	// trim terminating \r and \n
+	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
+	}
+	return string(utf16.Decode(b[:n]))
+}

vendor/github.com/go-ole/go-ole/go.mod

@@ -0,0 +1,3 @@
+module github.com/go-ole/go-ole
+
+go 1.12

vendor/github.com/go-ole/go-ole/guid.go

@@ -0,0 +1,284 @@
+package ole
+
+var (
+	// IID_NULL is null Interface ID, used when no other Interface ID is known.
+	IID_NULL = NewGUID("{00000000-0000-0000-0000-000000000000}")
+
+	// IID_IUnknown is for IUnknown interfaces.
+	IID_IUnknown = NewGUID("{00000000-0000-0000-C000-000000000046}")
+
+	// IID_IDispatch is for IDispatch interfaces.
+	IID_IDispatch = NewGUID("{00020400-0000-0000-C000-000000000046}")
+
+	// IID_IEnumVariant is for IEnumVariant interfaces
+	IID_IEnumVariant = NewGUID("{00020404-0000-0000-C000-000000000046}")
+
+	// IID_IConnectionPointContainer is for IConnectionPointContainer interfaces.
+	IID_IConnectionPointContainer = NewGUID("{B196B284-BAB4-101A-B69C-00AA00341D07}")
+
+	// IID_IConnectionPoint is for IConnectionPoint interfaces.
+	IID_IConnectionPoint = NewGUID("{B196B286-BAB4-101A-B69C-00AA00341D07}")
+
+	// IID_IInspectable is for IInspectable interfaces.
+	IID_IInspectable = NewGUID("{AF86E2E0-B12D-4C6A-9C5A-D7AA65101E90}")
+
+	// IID_IProvideClassInfo is for IProvideClassInfo interfaces.
+	IID_IProvideClassInfo = NewGUID("{B196B283-BAB4-101A-B69C-00AA00341D07}")
+)
+
+// These are for testing and not part of any library.
+var (
+	// IID_ICOMTestString is for ICOMTestString interfaces.
+	//
+	// {E0133EB4-C36F-469A-9D3D-C66B84BE19ED}
+	IID_ICOMTestString = NewGUID("{E0133EB4-C36F-469A-9D3D-C66B84BE19ED}")
+
+	// IID_ICOMTestInt8 is for ICOMTestInt8 interfaces.
+	//
+	// {BEB06610-EB84-4155-AF58-E2BFF53680B4}
+	IID_ICOMTestInt8 = NewGUID("{BEB06610-EB84-4155-AF58-E2BFF53680B4}")
+
+	// IID_ICOMTestInt16 is for ICOMTestInt16 interfaces.
+	//
+	// {DAA3F9FA-761E-4976-A860-8364CE55F6FC}
+	IID_ICOMTestInt16 = NewGUID("{DAA3F9FA-761E-4976-A860-8364CE55F6FC}")
+
+	// IID_ICOMTestInt32 is for ICOMTestInt32 interfaces.
+	//
+	// {E3DEDEE7-38A2-4540-91D1-2EEF1D8891B0}
+	IID_ICOMTestInt32 = NewGUID("{E3DEDEE7-38A2-4540-91D1-2EEF1D8891B0}")
+
+	// IID_ICOMTestInt64 is for ICOMTestInt64 interfaces.
+	//
+	// {8D437CBC-B3ED-485C-BC32-C336432A1623}
+	IID_ICOMTestInt64 = NewGUID("{8D437CBC-B3ED-485C-BC32-C336432A1623}")
+
+	// IID_ICOMTestFloat is for ICOMTestFloat interfaces.
+	//
+	// {BF1ED004-EA02-456A-AA55-2AC8AC6B054C}
+	IID_ICOMTestFloat = NewGUID("{BF1ED004-EA02-456A-AA55-2AC8AC6B054C}")
+
+	// IID_ICOMTestDouble is for ICOMTestDouble interfaces.
+	//
+	// {BF908A81-8687-4E93-999F-D86FAB284BA0}
+	IID_ICOMTestDouble = NewGUID("{BF908A81-8687-4E93-999F-D86FAB284BA0}")
+
+	// IID_ICOMTestBoolean is for ICOMTestBoolean interfaces.
+	//
+	// {D530E7A6-4EE8-40D1-8931-3D63B8605010}
+	IID_ICOMTestBoolean = NewGUID("{D530E7A6-4EE8-40D1-8931-3D63B8605010}")
+
+	// IID_ICOMEchoTestObject is for ICOMEchoTestObject interfaces.
+	//
+	// {6485B1EF-D780-4834-A4FE-1EBB51746CA3}
+	IID_ICOMEchoTestObject = NewGUID("{6485B1EF-D780-4834-A4FE-1EBB51746CA3}")
+
+	// IID_ICOMTestTypes is for ICOMTestTypes interfaces.
+	//
+	// {CCA8D7AE-91C0-4277-A8B3-FF4EDF28D3C0}
+	IID_ICOMTestTypes = NewGUID("{CCA8D7AE-91C0-4277-A8B3-FF4EDF28D3C0}")
+
+	// CLSID_COMEchoTestObject is for COMEchoTestObject class.
+	//
+	// {3C24506A-AE9E-4D50-9157-EF317281F1B0}
+	CLSID_COMEchoTestObject = NewGUID("{3C24506A-AE9E-4D50-9157-EF317281F1B0}")
+
+	// CLSID_COMTestScalarClass is for COMTestScalarClass class.
+	//
+	// {865B85C5-0334-4AC6-9EF6-AACEC8FC5E86}
+	CLSID_COMTestScalarClass = NewGUID("{865B85C5-0334-4AC6-9EF6-AACEC8FC5E86}")
+)
+
+const hextable = "0123456789ABCDEF"
+const emptyGUID = "{00000000-0000-0000-0000-000000000000}"
+
+// GUID is Windows API specific GUID type.
+//
+// This exists to match Windows GUID type for direct passing for COM.
+// Format is in xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxxxxxx.
+type GUID struct {
+	Data1 uint32
+	Data2 uint16
+	Data3 uint16
+	Data4 [8]byte
+}
+
+// NewGUID converts the given string into a globally unique identifier that is
+// compliant with the Windows API.
+//
+// The supplied string may be in any of these formats:
+//
+//  XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+//  XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX
+//  {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}
+//
+// The conversion of the supplied string is not case-sensitive.
+func NewGUID(guid string) *GUID {
+	d := []byte(guid)
+	var d1, d2, d3, d4a, d4b []byte
+
+	switch len(d) {
+	case 38:
+		if d[0] != '{' || d[37] != '}' {
+			return nil
+		}
+		d = d[1:37]
+		fallthrough
+	case 36:
+		if d[8] != '-' || d[13] != '-' || d[18] != '-' || d[23] != '-' {
+			return nil
+		}
+		d1 = d[0:8]
+		d2 = d[9:13]
+		d3 = d[14:18]
+		d4a = d[19:23]
+		d4b = d[24:36]
+	case 32:
+		d1 = d[0:8]
+		d2 = d[8:12]
+		d3 = d[12:16]
+		d4a = d[16:20]
+		d4b = d[20:32]
+	default:
+		return nil
+	}
+
+	var g GUID
+	var ok1, ok2, ok3, ok4 bool
+	g.Data1, ok1 = decodeHexUint32(d1)
+	g.Data2, ok2 = decodeHexUint16(d2)
+	g.Data3, ok3 = decodeHexUint16(d3)
+	g.Data4, ok4 = decodeHexByte64(d4a, d4b)
+	if ok1 && ok2 && ok3 && ok4 {
+		return &g
+	}
+	return nil
+}
+
+func decodeHexUint32(src []byte) (value uint32, ok bool) {
+	var b1, b2, b3, b4 byte
+	var ok1, ok2, ok3, ok4 bool
+	b1, ok1 = decodeHexByte(src[0], src[1])
+	b2, ok2 = decodeHexByte(src[2], src[3])
+	b3, ok3 = decodeHexByte(src[4], src[5])
+	b4, ok4 = decodeHexByte(src[6], src[7])
+	value = (uint32(b1) << 24) | (uint32(b2) << 16) | (uint32(b3) << 8) | uint32(b4)
+	ok = ok1 && ok2 && ok3 && ok4
+	return
+}
+
+func decodeHexUint16(src []byte) (value uint16, ok bool) {
+	var b1, b2 byte
+	var ok1, ok2 bool
+	b1, ok1 = decodeHexByte(src[0], src[1])
+	b2, ok2 = decodeHexByte(src[2], src[3])
+	value = (uint16(b1) << 8) | uint16(b2)
+	ok = ok1 && ok2
+	return
+}
+
+func decodeHexByte64(s1 []byte, s2 []byte) (value [8]byte, ok bool) {
+	var ok1, ok2, ok3, ok4, ok5, ok6, ok7, ok8 bool
+	value[0], ok1 = decodeHexByte(s1[0], s1[1])
+	value[1], ok2 = decodeHexByte(s1[2], s1[3])
+	value[2], ok3 = decodeHexByte(s2[0], s2[1])
+	value[3], ok4 = decodeHexByte(s2[2], s2[3])
+	value[4], ok5 = decodeHexByte(s2[4], s2[5])
+	value[5], ok6 = decodeHexByte(s2[6], s2[7])
+	value[6], ok7 = decodeHexByte(s2[8], s2[9])
+	value[7], ok8 = decodeHexByte(s2[10], s2[11])
+	ok = ok1 && ok2 && ok3 && ok4 && ok5 && ok6 && ok7 && ok8
+	return
+}
+
+func decodeHexByte(c1, c2 byte) (value byte, ok bool) {
+	var n1, n2 byte
+	var ok1, ok2 bool
+	n1, ok1 = decodeHexChar(c1)
+	n2, ok2 = decodeHexChar(c2)
+	value = (n1 << 4) | n2
+	ok = ok1 && ok2
+	return
+}
+
+func decodeHexChar(c byte) (byte, bool) {
+	switch {
+	case '0' <= c && c <= '9':
+		return c - '0', true
+	case 'a' <= c && c <= 'f':
+		return c - 'a' + 10, true
+	case 'A' <= c && c <= 'F':
+		return c - 'A' + 10, true
+	}
+
+	return 0, false
+}
+
+// String converts the GUID to string form. It will adhere to this pattern:
+//
+//  {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}
+//
+// If the GUID is nil, the string representation of an empty GUID is returned:
+//
+//  {00000000-0000-0000-0000-000000000000}
+func (guid *GUID) String() string {
+	if guid == nil {
+		return emptyGUID
+	}
+
+	var c [38]byte
+	c[0] = '{'
+	putUint32Hex(c[1:9], guid.Data1)
+	c[9] = '-'
+	putUint16Hex(c[10:14], guid.Data2)
+	c[14] = '-'
+	putUint16Hex(c[15:19], guid.Data3)
+	c[19] = '-'
+	putByteHex(c[20:24], guid.Data4[0:2])
+	c[24] = '-'
+	putByteHex(c[25:37], guid.Data4[2:8])
+	c[37] = '}'
+	return string(c[:])
+}
+
+func putUint32Hex(b []byte, v uint32) {
+	b[0] = hextable[byte(v>>24)>>4]
+	b[1] = hextable[byte(v>>24)&0x0f]
+	b[2] = hextable[byte(v>>16)>>4]
+	b[3] = hextable[byte(v>>16)&0x0f]
+	b[4] = hextable[byte(v>>8)>>4]
+	b[5] = hextable[byte(v>>8)&0x0f]
+	b[6] = hextable[byte(v)>>4]
+	b[7] = hextable[byte(v)&0x0f]
+}
+
+func putUint16Hex(b []byte, v uint16) {
+	b[0] = hextable[byte(v>>8)>>4]
+	b[1] = hextable[byte(v>>8)&0x0f]
+	b[2] = hextable[byte(v)>>4]
+	b[3] = hextable[byte(v)&0x0f]
+}
+
+func putByteHex(dst, src []byte) {
+	for i := 0; i < len(src); i++ {
+		dst[i*2] = hextable[src[i]>>4]
+		dst[i*2+1] = hextable[src[i]&0x0f]
+	}
+}
+
+// IsEqualGUID compares two GUID.
+//
+// Not constant time comparison.
+func IsEqualGUID(guid1 *GUID, guid2 *GUID) bool {
+	return guid1.Data1 == guid2.Data1 &&
+		guid1.Data2 == guid2.Data2 &&
+		guid1.Data3 == guid2.Data3 &&
+		guid1.Data4[0] == guid2.Data4[0] &&
+		guid1.Data4[1] == guid2.Data4[1] &&
+		guid1.Data4[2] == guid2.Data4[2] &&
+		guid1.Data4[3] == guid2.Data4[3] &&
+		guid1.Data4[4] == guid2.Data4[4] &&
+		guid1.Data4[5] == guid2.Data4[5] &&
+		guid1.Data4[6] == guid2.Data4[6] &&
+		guid1.Data4[7] == guid2.Data4[7]
+}

vendor/github.com/go-ole/go-ole/iconnectionpoint.go

@@ -0,0 +1,20 @@
+package ole
+
+import "unsafe"
+
+type IConnectionPoint struct {
+	IUnknown
+}
+
+type IConnectionPointVtbl struct {
+	IUnknownVtbl
+	GetConnectionInterface      uintptr
+	GetConnectionPointContainer uintptr
+	Advise                      uintptr
+	Unadvise                    uintptr
+	EnumConnections             uintptr
+}
+
+func (v *IConnectionPoint) VTable() *IConnectionPointVtbl {
+	return (*IConnectionPointVtbl)(unsafe.Pointer(v.RawVTable))
+}

vendor/github.com/go-ole/go-ole/iconnectionpoint_func.go

@@ -0,0 +1,21 @@
+// +build !windows
+
+package ole
+
+import "unsafe"
+
+func (v *IConnectionPoint) GetConnectionInterface(piid **GUID) int32 {
+	return int32(0)
+}
+
+func (v *IConnectionPoint) Advise(unknown *IUnknown) (uint32, error) {
+	return uint32(0), NewError(E_NOTIMPL)
+}
+
+func (v *IConnectionPoint) Unadvise(cookie uint32) error {
+	return NewError(E_NOTIMPL)
+}
+
+func (v *IConnectionPoint) EnumConnections(p *unsafe.Pointer) (err error) {
+	return NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/iconnectionpoint_windows.go

@@ -0,0 +1,43 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func (v *IConnectionPoint) GetConnectionInterface(piid **GUID) int32 {
+	// XXX: This doesn't look like it does what it's supposed to
+	return release((*IUnknown)(unsafe.Pointer(v)))
+}
+
+func (v *IConnectionPoint) Advise(unknown *IUnknown) (cookie uint32, err error) {
+	hr, _, _ := syscall.Syscall(
+		v.VTable().Advise,
+		3,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(unknown)),
+		uintptr(unsafe.Pointer(&cookie)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func (v *IConnectionPoint) Unadvise(cookie uint32) (err error) {
+	hr, _, _ := syscall.Syscall(
+		v.VTable().Unadvise,
+		2,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(cookie),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func (v *IConnectionPoint) EnumConnections(p *unsafe.Pointer) error {
+	return NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/iconnectionpointcontainer.go

@@ -0,0 +1,17 @@
+package ole
+
+import "unsafe"
+
+type IConnectionPointContainer struct {
+	IUnknown
+}
+
+type IConnectionPointContainerVtbl struct {
+	IUnknownVtbl
+	EnumConnectionPoints uintptr
+	FindConnectionPoint  uintptr
+}
+
+func (v *IConnectionPointContainer) VTable() *IConnectionPointContainerVtbl {
+	return (*IConnectionPointContainerVtbl)(unsafe.Pointer(v.RawVTable))
+}

vendor/github.com/go-ole/go-ole/iconnectionpointcontainer_func.go

@@ -0,0 +1,11 @@
+// +build !windows
+
+package ole
+
+func (v *IConnectionPointContainer) EnumConnectionPoints(points interface{}) error {
+	return NewError(E_NOTIMPL)
+}
+
+func (v *IConnectionPointContainer) FindConnectionPoint(iid *GUID, point **IConnectionPoint) error {
+	return NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/iconnectionpointcontainer_windows.go

@@ -0,0 +1,25 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func (v *IConnectionPointContainer) EnumConnectionPoints(points interface{}) error {
+	return NewError(E_NOTIMPL)
+}
+
+func (v *IConnectionPointContainer) FindConnectionPoint(iid *GUID, point **IConnectionPoint) (err error) {
+	hr, _, _ := syscall.Syscall(
+		v.VTable().FindConnectionPoint,
+		3,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(point)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/idispatch.go

@@ -0,0 +1,94 @@
+package ole
+
+import "unsafe"
+
+type IDispatch struct {
+	IUnknown
+}
+
+type IDispatchVtbl struct {
+	IUnknownVtbl
+	GetTypeInfoCount uintptr
+	GetTypeInfo      uintptr
+	GetIDsOfNames    uintptr
+	Invoke           uintptr
+}
+
+func (v *IDispatch) VTable() *IDispatchVtbl {
+	return (*IDispatchVtbl)(unsafe.Pointer(v.RawVTable))
+}
+
+func (v *IDispatch) GetIDsOfName(names []string) (dispid []int32, err error) {
+	dispid, err = getIDsOfName(v, names)
+	return
+}
+
+func (v *IDispatch) Invoke(dispid int32, dispatch int16, params ...interface{}) (result *VARIANT, err error) {
+	result, err = invoke(v, dispid, dispatch, params...)
+	return
+}
+
+func (v *IDispatch) GetTypeInfoCount() (c uint32, err error) {
+	c, err = getTypeInfoCount(v)
+	return
+}
+
+func (v *IDispatch) GetTypeInfo() (tinfo *ITypeInfo, err error) {
+	tinfo, err = getTypeInfo(v)
+	return
+}
+
+// GetSingleIDOfName is a helper that returns single display ID for IDispatch name.
+//
+// This replaces the common pattern of attempting to get a single name from the list of available
+// IDs. It gives the first ID, if it is available.
+func (v *IDispatch) GetSingleIDOfName(name string) (displayID int32, err error) {
+	var displayIDs []int32
+	displayIDs, err = v.GetIDsOfName([]string{name})
+	if err != nil {
+		return
+	}
+	displayID = displayIDs[0]
+	return
+}
+
+// InvokeWithOptionalArgs accepts arguments as an array, works like Invoke.
+//
+// Accepts name and will attempt to retrieve Display ID to pass to Invoke.
+//
+// Passing params as an array is a workaround that could be fixed in later versions of Go that
+// prevent passing empty params. During testing it was discovered that this is an acceptable way of
+// getting around not being able to pass params normally.
+func (v *IDispatch) InvokeWithOptionalArgs(name string, dispatch int16, params []interface{}) (result *VARIANT, err error) {
+	displayID, err := v.GetSingleIDOfName(name)
+	if err != nil {
+		return
+	}
+
+	if len(params) < 1 {
+		result, err = v.Invoke(displayID, dispatch)
+	} else {
+		result, err = v.Invoke(displayID, dispatch, params...)
+	}
+
+	return
+}
+
+// CallMethod invokes named function with arguments on object.
+func (v *IDispatch) CallMethod(name string, params ...interface{}) (*VARIANT, error) {
+	return v.InvokeWithOptionalArgs(name, DISPATCH_METHOD, params)
+}
+
+// GetProperty retrieves the property with the name with the ability to pass arguments.
+//
+// Most of the time you will not need to pass arguments as most objects do not allow for this
+// feature. Or at least, should not allow for this feature. Some servers don't follow best practices
+// and this is provided for those edge cases.
+func (v *IDispatch) GetProperty(name string, params ...interface{}) (*VARIANT, error) {
+	return v.InvokeWithOptionalArgs(name, DISPATCH_PROPERTYGET, params)
+}
+
+// PutProperty attempts to mutate a property in the object.
+func (v *IDispatch) PutProperty(name string, params ...interface{}) (*VARIANT, error) {
+	return v.InvokeWithOptionalArgs(name, DISPATCH_PROPERTYPUT, params)
+}

vendor/github.com/go-ole/go-ole/idispatch_func.go

@@ -0,0 +1,19 @@
+// +build !windows
+
+package ole
+
+func getIDsOfName(disp *IDispatch, names []string) ([]int32, error) {
+	return []int32{}, NewError(E_NOTIMPL)
+}
+
+func getTypeInfoCount(disp *IDispatch) (uint32, error) {
+	return uint32(0), NewError(E_NOTIMPL)
+}
+
+func getTypeInfo(disp *IDispatch) (*ITypeInfo, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+func invoke(disp *IDispatch, dispid int32, dispatch int16, params ...interface{}) (*VARIANT, error) {
+	return nil, NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/idispatch_windows.go

@@ -0,0 +1,200 @@
+// +build windows
+
+package ole
+
+import (
+	"math/big"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+func getIDsOfName(disp *IDispatch, names []string) (dispid []int32, err error) {
+	wnames := make([]*uint16, len(names))
+	for i := 0; i < len(names); i++ {
+		wnames[i] = syscall.StringToUTF16Ptr(names[i])
+	}
+	dispid = make([]int32, len(names))
+	namelen := uint32(len(names))
+	hr, _, _ := syscall.Syscall6(
+		disp.VTable().GetIDsOfNames,
+		6,
+		uintptr(unsafe.Pointer(disp)),
+		uintptr(unsafe.Pointer(IID_NULL)),
+		uintptr(unsafe.Pointer(&wnames[0])),
+		uintptr(namelen),
+		uintptr(GetUserDefaultLCID()),
+		uintptr(unsafe.Pointer(&dispid[0])))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func getTypeInfoCount(disp *IDispatch) (c uint32, err error) {
+	hr, _, _ := syscall.Syscall(
+		disp.VTable().GetTypeInfoCount,
+		2,
+		uintptr(unsafe.Pointer(disp)),
+		uintptr(unsafe.Pointer(&c)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func getTypeInfo(disp *IDispatch) (tinfo *ITypeInfo, err error) {
+	hr, _, _ := syscall.Syscall(
+		disp.VTable().GetTypeInfo,
+		3,
+		uintptr(unsafe.Pointer(disp)),
+		uintptr(GetUserDefaultLCID()),
+		uintptr(unsafe.Pointer(&tinfo)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func invoke(disp *IDispatch, dispid int32, dispatch int16, params ...interface{}) (result *VARIANT, err error) {
+	var dispparams DISPPARAMS
+
+	if dispatch&DISPATCH_PROPERTYPUT != 0 {
+		dispnames := [1]int32{DISPID_PROPERTYPUT}
+		dispparams.rgdispidNamedArgs = uintptr(unsafe.Pointer(&dispnames[0]))
+		dispparams.cNamedArgs = 1
+	} else if dispatch&DISPATCH_PROPERTYPUTREF != 0 {
+		dispnames := [1]int32{DISPID_PROPERTYPUT}
+		dispparams.rgdispidNamedArgs = uintptr(unsafe.Pointer(&dispnames[0]))
+		dispparams.cNamedArgs = 1
+	}
+	var vargs []VARIANT
+	if len(params) > 0 {
+		vargs = make([]VARIANT, len(params))
+		for i, v := range params {
+			//n := len(params)-i-1
+			n := len(params) - i - 1
+			VariantInit(&vargs[n])
+			switch vv := v.(type) {
+			case bool:
+				if vv {
+					vargs[n] = NewVariant(VT_BOOL, 0xffff)
+				} else {
+					vargs[n] = NewVariant(VT_BOOL, 0)
+				}
+			case *bool:
+				vargs[n] = NewVariant(VT_BOOL|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*bool)))))
+			case uint8:
+				vargs[n] = NewVariant(VT_I1, int64(v.(uint8)))
+			case *uint8:
+				vargs[n] = NewVariant(VT_I1|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint8)))))
+			case int8:
+				vargs[n] = NewVariant(VT_I1, int64(v.(int8)))
+			case *int8:
+				vargs[n] = NewVariant(VT_I1|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint8)))))
+			case int16:
+				vargs[n] = NewVariant(VT_I2, int64(v.(int16)))
+			case *int16:
+				vargs[n] = NewVariant(VT_I2|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*int16)))))
+			case uint16:
+				vargs[n] = NewVariant(VT_UI2, int64(v.(uint16)))
+			case *uint16:
+				vargs[n] = NewVariant(VT_UI2|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint16)))))
+			case int32:
+				vargs[n] = NewVariant(VT_I4, int64(v.(int32)))
+			case *int32:
+				vargs[n] = NewVariant(VT_I4|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*int32)))))
+			case uint32:
+				vargs[n] = NewVariant(VT_UI4, int64(v.(uint32)))
+			case *uint32:
+				vargs[n] = NewVariant(VT_UI4|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint32)))))
+			case int64:
+				vargs[n] = NewVariant(VT_I8, int64(v.(int64)))
+			case *int64:
+				vargs[n] = NewVariant(VT_I8|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*int64)))))
+			case uint64:
+				vargs[n] = NewVariant(VT_UI8, int64(uintptr(v.(uint64))))
+			case *uint64:
+				vargs[n] = NewVariant(VT_UI8|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint64)))))
+			case int:
+				vargs[n] = NewVariant(VT_I4, int64(v.(int)))
+			case *int:
+				vargs[n] = NewVariant(VT_I4|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*int)))))
+			case uint:
+				vargs[n] = NewVariant(VT_UI4, int64(v.(uint)))
+			case *uint:
+				vargs[n] = NewVariant(VT_UI4|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*uint)))))
+			case float32:
+				vargs[n] = NewVariant(VT_R4, *(*int64)(unsafe.Pointer(&vv)))
+			case *float32:
+				vargs[n] = NewVariant(VT_R4|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*float32)))))
+			case float64:
+				vargs[n] = NewVariant(VT_R8, *(*int64)(unsafe.Pointer(&vv)))
+			case *float64:
+				vargs[n] = NewVariant(VT_R8|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*float64)))))
+			case *big.Int:
+				vargs[n] = NewVariant(VT_DECIMAL, v.(*big.Int).Int64())
+			case string:
+				vargs[n] = NewVariant(VT_BSTR, int64(uintptr(unsafe.Pointer(SysAllocStringLen(v.(string))))))
+			case *string:
+				vargs[n] = NewVariant(VT_BSTR|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*string)))))
+			case time.Time:
+				s := vv.Format("2006-01-02 15:04:05")
+				vargs[n] = NewVariant(VT_BSTR, int64(uintptr(unsafe.Pointer(SysAllocStringLen(s)))))
+			case *time.Time:
+				s := vv.Format("2006-01-02 15:04:05")
+				vargs[n] = NewVariant(VT_BSTR|VT_BYREF, int64(uintptr(unsafe.Pointer(&s))))
+			case *IDispatch:
+				vargs[n] = NewVariant(VT_DISPATCH, int64(uintptr(unsafe.Pointer(v.(*IDispatch)))))
+			case **IDispatch:
+				vargs[n] = NewVariant(VT_DISPATCH|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(**IDispatch)))))
+			case nil:
+				vargs[n] = NewVariant(VT_NULL, 0)
+			case *VARIANT:
+				vargs[n] = NewVariant(VT_VARIANT|VT_BYREF, int64(uintptr(unsafe.Pointer(v.(*VARIANT)))))
+			case []byte:
+				safeByteArray := safeArrayFromByteSlice(v.([]byte))
+				vargs[n] = NewVariant(VT_ARRAY|VT_UI1, int64(uintptr(unsafe.Pointer(safeByteArray))))
+				defer VariantClear(&vargs[n])
+			case []string:
+				safeByteArray := safeArrayFromStringSlice(v.([]string))
+				vargs[n] = NewVariant(VT_ARRAY|VT_BSTR, int64(uintptr(unsafe.Pointer(safeByteArray))))
+				defer VariantClear(&vargs[n])
+			default:
+				panic("unknown type")
+			}
+		}
+		dispparams.rgvarg = uintptr(unsafe.Pointer(&vargs[0]))
+		dispparams.cArgs = uint32(len(params))
+	}
+
+	result = new(VARIANT)
+	var excepInfo EXCEPINFO
+	VariantInit(result)
+	hr, _, _ := syscall.Syscall9(
+		disp.VTable().Invoke,
+		9,
+		uintptr(unsafe.Pointer(disp)),
+		uintptr(dispid),
+		uintptr(unsafe.Pointer(IID_NULL)),
+		uintptr(GetUserDefaultLCID()),
+		uintptr(dispatch),
+		uintptr(unsafe.Pointer(&dispparams)),
+		uintptr(unsafe.Pointer(result)),
+		uintptr(unsafe.Pointer(&excepInfo)),
+		0)
+	if hr != 0 {
+		err = NewErrorWithSubError(hr, BstrToString(excepInfo.bstrDescription), excepInfo)
+	}
+	for i, varg := range vargs {
+		n := len(params) - i - 1
+		if varg.VT == VT_BSTR && varg.Val != 0 {
+			SysFreeString(((*int16)(unsafe.Pointer(uintptr(varg.Val)))))
+		}
+		if varg.VT == (VT_BSTR|VT_BYREF) && varg.Val != 0 {
+			*(params[n].(*string)) = LpOleStrToString(*(**uint16)(unsafe.Pointer(uintptr(varg.Val))))
+		}
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/ienumvariant.go

@@ -0,0 +1,19 @@
+package ole
+
+import "unsafe"
+
+type IEnumVARIANT struct {
+	IUnknown
+}
+
+type IEnumVARIANTVtbl struct {
+	IUnknownVtbl
+	Next  uintptr
+	Skip  uintptr
+	Reset uintptr
+	Clone uintptr
+}
+
+func (v *IEnumVARIANT) VTable() *IEnumVARIANTVtbl {
+	return (*IEnumVARIANTVtbl)(unsafe.Pointer(v.RawVTable))
+}

vendor/github.com/go-ole/go-ole/ienumvariant_func.go

@@ -0,0 +1,19 @@
+// +build !windows
+
+package ole
+
+func (enum *IEnumVARIANT) Clone() (*IEnumVARIANT, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+func (enum *IEnumVARIANT) Reset() error {
+	return NewError(E_NOTIMPL)
+}
+
+func (enum *IEnumVARIANT) Skip(celt uint) error {
+	return NewError(E_NOTIMPL)
+}
+
+func (enum *IEnumVARIANT) Next(celt uint) (VARIANT, uint, error) {
+	return NewVariant(VT_NULL, int64(0)), 0, NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/ienumvariant_windows.go

@@ -0,0 +1,63 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func (enum *IEnumVARIANT) Clone() (cloned *IEnumVARIANT, err error) {
+	hr, _, _ := syscall.Syscall(
+		enum.VTable().Clone,
+		2,
+		uintptr(unsafe.Pointer(enum)),
+		uintptr(unsafe.Pointer(&cloned)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func (enum *IEnumVARIANT) Reset() (err error) {
+	hr, _, _ := syscall.Syscall(
+		enum.VTable().Reset,
+		1,
+		uintptr(unsafe.Pointer(enum)),
+		0,
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func (enum *IEnumVARIANT) Skip(celt uint) (err error) {
+	hr, _, _ := syscall.Syscall(
+		enum.VTable().Skip,
+		2,
+		uintptr(unsafe.Pointer(enum)),
+		uintptr(celt),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func (enum *IEnumVARIANT) Next(celt uint) (array VARIANT, length uint, err error) {
+	hr, _, _ := syscall.Syscall6(
+		enum.VTable().Next,
+		4,
+		uintptr(unsafe.Pointer(enum)),
+		uintptr(celt),
+		uintptr(unsafe.Pointer(&array)),
+		uintptr(unsafe.Pointer(&length)),
+		0,
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/iinspectable.go

@@ -0,0 +1,18 @@
+package ole
+
+import "unsafe"
+
+type IInspectable struct {
+	IUnknown
+}
+
+type IInspectableVtbl struct {
+	IUnknownVtbl
+	GetIIds             uintptr
+	GetRuntimeClassName uintptr
+	GetTrustLevel       uintptr
+}
+
+func (v *IInspectable) VTable() *IInspectableVtbl {
+	return (*IInspectableVtbl)(unsafe.Pointer(v.RawVTable))
+}

vendor/github.com/go-ole/go-ole/iinspectable_func.go

@@ -0,0 +1,15 @@
+// +build !windows
+
+package ole
+
+func (v *IInspectable) GetIids() ([]*GUID, error) {
+	return []*GUID{}, NewError(E_NOTIMPL)
+}
+
+func (v *IInspectable) GetRuntimeClassName() (string, error) {
+	return "", NewError(E_NOTIMPL)
+}
+
+func (v *IInspectable) GetTrustLevel() (uint32, error) {
+	return uint32(0), NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/iinspectable_windows.go

@@ -0,0 +1,72 @@
+// +build windows
+
+package ole
+
+import (
+	"bytes"
+	"encoding/binary"
+	"reflect"
+	"syscall"
+	"unsafe"
+)
+
+func (v *IInspectable) GetIids() (iids []*GUID, err error) {
+	var count uint32
+	var array uintptr
+	hr, _, _ := syscall.Syscall(
+		v.VTable().GetIIds,
+		3,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(&count)),
+		uintptr(unsafe.Pointer(&array)))
+	if hr != 0 {
+		err = NewError(hr)
+		return
+	}
+	defer CoTaskMemFree(array)
+
+	iids = make([]*GUID, count)
+	byteCount := count * uint32(unsafe.Sizeof(GUID{}))
+	slicehdr := reflect.SliceHeader{Data: array, Len: int(byteCount), Cap: int(byteCount)}
+	byteSlice := *(*[]byte)(unsafe.Pointer(&slicehdr))
+	reader := bytes.NewReader(byteSlice)
+	for i := range iids {
+		guid := GUID{}
+		err = binary.Read(reader, binary.LittleEndian, &guid)
+		if err != nil {
+			return
+		}
+		iids[i] = &guid
+	}
+	return
+}
+
+func (v *IInspectable) GetRuntimeClassName() (s string, err error) {
+	var hstring HString
+	hr, _, _ := syscall.Syscall(
+		v.VTable().GetRuntimeClassName,
+		2,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(&hstring)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+		return
+	}
+	s = hstring.String()
+	DeleteHString(hstring)
+	return
+}
+
+func (v *IInspectable) GetTrustLevel() (level uint32, err error) {
+	hr, _, _ := syscall.Syscall(
+		v.VTable().GetTrustLevel,
+		2,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(&level)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/iprovideclassinfo.go

@@ -0,0 +1,21 @@
+package ole
+
+import "unsafe"
+
+type IProvideClassInfo struct {
+	IUnknown
+}
+
+type IProvideClassInfoVtbl struct {
+	IUnknownVtbl
+	GetClassInfo uintptr
+}
+
+func (v *IProvideClassInfo) VTable() *IProvideClassInfoVtbl {
+	return (*IProvideClassInfoVtbl)(unsafe.Pointer(v.RawVTable))
+}
+
+func (v *IProvideClassInfo) GetClassInfo() (cinfo *ITypeInfo, err error) {
+	cinfo, err = getClassInfo(v)
+	return
+}

vendor/github.com/go-ole/go-ole/iprovideclassinfo_func.go

@@ -0,0 +1,7 @@
+// +build !windows
+
+package ole
+
+func getClassInfo(disp *IProvideClassInfo) (tinfo *ITypeInfo, err error) {
+	return nil, NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/iprovideclassinfo_windows.go

@@ -0,0 +1,21 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func getClassInfo(disp *IProvideClassInfo) (tinfo *ITypeInfo, err error) {
+	hr, _, _ := syscall.Syscall(
+		disp.VTable().GetClassInfo,
+		2,
+		uintptr(unsafe.Pointer(disp)),
+		uintptr(unsafe.Pointer(&tinfo)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/itypeinfo.go

@@ -0,0 +1,34 @@
+package ole
+
+import "unsafe"
+
+type ITypeInfo struct {
+	IUnknown
+}
+
+type ITypeInfoVtbl struct {
+	IUnknownVtbl
+	GetTypeAttr          uintptr
+	GetTypeComp          uintptr
+	GetFuncDesc          uintptr
+	GetVarDesc           uintptr
+	GetNames             uintptr
+	GetRefTypeOfImplType uintptr
+	GetImplTypeFlags     uintptr
+	GetIDsOfNames        uintptr
+	Invoke               uintptr
+	GetDocumentation     uintptr
+	GetDllEntry          uintptr
+	GetRefTypeInfo       uintptr
+	AddressOfMember      uintptr
+	CreateInstance       uintptr
+	GetMops              uintptr
+	GetContainingTypeLib uintptr
+	ReleaseTypeAttr      uintptr
+	ReleaseFuncDesc      uintptr
+	ReleaseVarDesc       uintptr
+}
+
+func (v *ITypeInfo) VTable() *ITypeInfoVtbl {
+	return (*ITypeInfoVtbl)(unsafe.Pointer(v.RawVTable))
+}

vendor/github.com/go-ole/go-ole/itypeinfo_func.go

@@ -0,0 +1,7 @@
+// +build !windows
+
+package ole
+
+func (v *ITypeInfo) GetTypeAttr() (*TYPEATTR, error) {
+	return nil, NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/itypeinfo_windows.go

@@ -0,0 +1,21 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func (v *ITypeInfo) GetTypeAttr() (tattr *TYPEATTR, err error) {
+	hr, _, _ := syscall.Syscall(
+		uintptr(v.VTable().GetTypeAttr),
+		2,
+		uintptr(unsafe.Pointer(v)),
+		uintptr(unsafe.Pointer(&tattr)),
+		0)
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/iunknown.go

@@ -0,0 +1,57 @@
+package ole
+
+import "unsafe"
+
+type IUnknown struct {
+	RawVTable *interface{}
+}
+
+type IUnknownVtbl struct {
+	QueryInterface uintptr
+	AddRef         uintptr
+	Release        uintptr
+}
+
+type UnknownLike interface {
+	QueryInterface(iid *GUID) (disp *IDispatch, err error)
+	AddRef() int32
+	Release() int32
+}
+
+func (v *IUnknown) VTable() *IUnknownVtbl {
+	return (*IUnknownVtbl)(unsafe.Pointer(v.RawVTable))
+}
+
+func (v *IUnknown) PutQueryInterface(interfaceID *GUID, obj interface{}) error {
+	return reflectQueryInterface(v, v.VTable().QueryInterface, interfaceID, obj)
+}
+
+func (v *IUnknown) IDispatch(interfaceID *GUID) (dispatch *IDispatch, err error) {
+	err = v.PutQueryInterface(interfaceID, &dispatch)
+	return
+}
+
+func (v *IUnknown) IEnumVARIANT(interfaceID *GUID) (enum *IEnumVARIANT, err error) {
+	err = v.PutQueryInterface(interfaceID, &enum)
+	return
+}
+
+func (v *IUnknown) QueryInterface(iid *GUID) (*IDispatch, error) {
+	return queryInterface(v, iid)
+}
+
+func (v *IUnknown) MustQueryInterface(iid *GUID) (disp *IDispatch) {
+	unk, err := queryInterface(v, iid)
+	if err != nil {
+		panic(err)
+	}
+	return unk
+}
+
+func (v *IUnknown) AddRef() int32 {
+	return addRef(v)
+}
+
+func (v *IUnknown) Release() int32 {
+	return release(v)
+}

vendor/github.com/go-ole/go-ole/iunknown_func.go

@@ -0,0 +1,19 @@
+// +build !windows
+
+package ole
+
+func reflectQueryInterface(self interface{}, method uintptr, interfaceID *GUID, obj interface{}) (err error) {
+	return NewError(E_NOTIMPL)
+}
+
+func queryInterface(unk *IUnknown, iid *GUID) (disp *IDispatch, err error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+func addRef(unk *IUnknown) int32 {
+	return 0
+}
+
+func release(unk *IUnknown) int32 {
+	return 0
+}

vendor/github.com/go-ole/go-ole/iunknown_windows.go

@@ -0,0 +1,58 @@
+// +build windows
+
+package ole
+
+import (
+	"reflect"
+	"syscall"
+	"unsafe"
+)
+
+func reflectQueryInterface(self interface{}, method uintptr, interfaceID *GUID, obj interface{}) (err error) {
+	selfValue := reflect.ValueOf(self).Elem()
+	objValue := reflect.ValueOf(obj).Elem()
+
+	hr, _, _ := syscall.Syscall(
+		method,
+		3,
+		selfValue.UnsafeAddr(),
+		uintptr(unsafe.Pointer(interfaceID)),
+		objValue.Addr().Pointer())
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func queryInterface(unk *IUnknown, iid *GUID) (disp *IDispatch, err error) {
+	hr, _, _ := syscall.Syscall(
+		unk.VTable().QueryInterface,
+		3,
+		uintptr(unsafe.Pointer(unk)),
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(&disp)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func addRef(unk *IUnknown) int32 {
+	ret, _, _ := syscall.Syscall(
+		unk.VTable().AddRef,
+		1,
+		uintptr(unsafe.Pointer(unk)),
+		0,
+		0)
+	return int32(ret)
+}
+
+func release(unk *IUnknown) int32 {
+	ret, _, _ := syscall.Syscall(
+		unk.VTable().Release,
+		1,
+		uintptr(unsafe.Pointer(unk)),
+		0,
+		0)
+	return int32(ret)
+}

vendor/github.com/go-ole/go-ole/ole.go

@@ -0,0 +1,157 @@
+package ole
+
+import (
+	"fmt"
+	"strings"
+)
+
+// DISPPARAMS are the arguments that passed to methods or property.
+type DISPPARAMS struct {
+	rgvarg            uintptr
+	rgdispidNamedArgs uintptr
+	cArgs             uint32
+	cNamedArgs        uint32
+}
+
+// EXCEPINFO defines exception info.
+type EXCEPINFO struct {
+	wCode             uint16
+	wReserved         uint16
+	bstrSource        *uint16
+	bstrDescription   *uint16
+	bstrHelpFile      *uint16
+	dwHelpContext     uint32
+	pvReserved        uintptr
+	pfnDeferredFillIn uintptr
+	scode             uint32
+}
+
+// WCode return wCode in EXCEPINFO.
+func (e EXCEPINFO) WCode() uint16 {
+	return e.wCode
+}
+
+// SCODE return scode in EXCEPINFO.
+func (e EXCEPINFO) SCODE() uint32 {
+	return e.scode
+}
+
+// String convert EXCEPINFO to string.
+func (e EXCEPINFO) String() string {
+	var src, desc, hlp string
+	if e.bstrSource == nil {
+		src = "<nil>"
+	} else {
+		src = BstrToString(e.bstrSource)
+	}
+
+	if e.bstrDescription == nil {
+		desc = "<nil>"
+	} else {
+		desc = BstrToString(e.bstrDescription)
+	}
+
+	if e.bstrHelpFile == nil {
+		hlp = "<nil>"
+	} else {
+		hlp = BstrToString(e.bstrHelpFile)
+	}
+
+	return fmt.Sprintf(
+		"wCode: %#x, bstrSource: %v, bstrDescription: %v, bstrHelpFile: %v, dwHelpContext: %#x, scode: %#x",
+		e.wCode, src, desc, hlp, e.dwHelpContext, e.scode,
+	)
+}
+
+// Error implements error interface and returns error string.
+func (e EXCEPINFO) Error() string {
+	if e.bstrDescription != nil {
+		return strings.TrimSpace(BstrToString(e.bstrDescription))
+	}
+
+	src := "Unknown"
+	if e.bstrSource != nil {
+		src = BstrToString(e.bstrSource)
+	}
+
+	code := e.scode
+	if e.wCode != 0 {
+		code = uint32(e.wCode)
+	}
+
+	return fmt.Sprintf("%v: %#x", src, code)
+}
+
+// PARAMDATA defines parameter data type.
+type PARAMDATA struct {
+	Name *int16
+	Vt   uint16
+}
+
+// METHODDATA defines method info.
+type METHODDATA struct {
+	Name     *uint16
+	Data     *PARAMDATA
+	Dispid   int32
+	Meth     uint32
+	CC       int32
+	CArgs    uint32
+	Flags    uint16
+	VtReturn uint32
+}
+
+// INTERFACEDATA defines interface info.
+type INTERFACEDATA struct {
+	MethodData *METHODDATA
+	CMembers   uint32
+}
+
+// Point is 2D vector type.
+type Point struct {
+	X int32
+	Y int32
+}
+
+// Msg is message between processes.
+type Msg struct {
+	Hwnd    uint32
+	Message uint32
+	Wparam  int32
+	Lparam  int32
+	Time    uint32
+	Pt      Point
+}
+
+// TYPEDESC defines data type.
+type TYPEDESC struct {
+	Hreftype uint32
+	VT       uint16
+}
+
+// IDLDESC defines IDL info.
+type IDLDESC struct {
+	DwReserved uint32
+	WIDLFlags  uint16
+}
+
+// TYPEATTR defines type info.
+type TYPEATTR struct {
+	Guid             GUID
+	Lcid             uint32
+	dwReserved       uint32
+	MemidConstructor int32
+	MemidDestructor  int32
+	LpstrSchema      *uint16
+	CbSizeInstance   uint32
+	Typekind         int32
+	CFuncs           uint16
+	CVars            uint16
+	CImplTypes       uint16
+	CbSizeVft        uint16
+	CbAlignment      uint16
+	WTypeFlags       uint16
+	WMajorVerNum     uint16
+	WMinorVerNum     uint16
+	TdescAlias       TYPEDESC
+	IdldescType      IDLDESC
+}

vendor/github.com/go-ole/go-ole/oleutil/connection.go

@@ -0,0 +1,100 @@
+// +build windows
+
+package oleutil
+
+import (
+	"reflect"
+	"unsafe"
+
+	ole "github.com/go-ole/go-ole"
+)
+
+type stdDispatch struct {
+	lpVtbl  *stdDispatchVtbl
+	ref     int32
+	iid     *ole.GUID
+	iface   interface{}
+	funcMap map[string]int32
+}
+
+type stdDispatchVtbl struct {
+	pQueryInterface   uintptr
+	pAddRef           uintptr
+	pRelease          uintptr
+	pGetTypeInfoCount uintptr
+	pGetTypeInfo      uintptr
+	pGetIDsOfNames    uintptr
+	pInvoke           uintptr
+}
+
+func dispQueryInterface(this *ole.IUnknown, iid *ole.GUID, punk **ole.IUnknown) uint32 {
+	pthis := (*stdDispatch)(unsafe.Pointer(this))
+	*punk = nil
+	if ole.IsEqualGUID(iid, ole.IID_IUnknown) ||
+		ole.IsEqualGUID(iid, ole.IID_IDispatch) {
+		dispAddRef(this)
+		*punk = this
+		return ole.S_OK
+	}
+	if ole.IsEqualGUID(iid, pthis.iid) {
+		dispAddRef(this)
+		*punk = this
+		return ole.S_OK
+	}
+	return ole.E_NOINTERFACE
+}
+
+func dispAddRef(this *ole.IUnknown) int32 {
+	pthis := (*stdDispatch)(unsafe.Pointer(this))
+	pthis.ref++
+	return pthis.ref
+}
+
+func dispRelease(this *ole.IUnknown) int32 {
+	pthis := (*stdDispatch)(unsafe.Pointer(this))
+	pthis.ref--
+	return pthis.ref
+}
+
+func dispGetIDsOfNames(this *ole.IUnknown, iid *ole.GUID, wnames []*uint16, namelen int, lcid int, pdisp []int32) uintptr {
+	pthis := (*stdDispatch)(unsafe.Pointer(this))
+	names := make([]string, len(wnames))
+	for i := 0; i < len(names); i++ {
+		names[i] = ole.LpOleStrToString(wnames[i])
+	}
+	for n := 0; n < namelen; n++ {
+		if id, ok := pthis.funcMap[names[n]]; ok {
+			pdisp[n] = id
+		}
+	}
+	return ole.S_OK
+}
+
+func dispGetTypeInfoCount(pcount *int) uintptr {
+	if pcount != nil {
+		*pcount = 0
+	}
+	return ole.S_OK
+}
+
+func dispGetTypeInfo(ptypeif *uintptr) uintptr {
+	return ole.E_NOTIMPL
+}
+
+func dispInvoke(this *ole.IDispatch, dispid int32, riid *ole.GUID, lcid int, flags int16, dispparams *ole.DISPPARAMS, result *ole.VARIANT, pexcepinfo *ole.EXCEPINFO, nerr *uint) uintptr {
+	pthis := (*stdDispatch)(unsafe.Pointer(this))
+	found := ""
+	for name, id := range pthis.funcMap {
+		if id == dispid {
+			found = name
+		}
+	}
+	if found != "" {
+		rv := reflect.ValueOf(pthis.iface).Elem()
+		rm := rv.MethodByName(found)
+		rr := rm.Call([]reflect.Value{})
+		println(len(rr))
+		return ole.S_OK
+	}
+	return ole.E_NOTIMPL
+}

vendor/github.com/go-ole/go-ole/oleutil/connection_func.go

@@ -0,0 +1,10 @@
+// +build !windows
+
+package oleutil
+
+import ole "github.com/go-ole/go-ole"
+
+// ConnectObject creates a connection point between two services for communication.
+func ConnectObject(disp *ole.IDispatch, iid *ole.GUID, idisp interface{}) (uint32, error) {
+	return 0, ole.NewError(ole.E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/oleutil/connection_windows.go

@@ -0,0 +1,58 @@
+// +build windows
+
+package oleutil
+
+import (
+	"reflect"
+	"syscall"
+	"unsafe"
+
+	ole "github.com/go-ole/go-ole"
+)
+
+// ConnectObject creates a connection point between two services for communication.
+func ConnectObject(disp *ole.IDispatch, iid *ole.GUID, idisp interface{}) (cookie uint32, err error) {
+	unknown, err := disp.QueryInterface(ole.IID_IConnectionPointContainer)
+	if err != nil {
+		return
+	}
+
+	container := (*ole.IConnectionPointContainer)(unsafe.Pointer(unknown))
+	var point *ole.IConnectionPoint
+	err = container.FindConnectionPoint(iid, &point)
+	if err != nil {
+		return
+	}
+	if edisp, ok := idisp.(*ole.IUnknown); ok {
+		cookie, err = point.Advise(edisp)
+		container.Release()
+		if err != nil {
+			return
+		}
+	}
+	rv := reflect.ValueOf(disp).Elem()
+	if rv.Type().Kind() == reflect.Struct {
+		dest := &stdDispatch{}
+		dest.lpVtbl = &stdDispatchVtbl{}
+		dest.lpVtbl.pQueryInterface = syscall.NewCallback(dispQueryInterface)
+		dest.lpVtbl.pAddRef = syscall.NewCallback(dispAddRef)
+		dest.lpVtbl.pRelease = syscall.NewCallback(dispRelease)
+		dest.lpVtbl.pGetTypeInfoCount = syscall.NewCallback(dispGetTypeInfoCount)
+		dest.lpVtbl.pGetTypeInfo = syscall.NewCallback(dispGetTypeInfo)
+		dest.lpVtbl.pGetIDsOfNames = syscall.NewCallback(dispGetIDsOfNames)
+		dest.lpVtbl.pInvoke = syscall.NewCallback(dispInvoke)
+		dest.iface = disp
+		dest.iid = iid
+		cookie, err = point.Advise((*ole.IUnknown)(unsafe.Pointer(dest)))
+		container.Release()
+		if err != nil {
+			point.Release()
+			return
+		}
+		return
+	}
+
+	container.Release()
+
+	return 0, ole.NewError(ole.E_INVALIDARG)
+}

vendor/github.com/go-ole/go-ole/oleutil/go-get.go

@@ -0,0 +1,6 @@
+// This file is here so go get succeeds as without it errors with:
+// no buildable Go source files in ...
+//
+// +build !windows
+
+package oleutil

vendor/github.com/go-ole/go-ole/oleutil/oleutil.go

@@ -0,0 +1,127 @@
+package oleutil
+
+import ole "github.com/go-ole/go-ole"
+
+// ClassIDFrom retrieves class ID whether given is program ID or application string.
+func ClassIDFrom(programID string) (classID *ole.GUID, err error) {
+	return ole.ClassIDFrom(programID)
+}
+
+// CreateObject creates object from programID based on interface type.
+//
+// Only supports IUnknown.
+//
+// Program ID can be either program ID or application string.
+func CreateObject(programID string) (unknown *ole.IUnknown, err error) {
+	classID, err := ole.ClassIDFrom(programID)
+	if err != nil {
+		return
+	}
+
+	unknown, err = ole.CreateInstance(classID, ole.IID_IUnknown)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// GetActiveObject retrieves active object for program ID and interface ID based
+// on interface type.
+//
+// Only supports IUnknown.
+//
+// Program ID can be either program ID or application string.
+func GetActiveObject(programID string) (unknown *ole.IUnknown, err error) {
+	classID, err := ole.ClassIDFrom(programID)
+	if err != nil {
+		return
+	}
+
+	unknown, err = ole.GetActiveObject(classID, ole.IID_IUnknown)
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+// CallMethod calls method on IDispatch with parameters.
+func CallMethod(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT, err error) {
+	return disp.InvokeWithOptionalArgs(name, ole.DISPATCH_METHOD, params)
+}
+
+// MustCallMethod calls method on IDispatch with parameters or panics.
+func MustCallMethod(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT) {
+	r, err := CallMethod(disp, name, params...)
+	if err != nil {
+		panic(err.Error())
+	}
+	return r
+}
+
+// GetProperty retrieves property from IDispatch.
+func GetProperty(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT, err error) {
+	return disp.InvokeWithOptionalArgs(name, ole.DISPATCH_PROPERTYGET, params)
+}
+
+// MustGetProperty retrieves property from IDispatch or panics.
+func MustGetProperty(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT) {
+	r, err := GetProperty(disp, name, params...)
+	if err != nil {
+		panic(err.Error())
+	}
+	return r
+}
+
+// PutProperty mutates property.
+func PutProperty(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT, err error) {
+	return disp.InvokeWithOptionalArgs(name, ole.DISPATCH_PROPERTYPUT, params)
+}
+
+// MustPutProperty mutates property or panics.
+func MustPutProperty(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT) {
+	r, err := PutProperty(disp, name, params...)
+	if err != nil {
+		panic(err.Error())
+	}
+	return r
+}
+
+// PutPropertyRef mutates property reference.
+func PutPropertyRef(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT, err error) {
+	return disp.InvokeWithOptionalArgs(name, ole.DISPATCH_PROPERTYPUTREF, params)
+}
+
+// MustPutPropertyRef mutates property reference or panics.
+func MustPutPropertyRef(disp *ole.IDispatch, name string, params ...interface{}) (result *ole.VARIANT) {
+	r, err := PutPropertyRef(disp, name, params...)
+	if err != nil {
+		panic(err.Error())
+	}
+	return r
+}
+
+func ForEach(disp *ole.IDispatch, f func(v *ole.VARIANT) error) error {
+	newEnum, err := disp.GetProperty("_NewEnum")
+	if err != nil {
+		return err
+	}
+	defer newEnum.Clear()
+
+	enum, err := newEnum.ToIUnknown().IEnumVARIANT(ole.IID_IEnumVariant)
+	if err != nil {
+		return err
+	}
+	defer enum.Release()
+
+	for item, length, err := enum.Next(1); length > 0; item, length, err = enum.Next(1) {
+		if err != nil {
+			return err
+		}
+		if ferr := f(&item); ferr != nil {
+			return ferr
+		}
+	}
+	return nil
+}

vendor/github.com/go-ole/go-ole/safearray.go

@@ -0,0 +1,27 @@
+// Package is meant to retrieve and process safe array data returned from COM.
+
+package ole
+
+// SafeArrayBound defines the SafeArray boundaries.
+type SafeArrayBound struct {
+	Elements   uint32
+	LowerBound int32
+}
+
+// SafeArray is how COM handles arrays.
+type SafeArray struct {
+	Dimensions   uint16
+	FeaturesFlag uint16
+	ElementsSize uint32
+	LocksAmount  uint32
+	Data         uint32
+	Bounds       [16]byte
+}
+
+// SAFEARRAY is obsolete, exists for backwards compatibility.
+// Use SafeArray
+type SAFEARRAY SafeArray
+
+// SAFEARRAYBOUND is obsolete, exists for backwards compatibility.
+// Use SafeArrayBound
+type SAFEARRAYBOUND SafeArrayBound

vendor/github.com/go-ole/go-ole/safearray_func.go

@@ -0,0 +1,211 @@
+// +build !windows
+
+package ole
+
+import (
+	"unsafe"
+)
+
+// safeArrayAccessData returns raw array pointer.
+//
+// AKA: SafeArrayAccessData in Windows API.
+func safeArrayAccessData(safearray *SafeArray) (uintptr, error) {
+	return uintptr(0), NewError(E_NOTIMPL)
+}
+
+// safeArrayUnaccessData releases raw array.
+//
+// AKA: SafeArrayUnaccessData in Windows API.
+func safeArrayUnaccessData(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayAllocData allocates SafeArray.
+//
+// AKA: SafeArrayAllocData in Windows API.
+func safeArrayAllocData(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayAllocDescriptor allocates SafeArray.
+//
+// AKA: SafeArrayAllocDescriptor in Windows API.
+func safeArrayAllocDescriptor(dimensions uint32) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayAllocDescriptorEx allocates SafeArray.
+//
+// AKA: SafeArrayAllocDescriptorEx in Windows API.
+func safeArrayAllocDescriptorEx(variantType VT, dimensions uint32) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayCopy returns copy of SafeArray.
+//
+// AKA: SafeArrayCopy in Windows API.
+func safeArrayCopy(original *SafeArray) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayCopyData duplicates SafeArray into another SafeArray object.
+//
+// AKA: SafeArrayCopyData in Windows API.
+func safeArrayCopyData(original *SafeArray, duplicate *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayCreate creates SafeArray.
+//
+// AKA: SafeArrayCreate in Windows API.
+func safeArrayCreate(variantType VT, dimensions uint32, bounds *SafeArrayBound) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayCreateEx creates SafeArray.
+//
+// AKA: SafeArrayCreateEx in Windows API.
+func safeArrayCreateEx(variantType VT, dimensions uint32, bounds *SafeArrayBound, extra uintptr) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayCreateVector creates SafeArray.
+//
+// AKA: SafeArrayCreateVector in Windows API.
+func safeArrayCreateVector(variantType VT, lowerBound int32, length uint32) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayCreateVectorEx creates SafeArray.
+//
+// AKA: SafeArrayCreateVectorEx in Windows API.
+func safeArrayCreateVectorEx(variantType VT, lowerBound int32, length uint32, extra uintptr) (*SafeArray, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayDestroy destroys SafeArray object.
+//
+// AKA: SafeArrayDestroy in Windows API.
+func safeArrayDestroy(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayDestroyData destroys SafeArray object.
+//
+// AKA: SafeArrayDestroyData in Windows API.
+func safeArrayDestroyData(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayDestroyDescriptor destroys SafeArray object.
+//
+// AKA: SafeArrayDestroyDescriptor in Windows API.
+func safeArrayDestroyDescriptor(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayGetDim is the amount of dimensions in the SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetDim in Windows API.
+func safeArrayGetDim(safearray *SafeArray) (*uint32, error) {
+	u := uint32(0)
+	return &u, NewError(E_NOTIMPL)
+}
+
+// safeArrayGetElementSize is the element size in bytes.
+//
+// AKA: SafeArrayGetElemsize in Windows API.
+func safeArrayGetElementSize(safearray *SafeArray) (*uint32, error) {
+	u := uint32(0)
+	return &u, NewError(E_NOTIMPL)
+}
+
+// safeArrayGetElement retrieves element at given index.
+func safeArrayGetElement(safearray *SafeArray, index int32, pv unsafe.Pointer) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayGetElement retrieves element at given index and converts to string.
+func safeArrayGetElementString(safearray *SafeArray, index int32) (string, error) {
+	return "", NewError(E_NOTIMPL)
+}
+
+// safeArrayGetIID is the InterfaceID of the elements in the SafeArray.
+//
+// AKA: SafeArrayGetIID in Windows API.
+func safeArrayGetIID(safearray *SafeArray) (*GUID, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArrayGetLBound returns lower bounds of SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetLBound in Windows API.
+func safeArrayGetLBound(safearray *SafeArray, dimension uint32) (int32, error) {
+	return int32(0), NewError(E_NOTIMPL)
+}
+
+// safeArrayGetUBound returns upper bounds of SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetUBound in Windows API.
+func safeArrayGetUBound(safearray *SafeArray, dimension uint32) (int32, error) {
+	return int32(0), NewError(E_NOTIMPL)
+}
+
+// safeArrayGetVartype returns data type of SafeArray.
+//
+// AKA: SafeArrayGetVartype in Windows API.
+func safeArrayGetVartype(safearray *SafeArray) (uint16, error) {
+	return uint16(0), NewError(E_NOTIMPL)
+}
+
+// safeArrayLock locks SafeArray for reading to modify SafeArray.
+//
+// This must be called during some calls to ensure that another process does not
+// read or write to the SafeArray during editing.
+//
+// AKA: SafeArrayLock in Windows API.
+func safeArrayLock(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayUnlock unlocks SafeArray for reading.
+//
+// AKA: SafeArrayUnlock in Windows API.
+func safeArrayUnlock(safearray *SafeArray) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayPutElement stores the data element at the specified location in the
+// array.
+//
+// AKA: SafeArrayPutElement in Windows API.
+func safeArrayPutElement(safearray *SafeArray, index int64, element uintptr) error {
+	return NewError(E_NOTIMPL)
+}
+
+// safeArrayGetRecordInfo accesses IRecordInfo info for custom types.
+//
+// AKA: SafeArrayGetRecordInfo in Windows API.
+//
+// XXX: Must implement IRecordInfo interface for this to return.
+func safeArrayGetRecordInfo(safearray *SafeArray) (interface{}, error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// safeArraySetRecordInfo mutates IRecordInfo info for custom types.
+//
+// AKA: SafeArraySetRecordInfo in Windows API.
+//
+// XXX: Must implement IRecordInfo interface for this to return.
+func safeArraySetRecordInfo(safearray *SafeArray, recordInfo interface{}) error {
+	return NewError(E_NOTIMPL)
+}

vendor/github.com/go-ole/go-ole/safearray_windows.go

@@ -0,0 +1,337 @@
+// +build windows
+
+package ole
+
+import (
+	"unsafe"
+)
+
+var (
+	procSafeArrayAccessData, _        = modoleaut32.FindProc("SafeArrayAccessData")
+	procSafeArrayAllocData, _         = modoleaut32.FindProc("SafeArrayAllocData")
+	procSafeArrayAllocDescriptor, _   = modoleaut32.FindProc("SafeArrayAllocDescriptor")
+	procSafeArrayAllocDescriptorEx, _ = modoleaut32.FindProc("SafeArrayAllocDescriptorEx")
+	procSafeArrayCopy, _              = modoleaut32.FindProc("SafeArrayCopy")
+	procSafeArrayCopyData, _          = modoleaut32.FindProc("SafeArrayCopyData")
+	procSafeArrayCreate, _            = modoleaut32.FindProc("SafeArrayCreate")
+	procSafeArrayCreateEx, _          = modoleaut32.FindProc("SafeArrayCreateEx")
+	procSafeArrayCreateVector, _      = modoleaut32.FindProc("SafeArrayCreateVector")
+	procSafeArrayCreateVectorEx, _    = modoleaut32.FindProc("SafeArrayCreateVectorEx")
+	procSafeArrayDestroy, _           = modoleaut32.FindProc("SafeArrayDestroy")
+	procSafeArrayDestroyData, _       = modoleaut32.FindProc("SafeArrayDestroyData")
+	procSafeArrayDestroyDescriptor, _ = modoleaut32.FindProc("SafeArrayDestroyDescriptor")
+	procSafeArrayGetDim, _            = modoleaut32.FindProc("SafeArrayGetDim")
+	procSafeArrayGetElement, _        = modoleaut32.FindProc("SafeArrayGetElement")
+	procSafeArrayGetElemsize, _       = modoleaut32.FindProc("SafeArrayGetElemsize")
+	procSafeArrayGetIID, _            = modoleaut32.FindProc("SafeArrayGetIID")
+	procSafeArrayGetLBound, _         = modoleaut32.FindProc("SafeArrayGetLBound")
+	procSafeArrayGetUBound, _         = modoleaut32.FindProc("SafeArrayGetUBound")
+	procSafeArrayGetVartype, _        = modoleaut32.FindProc("SafeArrayGetVartype")
+	procSafeArrayLock, _              = modoleaut32.FindProc("SafeArrayLock")
+	procSafeArrayPtrOfIndex, _        = modoleaut32.FindProc("SafeArrayPtrOfIndex")
+	procSafeArrayUnaccessData, _      = modoleaut32.FindProc("SafeArrayUnaccessData")
+	procSafeArrayUnlock, _            = modoleaut32.FindProc("SafeArrayUnlock")
+	procSafeArrayPutElement, _        = modoleaut32.FindProc("SafeArrayPutElement")
+	//procSafeArrayRedim, _             = modoleaut32.FindProc("SafeArrayRedim") // TODO
+	//procSafeArraySetIID, _            = modoleaut32.FindProc("SafeArraySetIID") // TODO
+	procSafeArrayGetRecordInfo, _ = modoleaut32.FindProc("SafeArrayGetRecordInfo")
+	procSafeArraySetRecordInfo, _ = modoleaut32.FindProc("SafeArraySetRecordInfo")
+)
+
+// safeArrayAccessData returns raw array pointer.
+//
+// AKA: SafeArrayAccessData in Windows API.
+// Todo: Test
+func safeArrayAccessData(safearray *SafeArray) (element uintptr, err error) {
+	err = convertHresultToError(
+		procSafeArrayAccessData.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&element))))
+	return
+}
+
+// safeArrayUnaccessData releases raw array.
+//
+// AKA: SafeArrayUnaccessData in Windows API.
+func safeArrayUnaccessData(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayUnaccessData.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayAllocData allocates SafeArray.
+//
+// AKA: SafeArrayAllocData in Windows API.
+func safeArrayAllocData(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayAllocData.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayAllocDescriptor allocates SafeArray.
+//
+// AKA: SafeArrayAllocDescriptor in Windows API.
+func safeArrayAllocDescriptor(dimensions uint32) (safearray *SafeArray, err error) {
+	err = convertHresultToError(
+		procSafeArrayAllocDescriptor.Call(uintptr(dimensions), uintptr(unsafe.Pointer(&safearray))))
+	return
+}
+
+// safeArrayAllocDescriptorEx allocates SafeArray.
+//
+// AKA: SafeArrayAllocDescriptorEx in Windows API.
+func safeArrayAllocDescriptorEx(variantType VT, dimensions uint32) (safearray *SafeArray, err error) {
+	err = convertHresultToError(
+		procSafeArrayAllocDescriptorEx.Call(
+			uintptr(variantType),
+			uintptr(dimensions),
+			uintptr(unsafe.Pointer(&safearray))))
+	return
+}
+
+// safeArrayCopy returns copy of SafeArray.
+//
+// AKA: SafeArrayCopy in Windows API.
+func safeArrayCopy(original *SafeArray) (safearray *SafeArray, err error) {
+	err = convertHresultToError(
+		procSafeArrayCopy.Call(
+			uintptr(unsafe.Pointer(original)),
+			uintptr(unsafe.Pointer(&safearray))))
+	return
+}
+
+// safeArrayCopyData duplicates SafeArray into another SafeArray object.
+//
+// AKA: SafeArrayCopyData in Windows API.
+func safeArrayCopyData(original *SafeArray, duplicate *SafeArray) (err error) {
+	err = convertHresultToError(
+		procSafeArrayCopyData.Call(
+			uintptr(unsafe.Pointer(original)),
+			uintptr(unsafe.Pointer(duplicate))))
+	return
+}
+
+// safeArrayCreate creates SafeArray.
+//
+// AKA: SafeArrayCreate in Windows API.
+func safeArrayCreate(variantType VT, dimensions uint32, bounds *SafeArrayBound) (safearray *SafeArray, err error) {
+	sa, _, err := procSafeArrayCreate.Call(
+		uintptr(variantType),
+		uintptr(dimensions),
+		uintptr(unsafe.Pointer(bounds)))
+	safearray = (*SafeArray)(unsafe.Pointer(&sa))
+	return
+}
+
+// safeArrayCreateEx creates SafeArray.
+//
+// AKA: SafeArrayCreateEx in Windows API.
+func safeArrayCreateEx(variantType VT, dimensions uint32, bounds *SafeArrayBound, extra uintptr) (safearray *SafeArray, err error) {
+	sa, _, err := procSafeArrayCreateEx.Call(
+		uintptr(variantType),
+		uintptr(dimensions),
+		uintptr(unsafe.Pointer(bounds)),
+		extra)
+	safearray = (*SafeArray)(unsafe.Pointer(sa))
+	return
+}
+
+// safeArrayCreateVector creates SafeArray.
+//
+// AKA: SafeArrayCreateVector in Windows API.
+func safeArrayCreateVector(variantType VT, lowerBound int32, length uint32) (safearray *SafeArray, err error) {
+	sa, _, err := procSafeArrayCreateVector.Call(
+		uintptr(variantType),
+		uintptr(lowerBound),
+		uintptr(length))
+	safearray = (*SafeArray)(unsafe.Pointer(sa))
+	return
+}
+
+// safeArrayCreateVectorEx creates SafeArray.
+//
+// AKA: SafeArrayCreateVectorEx in Windows API.
+func safeArrayCreateVectorEx(variantType VT, lowerBound int32, length uint32, extra uintptr) (safearray *SafeArray, err error) {
+	sa, _, err := procSafeArrayCreateVectorEx.Call(
+		uintptr(variantType),
+		uintptr(lowerBound),
+		uintptr(length),
+		extra)
+	safearray = (*SafeArray)(unsafe.Pointer(sa))
+	return
+}
+
+// safeArrayDestroy destroys SafeArray object.
+//
+// AKA: SafeArrayDestroy in Windows API.
+func safeArrayDestroy(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayDestroy.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayDestroyData destroys SafeArray object.
+//
+// AKA: SafeArrayDestroyData in Windows API.
+func safeArrayDestroyData(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayDestroyData.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayDestroyDescriptor destroys SafeArray object.
+//
+// AKA: SafeArrayDestroyDescriptor in Windows API.
+func safeArrayDestroyDescriptor(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayDestroyDescriptor.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayGetDim is the amount of dimensions in the SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetDim in Windows API.
+func safeArrayGetDim(safearray *SafeArray) (dimensions *uint32, err error) {
+	l, _, err := procSafeArrayGetDim.Call(uintptr(unsafe.Pointer(safearray)))
+	dimensions = (*uint32)(unsafe.Pointer(l))
+	return
+}
+
+// safeArrayGetElementSize is the element size in bytes.
+//
+// AKA: SafeArrayGetElemsize in Windows API.
+func safeArrayGetElementSize(safearray *SafeArray) (length *uint32, err error) {
+	l, _, err := procSafeArrayGetElemsize.Call(uintptr(unsafe.Pointer(safearray)))
+	length = (*uint32)(unsafe.Pointer(l))
+	return
+}
+
+// safeArrayGetElement retrieves element at given index.
+func safeArrayGetElement(safearray *SafeArray, index int32, pv unsafe.Pointer) error {
+	return convertHresultToError(
+		procSafeArrayGetElement.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&index)),
+			uintptr(pv)))
+}
+
+// safeArrayGetElementString retrieves element at given index and converts to string.
+func safeArrayGetElementString(safearray *SafeArray, index int32) (str string, err error) {
+	var element *int16
+	err = convertHresultToError(
+		procSafeArrayGetElement.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&index)),
+			uintptr(unsafe.Pointer(&element))))
+	str = BstrToString(*(**uint16)(unsafe.Pointer(&element)))
+	SysFreeString(element)
+	return
+}
+
+// safeArrayGetIID is the InterfaceID of the elements in the SafeArray.
+//
+// AKA: SafeArrayGetIID in Windows API.
+func safeArrayGetIID(safearray *SafeArray) (guid *GUID, err error) {
+	err = convertHresultToError(
+		procSafeArrayGetIID.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&guid))))
+	return
+}
+
+// safeArrayGetLBound returns lower bounds of SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetLBound in Windows API.
+func safeArrayGetLBound(safearray *SafeArray, dimension uint32) (lowerBound int32, err error) {
+	err = convertHresultToError(
+		procSafeArrayGetLBound.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(dimension),
+			uintptr(unsafe.Pointer(&lowerBound))))
+	return
+}
+
+// safeArrayGetUBound returns upper bounds of SafeArray.
+//
+// SafeArrays may have multiple dimensions. Meaning, it could be
+// multidimensional array.
+//
+// AKA: SafeArrayGetUBound in Windows API.
+func safeArrayGetUBound(safearray *SafeArray, dimension uint32) (upperBound int32, err error) {
+	err = convertHresultToError(
+		procSafeArrayGetUBound.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(dimension),
+			uintptr(unsafe.Pointer(&upperBound))))
+	return
+}
+
+// safeArrayGetVartype returns data type of SafeArray.
+//
+// AKA: SafeArrayGetVartype in Windows API.
+func safeArrayGetVartype(safearray *SafeArray) (varType uint16, err error) {
+	err = convertHresultToError(
+		procSafeArrayGetVartype.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&varType))))
+	return
+}
+
+// safeArrayLock locks SafeArray for reading to modify SafeArray.
+//
+// This must be called during some calls to ensure that another process does not
+// read or write to the SafeArray during editing.
+//
+// AKA: SafeArrayLock in Windows API.
+func safeArrayLock(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayLock.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayUnlock unlocks SafeArray for reading.
+//
+// AKA: SafeArrayUnlock in Windows API.
+func safeArrayUnlock(safearray *SafeArray) (err error) {
+	err = convertHresultToError(procSafeArrayUnlock.Call(uintptr(unsafe.Pointer(safearray))))
+	return
+}
+
+// safeArrayPutElement stores the data element at the specified location in the
+// array.
+//
+// AKA: SafeArrayPutElement in Windows API.
+func safeArrayPutElement(safearray *SafeArray, index int64, element uintptr) (err error) {
+	err = convertHresultToError(
+		procSafeArrayPutElement.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&index)),
+			uintptr(unsafe.Pointer(element))))
+	return
+}
+
+// safeArrayGetRecordInfo accesses IRecordInfo info for custom types.
+//
+// AKA: SafeArrayGetRecordInfo in Windows API.
+//
+// XXX: Must implement IRecordInfo interface for this to return.
+func safeArrayGetRecordInfo(safearray *SafeArray) (recordInfo interface{}, err error) {
+	err = convertHresultToError(
+		procSafeArrayGetRecordInfo.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&recordInfo))))
+	return
+}
+
+// safeArraySetRecordInfo mutates IRecordInfo info for custom types.
+//
+// AKA: SafeArraySetRecordInfo in Windows API.
+//
+// XXX: Must implement IRecordInfo interface for this to return.
+func safeArraySetRecordInfo(safearray *SafeArray, recordInfo interface{}) (err error) {
+	err = convertHresultToError(
+		procSafeArraySetRecordInfo.Call(
+			uintptr(unsafe.Pointer(safearray)),
+			uintptr(unsafe.Pointer(&recordInfo))))
+	return
+}

vendor/github.com/go-ole/go-ole/safearrayconversion.go

@@ -0,0 +1,140 @@
+// Helper for converting SafeArray to array of objects.
+
+package ole
+
+import (
+	"unsafe"
+)
+
+type SafeArrayConversion struct {
+	Array *SafeArray
+}
+
+func (sac *SafeArrayConversion) ToStringArray() (strings []string) {
+	totalElements, _ := sac.TotalElements(0)
+	strings = make([]string, totalElements)
+
+	for i := int32(0); i < totalElements; i++ {
+		strings[int32(i)], _ = safeArrayGetElementString(sac.Array, i)
+	}
+
+	return
+}
+
+func (sac *SafeArrayConversion) ToByteArray() (bytes []byte) {
+	totalElements, _ := sac.TotalElements(0)
+	bytes = make([]byte, totalElements)
+
+	for i := int32(0); i < totalElements; i++ {
+		safeArrayGetElement(sac.Array, i, unsafe.Pointer(&bytes[int32(i)]))
+	}
+
+	return
+}
+
+func (sac *SafeArrayConversion) ToValueArray() (values []interface{}) {
+	totalElements, _ := sac.TotalElements(0)
+	values = make([]interface{}, totalElements)
+	vt, _ := safeArrayGetVartype(sac.Array)
+
+	for i := int32(0); i < totalElements; i++ {
+		switch VT(vt) {
+		case VT_BOOL:
+			var v bool
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_I1:
+			var v int8
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_I2:
+			var v int16
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_I4:
+			var v int32
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_I8:
+			var v int64
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_UI1:
+			var v uint8
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_UI2:
+			var v uint16
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_UI4:
+			var v uint32
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_UI8:
+			var v uint64
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_R4:
+			var v float32
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_R8:
+			var v float64
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_BSTR:
+			var v string
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v
+		case VT_VARIANT:
+			var v VARIANT
+			safeArrayGetElement(sac.Array, i, unsafe.Pointer(&v))
+			values[i] = v.Value()
+		default:
+			// TODO
+		}
+	}
+
+	return
+}
+
+func (sac *SafeArrayConversion) GetType() (varType uint16, err error) {
+	return safeArrayGetVartype(sac.Array)
+}
+
+func (sac *SafeArrayConversion) GetDimensions() (dimensions *uint32, err error) {
+	return safeArrayGetDim(sac.Array)
+}
+
+func (sac *SafeArrayConversion) GetSize() (length *uint32, err error) {
+	return safeArrayGetElementSize(sac.Array)
+}
+
+func (sac *SafeArrayConversion) TotalElements(index uint32) (totalElements int32, err error) {
+	if index < 1 {
+		index = 1
+	}
+
+	// Get array bounds
+	var LowerBounds int32
+	var UpperBounds int32
+
+	LowerBounds, err = safeArrayGetLBound(sac.Array, index)
+	if err != nil {
+		return
+	}
+
+	UpperBounds, err = safeArrayGetUBound(sac.Array, index)
+	if err != nil {
+		return
+	}
+
+	totalElements = UpperBounds - LowerBounds + 1
+	return
+}
+
+// Release Safe Array memory
+func (sac *SafeArrayConversion) Release() {
+	safeArrayDestroy(sac.Array)
+}

vendor/github.com/go-ole/go-ole/safearrayslices.go

@@ -0,0 +1,33 @@
+// +build windows
+
+package ole
+
+import (
+	"unsafe"
+)
+
+func safeArrayFromByteSlice(slice []byte) *SafeArray {
+	array, _ := safeArrayCreateVector(VT_UI1, 0, uint32(len(slice)))
+
+	if array == nil {
+		panic("Could not convert []byte to SAFEARRAY")
+	}
+
+	for i, v := range slice {
+		safeArrayPutElement(array, int64(i), uintptr(unsafe.Pointer(&v)))
+	}
+	return array
+}
+
+func safeArrayFromStringSlice(slice []string) *SafeArray {
+	array, _ := safeArrayCreateVector(VT_BSTR, 0, uint32(len(slice)))
+
+	if array == nil {
+		panic("Could not convert []string to SAFEARRAY")
+	}
+	// SysAllocStringLen(s)
+	for i, v := range slice {
+		safeArrayPutElement(array, int64(i), uintptr(unsafe.Pointer(SysAllocStringLen(v))))
+	}
+	return array
+}

vendor/github.com/go-ole/go-ole/utility.go

@@ -0,0 +1,101 @@
+package ole
+
+import (
+	"unicode/utf16"
+	"unsafe"
+)
+
+// ClassIDFrom retrieves class ID whether given is program ID or application string.
+//
+// Helper that provides check against both Class ID from Program ID and Class ID from string. It is
+// faster, if you know which you are using, to use the individual functions, but this will check
+// against available functions for you.
+func ClassIDFrom(programID string) (classID *GUID, err error) {
+	classID, err = CLSIDFromProgID(programID)
+	if err != nil {
+		classID, err = CLSIDFromString(programID)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// BytePtrToString converts byte pointer to a Go string.
+func BytePtrToString(p *byte) string {
+	a := (*[10000]uint8)(unsafe.Pointer(p))
+	i := 0
+	for a[i] != 0 {
+		i++
+	}
+	return string(a[:i])
+}
+
+// UTF16PtrToString is alias for LpOleStrToString.
+//
+// Kept for compatibility reasons.
+func UTF16PtrToString(p *uint16) string {
+	return LpOleStrToString(p)
+}
+
+// LpOleStrToString converts COM Unicode to Go string.
+func LpOleStrToString(p *uint16) string {
+	if p == nil {
+		return ""
+	}
+
+	length := lpOleStrLen(p)
+	a := make([]uint16, length)
+
+	ptr := unsafe.Pointer(p)
+
+	for i := 0; i < int(length); i++ {
+		a[i] = *(*uint16)(ptr)
+		ptr = unsafe.Pointer(uintptr(ptr) + 2)
+	}
+
+	return string(utf16.Decode(a))
+}
+
+// BstrToString converts COM binary string to Go string.
+func BstrToString(p *uint16) string {
+	if p == nil {
+		return ""
+	}
+	length := SysStringLen((*int16)(unsafe.Pointer(p)))
+	a := make([]uint16, length)
+
+	ptr := unsafe.Pointer(p)
+
+	for i := 0; i < int(length); i++ {
+		a[i] = *(*uint16)(ptr)
+		ptr = unsafe.Pointer(uintptr(ptr) + 2)
+	}
+	return string(utf16.Decode(a))
+}
+
+// lpOleStrLen returns the length of Unicode string.
+func lpOleStrLen(p *uint16) (length int64) {
+	if p == nil {
+		return 0
+	}
+
+	ptr := unsafe.Pointer(p)
+
+	for i := 0; ; i++ {
+		if 0 == *(*uint16)(ptr) {
+			length = int64(i)
+			break
+		}
+		ptr = unsafe.Pointer(uintptr(ptr) + 2)
+	}
+	return
+}
+
+// convertHresultToError converts syscall to error, if call is unsuccessful.
+func convertHresultToError(hr uintptr, r2 uintptr, ignore error) (err error) {
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}

vendor/github.com/go-ole/go-ole/variables.go

@@ -0,0 +1,16 @@
+// +build windows
+
+package ole
+
+import (
+	"syscall"
+)
+
+var (
+	modcombase     = syscall.NewLazyDLL("combase.dll")
+	modkernel32, _ = syscall.LoadDLL("kernel32.dll")
+	modole32, _    = syscall.LoadDLL("ole32.dll")
+	modoleaut32, _ = syscall.LoadDLL("oleaut32.dll")
+	modmsvcrt, _   = syscall.LoadDLL("msvcrt.dll")
+	moduser32, _   = syscall.LoadDLL("user32.dll")
+)

vendor/github.com/go-ole/go-ole/variant.go

@@ -0,0 +1,105 @@
+package ole
+
+import "unsafe"
+
+// NewVariant returns new variant based on type and value.
+func NewVariant(vt VT, val int64) VARIANT {
+	return VARIANT{VT: vt, Val: val}
+}
+
+// ToIUnknown converts Variant to Unknown object.
+func (v *VARIANT) ToIUnknown() *IUnknown {
+	if v.VT != VT_UNKNOWN {
+		return nil
+	}
+	return (*IUnknown)(unsafe.Pointer(uintptr(v.Val)))
+}
+
+// ToIDispatch converts variant to dispatch object.
+func (v *VARIANT) ToIDispatch() *IDispatch {
+	if v.VT != VT_DISPATCH {
+		return nil
+	}
+	return (*IDispatch)(unsafe.Pointer(uintptr(v.Val)))
+}
+
+// ToArray converts variant to SafeArray helper.
+func (v *VARIANT) ToArray() *SafeArrayConversion {
+	if v.VT != VT_SAFEARRAY {
+		if v.VT&VT_ARRAY == 0 {
+			return nil
+		}
+	}
+	var safeArray *SafeArray = (*SafeArray)(unsafe.Pointer(uintptr(v.Val)))
+	return &SafeArrayConversion{safeArray}
+}
+
+// ToString converts variant to Go string.
+func (v *VARIANT) ToString() string {
+	if v.VT != VT_BSTR {
+		return ""
+	}
+	return BstrToString(*(**uint16)(unsafe.Pointer(&v.Val)))
+}
+
+// Clear the memory of variant object.
+func (v *VARIANT) Clear() error {
+	return VariantClear(v)
+}
+
+// Value returns variant value based on its type.
+//
+// Currently supported types: 2- and 4-byte integers, strings, bools.
+// Note that 64-bit integers, datetimes, and other types are stored as strings
+// and will be returned as strings.
+//
+// Needs to be further converted, because this returns an interface{}.
+func (v *VARIANT) Value() interface{} {
+	switch v.VT {
+	case VT_I1:
+		return int8(v.Val)
+	case VT_UI1:
+		return uint8(v.Val)
+	case VT_I2:
+		return int16(v.Val)
+	case VT_UI2:
+		return uint16(v.Val)
+	case VT_I4:
+		return int32(v.Val)
+	case VT_UI4:
+		return uint32(v.Val)
+	case VT_I8:
+		return int64(v.Val)
+	case VT_UI8:
+		return uint64(v.Val)
+	case VT_INT:
+		return int(v.Val)
+	case VT_UINT:
+		return uint(v.Val)
+	case VT_INT_PTR:
+		return uintptr(v.Val) // TODO
+	case VT_UINT_PTR:
+		return uintptr(v.Val)
+	case VT_R4:
+		return *(*float32)(unsafe.Pointer(&v.Val))
+	case VT_R8:
+		return *(*float64)(unsafe.Pointer(&v.Val))
+	case VT_BSTR:
+		return v.ToString()
+	case VT_DATE:
+		// VT_DATE type will either return float64 or time.Time.
+		d := uint64(v.Val)
+		date, err := GetVariantDate(d)
+		if err != nil {
+			return float64(v.Val)
+		}
+		return date
+	case VT_UNKNOWN:
+		return v.ToIUnknown()
+	case VT_DISPATCH:
+		return v.ToIDispatch()
+	case VT_BOOL:
+		return v.Val != 0
+	}
+	return nil
+}

vendor/github.com/go-ole/go-ole/variant_386.go

@@ -0,0 +1,11 @@
+// +build 386
+
+package ole
+
+type VARIANT struct {
+	VT         VT     //  2
+	wReserved1 uint16 //  4
+	wReserved2 uint16 //  6
+	wReserved3 uint16 //  8
+	Val        int64  // 16
+}

vendor/github.com/go-ole/go-ole/variant_amd64.go

@@ -0,0 +1,12 @@
+// +build amd64
+
+package ole
+
+type VARIANT struct {
+	VT         VT      //  2
+	wReserved1 uint16  //  4
+	wReserved2 uint16  //  6
+	wReserved3 uint16  //  8
+	Val        int64   // 16
+	_          [8]byte // 24
+}

vendor/github.com/go-ole/go-ole/variant_date_386.go

@@ -0,0 +1,22 @@
+// +build windows,386
+
+package ole
+
+import (
+	"errors"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// GetVariantDate converts COM Variant Time value to Go time.Time.
+func GetVariantDate(value uint64) (time.Time, error) {
+	var st syscall.Systemtime
+	v1 := uint32(value)
+	v2 := uint32(value >> 32)
+	r, _, _ := procVariantTimeToSystemTime.Call(uintptr(v1), uintptr(v2), uintptr(unsafe.Pointer(&st)))
+	if r != 0 {
+		return time.Date(int(st.Year), time.Month(st.Month), int(st.Day), int(st.Hour), int(st.Minute), int(st.Second), int(st.Milliseconds/1000), time.UTC), nil
+	}
+	return time.Now(), errors.New("Could not convert to time, passing current time.")
+}

vendor/github.com/go-ole/go-ole/variant_date_amd64.go

@@ -0,0 +1,20 @@
+// +build windows,amd64
+
+package ole
+
+import (
+	"errors"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+// GetVariantDate converts COM Variant Time value to Go time.Time.
+func GetVariantDate(value uint64) (time.Time, error) {
+	var st syscall.Systemtime
+	r, _, _ := procVariantTimeToSystemTime.Call(uintptr(value), uintptr(unsafe.Pointer(&st)))
+	if r != 0 {
+		return time.Date(int(st.Year), time.Month(st.Month), int(st.Day), int(st.Hour), int(st.Minute), int(st.Second), int(st.Milliseconds/1000), time.UTC), nil
+	}
+	return time.Now(), errors.New("Could not convert to time, passing current time.")
+}

vendor/github.com/go-ole/go-ole/variant_ppc64le.go

@@ -0,0 +1,12 @@
+// +build ppc64le
+
+package ole
+
+type VARIANT struct {
+	VT         VT      //  2
+	wReserved1 uint16  //  4
+	wReserved2 uint16  //  6
+	wReserved3 uint16  //  8
+	Val        int64   // 16
+	_          [8]byte // 24
+}

vendor/github.com/go-ole/go-ole/variant_s390x.go

@@ -0,0 +1,12 @@
+// +build s390x
+
+package ole
+
+type VARIANT struct {
+	VT         VT      //  2
+	wReserved1 uint16  //  4
+	wReserved2 uint16  //  6
+	wReserved3 uint16  //  8
+	Val        int64   // 16
+	_          [8]byte // 24
+}

vendor/github.com/go-ole/go-ole/vt_string.go

@@ -0,0 +1,58 @@
+// generated by stringer -output vt_string.go -type VT; DO NOT EDIT
+
+package ole
+
+import "fmt"
+
+const (
+	_VT_name_0 = "VT_EMPTYVT_NULLVT_I2VT_I4VT_R4VT_R8VT_CYVT_DATEVT_BSTRVT_DISPATCHVT_ERRORVT_BOOLVT_VARIANTVT_UNKNOWNVT_DECIMAL"
+	_VT_name_1 = "VT_I1VT_UI1VT_UI2VT_UI4VT_I8VT_UI8VT_INTVT_UINTVT_VOIDVT_HRESULTVT_PTRVT_SAFEARRAYVT_CARRAYVT_USERDEFINEDVT_LPSTRVT_LPWSTR"
+	_VT_name_2 = "VT_RECORDVT_INT_PTRVT_UINT_PTR"
+	_VT_name_3 = "VT_FILETIMEVT_BLOBVT_STREAMVT_STORAGEVT_STREAMED_OBJECTVT_STORED_OBJECTVT_BLOB_OBJECTVT_CFVT_CLSID"
+	_VT_name_4 = "VT_BSTR_BLOBVT_VECTOR"
+	_VT_name_5 = "VT_ARRAY"
+	_VT_name_6 = "VT_BYREF"
+	_VT_name_7 = "VT_RESERVED"
+	_VT_name_8 = "VT_ILLEGAL"
+)
+
+var (
+	_VT_index_0 = [...]uint8{0, 8, 15, 20, 25, 30, 35, 40, 47, 54, 65, 73, 80, 90, 100, 110}
+	_VT_index_1 = [...]uint8{0, 5, 11, 17, 23, 28, 34, 40, 47, 54, 64, 70, 82, 91, 105, 113, 122}
+	_VT_index_2 = [...]uint8{0, 9, 19, 30}
+	_VT_index_3 = [...]uint8{0, 11, 18, 27, 37, 55, 71, 85, 90, 98}
+	_VT_index_4 = [...]uint8{0, 12, 21}
+	_VT_index_5 = [...]uint8{0, 8}
+	_VT_index_6 = [...]uint8{0, 8}
+	_VT_index_7 = [...]uint8{0, 11}
+	_VT_index_8 = [...]uint8{0, 10}
+)
+
+func (i VT) String() string {
+	switch {
+	case 0 <= i && i <= 14:
+		return _VT_name_0[_VT_index_0[i]:_VT_index_0[i+1]]
+	case 16 <= i && i <= 31:
+		i -= 16
+		return _VT_name_1[_VT_index_1[i]:_VT_index_1[i+1]]
+	case 36 <= i && i <= 38:
+		i -= 36
+		return _VT_name_2[_VT_index_2[i]:_VT_index_2[i+1]]
+	case 64 <= i && i <= 72:
+		i -= 64
+		return _VT_name_3[_VT_index_3[i]:_VT_index_3[i+1]]
+	case 4095 <= i && i <= 4096:
+		i -= 4095
+		return _VT_name_4[_VT_index_4[i]:_VT_index_4[i+1]]
+	case i == 8192:
+		return _VT_name_5
+	case i == 16384:
+		return _VT_name_6
+	case i == 32768:
+		return _VT_name_7
+	case i == 65535:
+		return _VT_name_8
+	default:
+		return fmt.Sprintf("VT(%d)", i)
+	}
+}

vendor/github.com/go-ole/go-ole/winrt.go

@@ -0,0 +1,99 @@
+// +build windows
+
+package ole
+
+import (
+	"reflect"
+	"syscall"
+	"unicode/utf8"
+	"unsafe"
+)
+
+var (
+	procRoInitialize              = modcombase.NewProc("RoInitialize")
+	procRoActivateInstance        = modcombase.NewProc("RoActivateInstance")
+	procRoGetActivationFactory    = modcombase.NewProc("RoGetActivationFactory")
+	procWindowsCreateString       = modcombase.NewProc("WindowsCreateString")
+	procWindowsDeleteString       = modcombase.NewProc("WindowsDeleteString")
+	procWindowsGetStringRawBuffer = modcombase.NewProc("WindowsGetStringRawBuffer")
+)
+
+func RoInitialize(thread_type uint32) (err error) {
+	hr, _, _ := procRoInitialize.Call(uintptr(thread_type))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func RoActivateInstance(clsid string) (ins *IInspectable, err error) {
+	hClsid, err := NewHString(clsid)
+	if err != nil {
+		return nil, err
+	}
+	defer DeleteHString(hClsid)
+
+	hr, _, _ := procRoActivateInstance.Call(
+		uintptr(unsafe.Pointer(hClsid)),
+		uintptr(unsafe.Pointer(&ins)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+func RoGetActivationFactory(clsid string, iid *GUID) (ins *IInspectable, err error) {
+	hClsid, err := NewHString(clsid)
+	if err != nil {
+		return nil, err
+	}
+	defer DeleteHString(hClsid)
+
+	hr, _, _ := procRoGetActivationFactory.Call(
+		uintptr(unsafe.Pointer(hClsid)),
+		uintptr(unsafe.Pointer(iid)),
+		uintptr(unsafe.Pointer(&ins)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// HString is handle string for pointers.
+type HString uintptr
+
+// NewHString returns a new HString for Go string.
+func NewHString(s string) (hstring HString, err error) {
+	u16 := syscall.StringToUTF16Ptr(s)
+	len := uint32(utf8.RuneCountInString(s))
+	hr, _, _ := procWindowsCreateString.Call(
+		uintptr(unsafe.Pointer(u16)),
+		uintptr(len),
+		uintptr(unsafe.Pointer(&hstring)))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// DeleteHString deletes HString.
+func DeleteHString(hstring HString) (err error) {
+	hr, _, _ := procWindowsDeleteString.Call(uintptr(hstring))
+	if hr != 0 {
+		err = NewError(hr)
+	}
+	return
+}
+
+// String returns Go string value of HString.
+func (h HString) String() string {
+	var u16buf uintptr
+	var u16len uint32
+	u16buf, _, _ = procWindowsGetStringRawBuffer.Call(
+		uintptr(h),
+		uintptr(unsafe.Pointer(&u16len)))
+
+	u16hdr := reflect.SliceHeader{Data: u16buf, Len: int(u16len), Cap: int(u16len)}
+	u16 := *(*[]uint16)(unsafe.Pointer(&u16hdr))
+	return syscall.UTF16ToString(u16)
+}

vendor/github.com/go-ole/go-ole/winrt_doc.go

@@ -0,0 +1,36 @@
+// +build !windows
+
+package ole
+
+// RoInitialize
+func RoInitialize(thread_type uint32) (err error) {
+	return NewError(E_NOTIMPL)
+}
+
+// RoActivateInstance
+func RoActivateInstance(clsid string) (ins *IInspectable, err error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// RoGetActivationFactory
+func RoGetActivationFactory(clsid string, iid *GUID) (ins *IInspectable, err error) {
+	return nil, NewError(E_NOTIMPL)
+}
+
+// HString is handle string for pointers.
+type HString uintptr
+
+// NewHString returns a new HString for Go string.
+func NewHString(s string) (hstring HString, err error) {
+	return HString(uintptr(0)), NewError(E_NOTIMPL)
+}
+
+// DeleteHString deletes HString.
+func DeleteHString(hstring HString) (err error) {
+	return NewError(E_NOTIMPL)
+}
+
+// String returns Go string value of HString.
+func (h HString) String() string {
+	return ""
+}

vendor/github.com/google/btree/btree.go

@@ -22,7 +22,7 @@
 // See some discussion on the matter here:
 //   http://google-opensource.blogspot.com/2013/01/c-containers-that-save-memory-and-time.html
 // Note, though, that this project is in no way related to the C++ B-Tree
-// implmentation written about there.
+// implementation written about there.
 //
 // Within this tree, each node contains a slice of items and a (possibly nil)
 // slice of children.  For basic numeric values or raw structs, this can cause
@@ -44,7 +44,7 @@
 // widely used ordered tree implementation in the Go ecosystem currently.
 // Its functions, therefore, exactly mirror those of
 // llrb.LLRB where possible.  Unlike gollrb, though, we currently don't
-// support storing multiple equivalent values or backwards iteration.
+// support storing multiple equivalent values.
 package btree
 
 import (
@@ -52,6 +52,7 @@ import (
 	"io"
 	"sort"
 	"strings"
+	"sync"
 )
 
 // Item represents a single object in the tree.
@@ -68,11 +69,17 @@ const (
 	DefaultFreeListSize = 32
 )
 
+var (
+	nilItems    = make(items, 16)
+	nilChildren = make(children, 16)
+)
+
 // FreeList represents a free list of btree nodes. By default each
 // BTree has its own FreeList, but multiple BTrees can share the same
 // FreeList.
-// Two Btrees using the same freelist are not safe for concurrent write access.
+// Two Btrees using the same freelist are safe for concurrent write access.
 type FreeList struct {
+	mu       sync.Mutex
 	freelist []*node
 }
 
@@ -83,18 +90,29 @@ func NewFreeList(size int) *FreeList {
 }
 
 func (f *FreeList) newNode() (n *node) {
+	f.mu.Lock()
 	index := len(f.freelist) - 1
 	if index < 0 {
+		f.mu.Unlock()
 		return new(node)
 	}
-	f.freelist, n = f.freelist[:index], f.freelist[index]
+	n = f.freelist[index]
+	f.freelist[index] = nil
+	f.freelist = f.freelist[:index]
+	f.mu.Unlock()
 	return
 }
 
-func (f *FreeList) freeNode(n *node) {
+// freeNode adds the given node to the list, returning true if it was added
+// and false if it was discarded.
+func (f *FreeList) freeNode(n *node) (out bool) {
+	f.mu.Lock()
 	if len(f.freelist) < cap(f.freelist) {
 		f.freelist = append(f.freelist, n)
+		out = true
 	}
+	f.mu.Unlock()
+	return
 }
 
 // ItemIterator allows callers of Ascend* to iterate in-order over portions of
@@ -116,8 +134,8 @@ func NewWithFreeList(degree int, f *FreeList) *BTree {
 		panic("bad degree")
 	}
 	return &BTree{
-		degree:   degree,
-		freelist: f,
+		degree: degree,
+		cow:    &copyOnWriteContext{freelist: f},
 	}
 }
 
@@ -138,8 +156,8 @@ func (s *items) insertAt(index int, item Item) {
 // back.
 func (s *items) removeAt(index int) Item {
 	item := (*s)[index]
-	(*s)[index] = nil
 	copy((*s)[index:], (*s)[index+1:])
+	(*s)[len(*s)-1] = nil
 	*s = (*s)[:len(*s)-1]
 	return item
 }
@@ -153,6 +171,16 @@ func (s *items) pop() (out Item) {
 	return
 }
 
+// truncate truncates this instance at index so that it contains only the
+// first index items. index must be less than or equal to length.
+func (s *items) truncate(index int) {
+	var toClear items
+	*s, toClear = (*s)[:index], (*s)[index:]
+	for len(toClear) > 0 {
+		toClear = toClear[copy(toClear, nilItems):]
+	}
+}
+
 // find returns the index where the given item should be inserted into this
 // list.  'found' is true if the item already exists in the list at the given
 // index.
@@ -183,8 +211,8 @@ func (s *children) insertAt(index int, n *node) {
 // back.
 func (s *children) removeAt(index int) *node {
 	n := (*s)[index]
-	(*s)[index] = nil
 	copy((*s)[index:], (*s)[index+1:])
+	(*s)[len(*s)-1] = nil
 	*s = (*s)[:len(*s)-1]
 	return n
 }
@@ -198,6 +226,16 @@ func (s *children) pop() (out *node) {
 	return
 }
 
+// truncate truncates this instance at index so that it contains only the
+// first index children. index must be less than or equal to length.
+func (s *children) truncate(index int) {
+	var toClear children
+	*s, toClear = (*s)[:index], (*s)[index:]
+	for len(toClear) > 0 {
+		toClear = toClear[copy(toClear, nilChildren):]
+	}
+}
+
 // node is an internal node in a tree.
 //
 // It must at all times maintain the invariant that either
@@ -206,7 +244,34 @@ func (s *children) pop() (out *node) {
 type node struct {
 	items    items
 	children children
-	t        *BTree
+	cow      *copyOnWriteContext
+}
+
+func (n *node) mutableFor(cow *copyOnWriteContext) *node {
+	if n.cow == cow {
+		return n
+	}
+	out := cow.newNode()
+	if cap(out.items) >= len(n.items) {
+		out.items = out.items[:len(n.items)]
+	} else {
+		out.items = make(items, len(n.items), cap(n.items))
+	}
+	copy(out.items, n.items)
+	// Copy children
+	if cap(out.children) >= len(n.children) {
+		out.children = out.children[:len(n.children)]
+	} else {
+		out.children = make(children, len(n.children), cap(n.children))
+	}
+	copy(out.children, n.children)
+	return out
+}
+
+func (n *node) mutableChild(i int) *node {
+	c := n.children[i].mutableFor(n.cow)
+	n.children[i] = c
+	return c
 }
 
 // split splits the given node at the given index.  The current node shrinks,
@@ -214,12 +279,12 @@ type node struct {
 // containing all items/children after it.
 func (n *node) split(i int) (Item, *node) {
 	item := n.items[i]
-	next := n.t.newNode()
+	next := n.cow.newNode()
 	next.items = append(next.items, n.items[i+1:]...)
-	n.items = n.items[:i]
+	n.items.truncate(i)
 	if len(n.children) > 0 {
 		next.children = append(next.children, n.children[i+1:]...)
-		n.children = n.children[:i+1]
+		n.children.truncate(i + 1)
 	}
 	return item, next
 }
@@ -230,7 +295,7 @@ func (n *node) maybeSplitChild(i, maxItems int) bool {
 	if len(n.children[i].items) < maxItems {
 		return false
 	}
-	first := n.children[i]
+	first := n.mutableChild(i)
 	item, second := first.split(maxItems / 2)
 	n.items.insertAt(i, item)
 	n.children.insertAt(i+1, second)
@@ -264,7 +329,7 @@ func (n *node) insert(item Item, maxItems int) Item {
 			return out
 		}
 	}
-	return n.children[i].insert(item, maxItems)
+	return n.mutableChild(i).insert(item, maxItems)
 }
 
 // get finds the given key in the subtree and returns it.
@@ -342,10 +407,10 @@ func (n *node) remove(item Item, minItems int, typ toRemove) Item {
 		panic("invalid type")
 	}
 	// If we get to here, we have children.
-	child := n.children[i]
-	if len(child.items) <= minItems {
+	if len(n.children[i].items) <= minItems {
 		return n.growChildAndRemove(i, item, minItems, typ)
 	}
+	child := n.mutableChild(i)
 	// Either we had enough items to begin with, or we've done some
 	// merging/stealing, because we've got enough now and we're ready to return
 	// stuff.
@@ -384,10 +449,10 @@ func (n *node) remove(item Item, minItems int, typ toRemove) Item {
 // whether we're in case 1 or 2), we'll have enough items and can guarantee
 // that we hit case A.
 func (n *node) growChildAndRemove(i int, item Item, minItems int, typ toRemove) Item {
-	child := n.children[i]
 	if i > 0 && len(n.children[i-1].items) > minItems {
 		// Steal from left child
-		stealFrom := n.children[i-1]
+		child := n.mutableChild(i)
+		stealFrom := n.mutableChild(i - 1)
 		stolenItem := stealFrom.items.pop()
 		child.items.insertAt(0, n.items[i-1])
 		n.items[i-1] = stolenItem
@@ -396,7 +461,8 @@ func (n *node) growChildAndRemove(i int, item Item, minItems int, typ toRemove)
 		}
 	} else if i < len(n.items) && len(n.children[i+1].items) > minItems {
 		// steal from right child
-		stealFrom := n.children[i+1]
+		child := n.mutableChild(i)
+		stealFrom := n.mutableChild(i + 1)
 		stolenItem := stealFrom.items.removeAt(0)
 		child.items = append(child.items, n.items[i])
 		n.items[i] = stolenItem
@@ -406,47 +472,99 @@ func (n *node) growChildAndRemove(i int, item Item, minItems int, typ toRemove)
 	} else {
 		if i >= len(n.items) {
 			i--
-			child = n.children[i]
 		}
+		child := n.mutableChild(i)
 		// merge with right child
 		mergeItem := n.items.removeAt(i)
 		mergeChild := n.children.removeAt(i + 1)
 		child.items = append(child.items, mergeItem)
 		child.items = append(child.items, mergeChild.items...)
 		child.children = append(child.children, mergeChild.children...)
-		n.t.freeNode(mergeChild)
+		n.cow.freeNode(mergeChild)
 	}
 	return n.remove(item, minItems, typ)
 }
 
+type direction int
+
+const (
+	descend = direction(-1)
+	ascend  = direction(+1)
+)
+
 // iterate provides a simple method for iterating over elements in the tree.
-// It could probably use some work to be extra-efficient (it calls from() a
-// little more than it should), but it works pretty well for now.
 //
-// It requires that 'from' and 'to' both return true for values we should hit
-// with the iterator.  It should also be the case that 'from' returns true for
-// values less than or equal to values 'to' returns true for, and 'to'
-// returns true for values greater than or equal to those that 'from'
-// does.
-func (n *node) iterate(from, to func(Item) bool, iter ItemIterator) bool {
-	for i, item := range n.items {
-		if !from(item) {
-			continue
+// When ascending, the 'start' should be less than 'stop' and when descending,
+// the 'start' should be greater than 'stop'. Setting 'includeStart' to true
+// will force the iterator to include the first item when it equals 'start',
+// thus creating a "greaterOrEqual" or "lessThanEqual" rather than just a
+// "greaterThan" or "lessThan" queries.
+func (n *node) iterate(dir direction, start, stop Item, includeStart bool, hit bool, iter ItemIterator) (bool, bool) {
+	var ok, found bool
+	var index int
+	switch dir {
+	case ascend:
+		if start != nil {
+			index, _ = n.items.find(start)
 		}
-		if len(n.children) > 0 && !n.children[i].iterate(from, to, iter) {
-			return false
+		for i := index; i < len(n.items); i++ {
+			if len(n.children) > 0 {
+				if hit, ok = n.children[i].iterate(dir, start, stop, includeStart, hit, iter); !ok {
+					return hit, false
+				}
+			}
+			if !includeStart && !hit && start != nil && !start.Less(n.items[i]) {
+				hit = true
+				continue
+			}
+			hit = true
+			if stop != nil && !n.items[i].Less(stop) {
+				return hit, false
+			}
+			if !iter(n.items[i]) {
+				return hit, false
+			}
 		}
-		if !to(item) {
-			return false
+		if len(n.children) > 0 {
+			if hit, ok = n.children[len(n.children)-1].iterate(dir, start, stop, includeStart, hit, iter); !ok {
+				return hit, false
+			}
 		}
-		if !iter(item) {
-			return false
+	case descend:
+		if start != nil {
+			index, found = n.items.find(start)
+			if !found {
+				index = index - 1
+			}
+		} else {
+			index = len(n.items) - 1
+		}
+		for i := index; i >= 0; i-- {
+			if start != nil && !n.items[i].Less(start) {
+				if !includeStart || hit || start.Less(n.items[i]) {
+					continue
+				}
+			}
+			if len(n.children) > 0 {
+				if hit, ok = n.children[i+1].iterate(dir, start, stop, includeStart, hit, iter); !ok {
+					return hit, false
+				}
+			}
+			if stop != nil && !stop.Less(n.items[i]) {
+				return hit, false //	continue
+			}
+			hit = true
+			if !iter(n.items[i]) {
+				return hit, false
+			}
+		}
+		if len(n.children) > 0 {
+			if hit, ok = n.children[0].iterate(dir, start, stop, includeStart, hit, iter); !ok {
+				return hit, false
+			}
 		}
 	}
-	if len(n.children) > 0 {
-		return n.children[len(n.children)-1].iterate(from, to, iter)
-	}
-	return true
+	return hit, true
 }
 
 // Used for testing/debugging purposes.
@@ -465,12 +583,54 @@ func (n *node) print(w io.Writer, level int) {
 // Write operations are not safe for concurrent mutation by multiple
 // goroutines, but Read operations are.
 type BTree struct {
-	degree   int
-	length   int
-	root     *node
+	degree int
+	length int
+	root   *node
+	cow    *copyOnWriteContext
+}
+
+// copyOnWriteContext pointers determine node ownership... a tree with a write
+// context equivalent to a node's write context is allowed to modify that node.
+// A tree whose write context does not match a node's is not allowed to modify
+// it, and must create a new, writable copy (IE: it's a Clone).
+//
+// When doing any write operation, we maintain the invariant that the current
+// node's context is equal to the context of the tree that requested the write.
+// We do this by, before we descend into any node, creating a copy with the
+// correct context if the contexts don't match.
+//
+// Since the node we're currently visiting on any write has the requesting
+// tree's context, that node is modifiable in place.  Children of that node may
+// not share context, but before we descend into them, we'll make a mutable
+// copy.
+type copyOnWriteContext struct {
 	freelist *FreeList
 }
 
+// Clone clones the btree, lazily.  Clone should not be called concurrently,
+// but the original tree (t) and the new tree (t2) can be used concurrently
+// once the Clone call completes.
+//
+// The internal tree structure of b is marked read-only and shared between t and
+// t2.  Writes to both t and t2 use copy-on-write logic, creating new nodes
+// whenever one of b's original nodes would have been modified.  Read operations
+// should have no performance degredation.  Write operations for both t and t2
+// will initially experience minor slow-downs caused by additional allocs and
+// copies due to the aforementioned copy-on-write logic, but should converge to
+// the original performance characteristics of the original tree.
+func (t *BTree) Clone() (t2 *BTree) {
+	// Create two entirely new copy-on-write contexts.
+	// This operation effectively creates three trees:
+	//   the original, shared nodes (old b.cow)
+	//   the new b.cow nodes
+	//   the new out.cow nodes
+	cow1, cow2 := *t.cow, *t.cow
+	out := *t
+	t.cow = &cow1
+	out.cow = &cow2
+	return &out
+}
+
 // maxItems returns the max number of items to allow per node.
 func (t *BTree) maxItems() int {
 	return t.degree*2 - 1
@@ -482,23 +642,37 @@ func (t *BTree) minItems() int {
 	return t.degree - 1
 }
 
-func (t *BTree) newNode() (n *node) {
-	n = t.freelist.newNode()
-	n.t = t
+func (c *copyOnWriteContext) newNode() (n *node) {
+	n = c.freelist.newNode()
+	n.cow = c
 	return
 }
 
-func (t *BTree) freeNode(n *node) {
-	for i := range n.items {
-		n.items[i] = nil // clear to allow GC
+type freeType int
+
+const (
+	ftFreelistFull freeType = iota // node was freed (available for GC, not stored in freelist)
+	ftStored                       // node was stored in the freelist for later use
+	ftNotOwned                     // node was ignored by COW, since it's owned by another one
+)
+
+// freeNode frees a node within a given COW context, if it's owned by that
+// context.  It returns what happened to the node (see freeType const
+// documentation).
+func (c *copyOnWriteContext) freeNode(n *node) freeType {
+	if n.cow == c {
+		// clear to allow GC
+		n.items.truncate(0)
+		n.children.truncate(0)
+		n.cow = nil
+		if c.freelist.freeNode(n) {
+			return ftStored
+		} else {
+			return ftFreelistFull
+		}
+	} else {
+		return ftNotOwned
 	}
-	n.items = n.items[:0]
-	for i := range n.children {
-		n.children[i] = nil // clear to allow GC
-	}
-	n.children = n.children[:0]
-	n.t = nil // clear to allow GC
-	t.freelist.freeNode(n)
 }
 
 // ReplaceOrInsert adds the given item to the tree.  If an item in the tree
@@ -511,16 +685,19 @@ func (t *BTree) ReplaceOrInsert(item Item) Item {
 		panic("nil item being added to BTree")
 	}
 	if t.root == nil {
-		t.root = t.newNode()
+		t.root = t.cow.newNode()
 		t.root.items = append(t.root.items, item)
 		t.length++
 		return nil
-	} else if len(t.root.items) >= t.maxItems() {
-		item2, second := t.root.split(t.maxItems() / 2)
-		oldroot := t.root
-		t.root = t.newNode()
-		t.root.items = append(t.root.items, item2)
-		t.root.children = append(t.root.children, oldroot, second)
+	} else {
+		t.root = t.root.mutableFor(t.cow)
+		if len(t.root.items) >= t.maxItems() {
+			item2, second := t.root.split(t.maxItems() / 2)
+			oldroot := t.root
+			t.root = t.cow.newNode()
+			t.root.items = append(t.root.items, item2)
+			t.root.children = append(t.root.children, oldroot, second)
+		}
 	}
 	out := t.root.insert(item, t.maxItems())
 	if out == nil {
@@ -551,11 +728,12 @@ func (t *BTree) deleteItem(item Item, typ toRemove) Item {
 	if t.root == nil || len(t.root.items) == 0 {
 		return nil
 	}
+	t.root = t.root.mutableFor(t.cow)
 	out := t.root.remove(item, t.minItems(), typ)
 	if len(t.root.items) == 0 && len(t.root.children) > 0 {
 		oldroot := t.root
 		t.root = t.root.children[0]
-		t.freeNode(oldroot)
+		t.cow.freeNode(oldroot)
 	}
 	if out != nil {
 		t.length--
@@ -569,10 +747,7 @@ func (t *BTree) AscendRange(greaterOrEqual, lessThan Item, iterator ItemIterator
 	if t.root == nil {
 		return
 	}
-	t.root.iterate(
-		func(a Item) bool { return !a.Less(greaterOrEqual) },
-		func(a Item) bool { return a.Less(lessThan) },
-		iterator)
+	t.root.iterate(ascend, greaterOrEqual, lessThan, true, false, iterator)
 }
 
 // AscendLessThan calls the iterator for every value in the tree within the range
@@ -581,10 +756,7 @@ func (t *BTree) AscendLessThan(pivot Item, iterator ItemIterator) {
 	if t.root == nil {
 		return
 	}
-	t.root.iterate(
-		func(a Item) bool { return true },
-		func(a Item) bool { return a.Less(pivot) },
-		iterator)
+	t.root.iterate(ascend, nil, pivot, false, false, iterator)
 }
 
 // AscendGreaterOrEqual calls the iterator for every value in the tree within
@@ -593,10 +765,7 @@ func (t *BTree) AscendGreaterOrEqual(pivot Item, iterator ItemIterator) {
 	if t.root == nil {
 		return
 	}
-	t.root.iterate(
-		func(a Item) bool { return !a.Less(pivot) },
-		func(a Item) bool { return true },
-		iterator)
+	t.root.iterate(ascend, pivot, nil, true, false, iterator)
 }
 
 // Ascend calls the iterator for every value in the tree within the range
@@ -605,10 +774,43 @@ func (t *BTree) Ascend(iterator ItemIterator) {
 	if t.root == nil {
 		return
 	}
-	t.root.iterate(
-		func(a Item) bool { return true },
-		func(a Item) bool { return true },
-		iterator)
+	t.root.iterate(ascend, nil, nil, false, false, iterator)
+}
+
+// DescendRange calls the iterator for every value in the tree within the range
+// [lessOrEqual, greaterThan), until iterator returns false.
+func (t *BTree) DescendRange(lessOrEqual, greaterThan Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(descend, lessOrEqual, greaterThan, true, false, iterator)
+}
+
+// DescendLessOrEqual calls the iterator for every value in the tree within the range
+// [pivot, first], until iterator returns false.
+func (t *BTree) DescendLessOrEqual(pivot Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(descend, pivot, nil, true, false, iterator)
+}
+
+// DescendGreaterThan calls the iterator for every value in the tree within
+// the range (pivot, last], until iterator returns false.
+func (t *BTree) DescendGreaterThan(pivot Item, iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(descend, nil, pivot, false, false, iterator)
+}
+
+// Descend calls the iterator for every value in the tree within the range
+// [last, first], until iterator returns false.
+func (t *BTree) Descend(iterator ItemIterator) {
+	if t.root == nil {
+		return
+	}
+	t.root.iterate(descend, nil, nil, false, false, iterator)
 }
 
 // Get looks for the key item in the tree, returning it.  It returns nil if
@@ -640,6 +842,45 @@ func (t *BTree) Len() int {
 	return t.length
 }
 
+// Clear removes all items from the btree.  If addNodesToFreelist is true,
+// t's nodes are added to its freelist as part of this call, until the freelist
+// is full.  Otherwise, the root node is simply dereferenced and the subtree
+// left to Go's normal GC processes.
+//
+// This can be much faster
+// than calling Delete on all elements, because that requires finding/removing
+// each element in the tree and updating the tree accordingly.  It also is
+// somewhat faster than creating a new tree to replace the old one, because
+// nodes from the old tree are reclaimed into the freelist for use by the new
+// one, instead of being lost to the garbage collector.
+//
+// This call takes:
+//   O(1): when addNodesToFreelist is false, this is a single operation.
+//   O(1): when the freelist is already full, it breaks out immediately
+//   O(freelist size):  when the freelist is empty and the nodes are all owned
+//       by this tree, nodes are added to the freelist until full.
+//   O(tree size):  when all nodes are owned by another tree, all nodes are
+//       iterated over looking for nodes to add to the freelist, and due to
+//       ownership, none are.
+func (t *BTree) Clear(addNodesToFreelist bool) {
+	if t.root != nil && addNodesToFreelist {
+		t.root.reset(t.cow)
+	}
+	t.root, t.length = nil, 0
+}
+
+// reset returns a subtree to the freelist.  It breaks out immediately if the
+// freelist is full, since the only benefit of iterating is to fill that
+// freelist up.  Returns true if parent reset call should continue.
+func (n *node) reset(c *copyOnWriteContext) bool {
+	for _, child := range n.children {
+		if !child.reset(c) {
+			return false
+		}
+	}
+	return c.freeNode(n) != ftFreelistFull
+}
+
 // Int implements the Item interface for integers.
 type Int int
 

vendor/github.com/hashicorp/golang-lru/LICENSE

@@ -0,0 +1,362 @@
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. "Contributor"
+
+     means each individual or legal entity that creates, contributes to the
+     creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+
+     means the combination of the Contributions of others (if any) used by a
+     Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+
+     means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+
+     means Source Code Form to which the initial Contributor has attached the
+     notice in Exhibit A, the Executable Form of such Source Code Form, and
+     Modifications of such Source Code Form, in each case including portions
+     thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+     means
+
+     a. that the initial Contributor has attached the notice described in
+        Exhibit B to the Covered Software; or
+
+     b. that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the terms of
+        a Secondary License.
+
+1.6. "Executable Form"
+
+     means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+
+     means a work that combines Covered Software with other material, in a
+     separate file or files, that is not Covered Software.
+
+1.8. "License"
+
+     means this document.
+
+1.9. "Licensable"
+
+     means having the right to grant, to the maximum extent possible, whether
+     at the time of the initial grant or subsequently, any and all of the
+     rights conveyed by this License.
+
+1.10. "Modifications"
+
+     means any of the following:
+
+     a. any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered Software; or
+
+     b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. "Patent Claims" of a Contributor
+
+      means any patent claim(s), including without limitation, method,
+      process, and apparatus claims, in any patent Licensable by such
+      Contributor that would be infringed, but for the grant of the License,
+      by the making, using, selling, offering for sale, having made, import,
+      or transfer of either its Contributions or its Contributor Version.
+
+1.12. "Secondary License"
+
+      means either the GNU General Public License, Version 2.0, the GNU Lesser
+      General Public License, Version 2.1, the GNU Affero General Public
+      License, Version 3.0, or any later versions of those licenses.
+
+1.13. "Source Code Form"
+
+      means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+
+      means an individual or a legal entity exercising rights under this
+      License. For legal entities, "You" includes any entity that controls, is
+      controlled by, or is under common control with You. For purposes of this
+      definition, "control" means (a) the power, direct or indirect, to cause
+      the direction or management of such entity, whether by contract or
+      otherwise, or (b) ownership of more than fifty percent (50%) of the
+      outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+     Each Contributor hereby grants You a world-wide, royalty-free,
+     non-exclusive license:
+
+     a. under intellectual property rights (other than patent or trademark)
+        Licensable by such Contributor to use, reproduce, make available,
+        modify, display, perform, distribute, and otherwise exploit its
+        Contributions, either on an unmodified basis, with Modifications, or
+        as part of a Larger Work; and
+
+     b. under Patent Claims of such Contributor to make, use, sell, offer for
+        sale, have made, import, and otherwise transfer either its
+        Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+     The licenses granted in Section 2.1 with respect to any Contribution
+     become effective for each Contribution on the date the Contributor first
+     distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+     The licenses granted in this Section 2 are the only rights granted under
+     this License. No additional rights or licenses will be implied from the
+     distribution or licensing of Covered Software under this License.
+     Notwithstanding Section 2.1(b) above, no patent license is granted by a
+     Contributor:
+
+     a. for any code that a Contributor has removed from Covered Software; or
+
+     b. for infringements caused by: (i) Your and any other third party's
+        modifications of Covered Software, or (ii) the combination of its
+        Contributions with other software (except as part of its Contributor
+        Version); or
+
+     c. under Patent Claims infringed by Covered Software in the absence of
+        its Contributions.
+
+     This License does not grant any rights in the trademarks, service marks,
+     or logos of any Contributor (except as may be necessary to comply with
+     the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+     No Contributor makes additional grants as a result of Your choice to
+     distribute the Covered Software under a subsequent version of this
+     License (see Section 10.2) or under the terms of a Secondary License (if
+     permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+     Each Contributor represents that the Contributor believes its
+     Contributions are its original creation(s) or it has sufficient rights to
+     grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+     This License is not intended to limit any rights You have under
+     applicable copyright doctrines of fair use, fair dealing, or other
+     equivalents.
+
+2.7. Conditions
+
+     Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+     Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+     All distribution of Covered Software in Source Code Form, including any
+     Modifications that You create or to which You contribute, must be under
+     the terms of this License. You must inform recipients that the Source
+     Code Form of the Covered Software is governed by the terms of this
+     License, and how they can obtain a copy of this License. You may not
+     attempt to alter or restrict the recipients' rights in the Source Code
+     Form.
+
+3.2. Distribution of Executable Form
+
+     If You distribute Covered Software in Executable Form then:
+
+     a. such Covered Software must also be made available in Source Code Form,
+        as described in Section 3.1, and You must inform recipients of the
+        Executable Form how they can obtain a copy of such Source Code Form by
+        reasonable means in a timely manner, at a charge no more than the cost
+        of distribution to the recipient; and
+
+     b. You may distribute such Executable Form under the terms of this
+        License, or sublicense it under different terms, provided that the
+        license for the Executable Form does not attempt to limit or alter the
+        recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+     You may create and distribute a Larger Work under terms of Your choice,
+     provided that You also comply with the requirements of this License for
+     the Covered Software. If the Larger Work is a combination of Covered
+     Software with a work governed by one or more Secondary Licenses, and the
+     Covered Software is not Incompatible With Secondary Licenses, this
+     License permits You to additionally distribute such Covered Software
+     under the terms of such Secondary License(s), so that the recipient of
+     the Larger Work may, at their option, further distribute the Covered
+     Software under the terms of either this License or such Secondary
+     License(s).
+
+3.4. Notices
+
+     You may not remove or alter the substance of any license notices
+     (including copyright notices, patent notices, disclaimers of warranty, or
+     limitations of liability) contained within the Source Code Form of the
+     Covered Software, except that You may alter any license notices to the
+     extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+     You may choose to offer, and to charge a fee for, warranty, support,
+     indemnity or liability obligations to one or more recipients of Covered
+     Software. However, You may do so only on Your own behalf, and not on
+     behalf of any Contributor. You must make it absolutely clear that any
+     such warranty, support, indemnity, or liability obligation is offered by
+     You alone, and You hereby agree to indemnify every Contributor for any
+     liability incurred by such Contributor as a result of warranty, support,
+     indemnity or liability terms You offer. You may include additional
+     disclaimers of warranty and limitations of liability specific to any
+     jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+   If it is impossible for You to comply with any of the terms of this License
+   with respect to some or all of the Covered Software due to statute,
+   judicial order, or regulation then You must: (a) comply with the terms of
+   this License to the maximum extent possible; and (b) describe the
+   limitations and the code they affect. Such description must be placed in a
+   text file included with all distributions of the Covered Software under
+   this License. Except to the extent prohibited by statute or regulation,
+   such description must be sufficiently detailed for a recipient of ordinary
+   skill to be able to understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+     fail to comply with any of its terms. However, if You become compliant,
+     then the rights granted under this License from a particular Contributor
+     are reinstated (a) provisionally, unless and until such Contributor
+     explicitly and finally terminates Your grants, and (b) on an ongoing
+     basis, if such Contributor fails to notify You of the non-compliance by
+     some reasonable means prior to 60 days after You have come back into
+     compliance. Moreover, Your grants from a particular Contributor are
+     reinstated on an ongoing basis if such Contributor notifies You of the
+     non-compliance by some reasonable means, this is the first time You have
+     received notice of non-compliance with this License from such
+     Contributor, and You become compliant prior to 30 days after Your receipt
+     of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+     infringement claim (excluding declaratory judgment actions,
+     counter-claims, and cross-claims) alleging that a Contributor Version
+     directly or indirectly infringes any patent, then the rights granted to
+     You by any and all Contributors for the Covered Software under Section
+     2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+     license agreements (excluding distributors and resellers) which have been
+     validly granted by You or Your distributors under this License prior to
+     termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+   Covered Software is provided under this License on an "as is" basis,
+   without warranty of any kind, either expressed, implied, or statutory,
+   including, without limitation, warranties that the Covered Software is free
+   of defects, merchantable, fit for a particular purpose or non-infringing.
+   The entire risk as to the quality and performance of the Covered Software
+   is with You. Should any Covered Software prove defective in any respect,
+   You (not any Contributor) assume the cost of any necessary servicing,
+   repair, or correction. This disclaimer of warranty constitutes an essential
+   part of this License. No use of  any Covered Software is authorized under
+   this License except under this disclaimer.
+
+7. Limitation of Liability
+
+   Under no circumstances and under no legal theory, whether tort (including
+   negligence), contract, or otherwise, shall any Contributor, or anyone who
+   distributes Covered Software as permitted above, be liable to You for any
+   direct, indirect, special, incidental, or consequential damages of any
+   character including, without limitation, damages for lost profits, loss of
+   goodwill, work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses, even if such party shall have been
+   informed of the possibility of such damages. This limitation of liability
+   shall not apply to liability for death or personal injury resulting from
+   such party's negligence to the extent applicable law prohibits such
+   limitation. Some jurisdictions do not allow the exclusion or limitation of
+   incidental or consequential damages, so this exclusion and limitation may
+   not apply to You.
+
+8. Litigation
+
+   Any litigation relating to this License may be brought only in the courts
+   of a jurisdiction where the defendant maintains its principal place of
+   business and such litigation shall be governed by laws of that
+   jurisdiction, without reference to its conflict-of-law provisions. Nothing
+   in this Section shall prevent a party's ability to bring cross-claims or
+   counter-claims.
+
+9. Miscellaneous
+
+   This License represents the complete agreement concerning the subject
+   matter hereof. If any provision of this License is held to be
+   unenforceable, such provision shall be reformed only to the extent
+   necessary to make it enforceable. Any law or regulation which provides that
+   the language of a contract shall be construed against the drafter shall not
+   be used to construe this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+      Mozilla Foundation is the license steward. Except as provided in Section
+      10.3, no one other than the license steward has the right to modify or
+      publish new versions of this License. Each version will be given a
+      distinguishing version number.
+
+10.2. Effect of New Versions
+
+      You may distribute the Covered Software under the terms of the version
+      of the License under which You originally received the Covered Software,
+      or under the terms of any subsequent version published by the license
+      steward.
+
+10.3. Modified Versions
+
+      If you create software not governed by this License, and you want to
+      create a new license for such software, you may create and use a
+      modified version of this License if you rename the license and remove
+      any references to the name of the license steward (except to note that
+      such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+      Licenses If You choose to distribute Source Code Form that is
+      Incompatible With Secondary Licenses under the terms of this version of
+      the License, the notice described in Exhibit B of this License must be
+      attached.
+
+Exhibit A - Source Code Form License Notice
+
+      This Source Code Form is subject to the
+      terms of the Mozilla Public License, v.
+      2.0. If a copy of the MPL was not
+      distributed with this file, You can
+      obtain one at
+      http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file,
+then You may include the notice in a location (such as a LICENSE file in a
+relevant directory) where a recipient would be likely to look for such a
+notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+
+      This Source Code Form is "Incompatible
+      With Secondary Licenses", as defined by
+      the Mozilla Public License, v. 2.0.

vendor/github.com/hashicorp/golang-lru/simplelru/lru.go

@@ -0,0 +1,161 @@
+package simplelru
+
+import (
+	"container/list"
+	"errors"
+)
+
+// EvictCallback is used to get a callback when a cache entry is evicted
+type EvictCallback func(key interface{}, value interface{})
+
+// LRU implements a non-thread safe fixed size LRU cache
+type LRU struct {
+	size      int
+	evictList *list.List
+	items     map[interface{}]*list.Element
+	onEvict   EvictCallback
+}
+
+// entry is used to hold a value in the evictList
+type entry struct {
+	key   interface{}
+	value interface{}
+}
+
+// NewLRU constructs an LRU of the given size
+func NewLRU(size int, onEvict EvictCallback) (*LRU, error) {
+	if size <= 0 {
+		return nil, errors.New("Must provide a positive size")
+	}
+	c := &LRU{
+		size:      size,
+		evictList: list.New(),
+		items:     make(map[interface{}]*list.Element),
+		onEvict:   onEvict,
+	}
+	return c, nil
+}
+
+// Purge is used to completely clear the cache.
+func (c *LRU) Purge() {
+	for k, v := range c.items {
+		if c.onEvict != nil {
+			c.onEvict(k, v.Value.(*entry).value)
+		}
+		delete(c.items, k)
+	}
+	c.evictList.Init()
+}
+
+// Add adds a value to the cache.  Returns true if an eviction occurred.
+func (c *LRU) Add(key, value interface{}) (evicted bool) {
+	// Check for existing item
+	if ent, ok := c.items[key]; ok {
+		c.evictList.MoveToFront(ent)
+		ent.Value.(*entry).value = value
+		return false
+	}
+
+	// Add new item
+	ent := &entry{key, value}
+	entry := c.evictList.PushFront(ent)
+	c.items[key] = entry
+
+	evict := c.evictList.Len() > c.size
+	// Verify size not exceeded
+	if evict {
+		c.removeOldest()
+	}
+	return evict
+}
+
+// Get looks up a key's value from the cache.
+func (c *LRU) Get(key interface{}) (value interface{}, ok bool) {
+	if ent, ok := c.items[key]; ok {
+		c.evictList.MoveToFront(ent)
+		return ent.Value.(*entry).value, true
+	}
+	return
+}
+
+// Contains checks if a key is in the cache, without updating the recent-ness
+// or deleting it for being stale.
+func (c *LRU) Contains(key interface{}) (ok bool) {
+	_, ok = c.items[key]
+	return ok
+}
+
+// Peek returns the key value (or undefined if not found) without updating
+// the "recently used"-ness of the key.
+func (c *LRU) Peek(key interface{}) (value interface{}, ok bool) {
+	var ent *list.Element
+	if ent, ok = c.items[key]; ok {
+		return ent.Value.(*entry).value, true
+	}
+	return nil, ok
+}
+
+// Remove removes the provided key from the cache, returning if the
+// key was contained.
+func (c *LRU) Remove(key interface{}) (present bool) {
+	if ent, ok := c.items[key]; ok {
+		c.removeElement(ent)
+		return true
+	}
+	return false
+}
+
+// RemoveOldest removes the oldest item from the cache.
+func (c *LRU) RemoveOldest() (key interface{}, value interface{}, ok bool) {
+	ent := c.evictList.Back()
+	if ent != nil {
+		c.removeElement(ent)
+		kv := ent.Value.(*entry)
+		return kv.key, kv.value, true
+	}
+	return nil, nil, false
+}
+
+// GetOldest returns the oldest entry
+func (c *LRU) GetOldest() (key interface{}, value interface{}, ok bool) {
+	ent := c.evictList.Back()
+	if ent != nil {
+		kv := ent.Value.(*entry)
+		return kv.key, kv.value, true
+	}
+	return nil, nil, false
+}
+
+// Keys returns a slice of the keys in the cache, from oldest to newest.
+func (c *LRU) Keys() []interface{} {
+	keys := make([]interface{}, len(c.items))
+	i := 0
+	for ent := c.evictList.Back(); ent != nil; ent = ent.Prev() {
+		keys[i] = ent.Value.(*entry).key
+		i++
+	}
+	return keys
+}
+
+// Len returns the number of items in the cache.
+func (c *LRU) Len() int {
+	return c.evictList.Len()
+}
+
+// removeOldest removes the oldest item from the cache.
+func (c *LRU) removeOldest() {
+	ent := c.evictList.Back()
+	if ent != nil {
+		c.removeElement(ent)
+	}
+}
+
+// removeElement is used to remove a given list element from the cache
+func (c *LRU) removeElement(e *list.Element) {
+	c.evictList.Remove(e)
+	kv := e.Value.(*entry)
+	delete(c.items, kv.key)
+	if c.onEvict != nil {
+		c.onEvict(kv.key, kv.value)
+	}
+}

vendor/github.com/hashicorp/golang-lru/simplelru/lru_interface.go

@@ -0,0 +1,36 @@
+package simplelru
+
+// LRUCache is the interface for simple LRU cache.
+type LRUCache interface {
+	// Adds a value to the cache, returns true if an eviction occurred and
+	// updates the "recently used"-ness of the key.
+	Add(key, value interface{}) bool
+
+	// Returns key's value from the cache and
+	// updates the "recently used"-ness of the key. #value, isFound
+	Get(key interface{}) (value interface{}, ok bool)
+
+	// Check if a key exsists in cache without updating the recent-ness.
+	Contains(key interface{}) (ok bool)
+
+	// Returns key's value without updating the "recently used"-ness of the key.
+	Peek(key interface{}) (value interface{}, ok bool)
+
+	// Removes a key from the cache.
+	Remove(key interface{}) bool
+
+	// Removes the oldest entry from cache.
+	RemoveOldest() (interface{}, interface{}, bool)
+
+	// Returns the oldest entry from the cache. #key, value, isFound
+	GetOldest() (interface{}, interface{}, bool)
+
+	// Returns a slice of the keys in the cache, from oldest to newest.
+	Keys() []interface{}
+
+	// Returns the number of items in the cache.
+	Len() int
+
+	// Clear all cache entries
+	Purge()
+}

vendor/github.com/matttproud/golang_protobuf_extensions/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/matttproud/golang_protobuf_extensions/NOTICE

@@ -0,0 +1 @@
+Copyright 2012 Matt T. Proud (matt.proud@gmail.com)

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore

@@ -0,0 +1 @@
+cover.dat

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile

@@ -0,0 +1,7 @@
+all:
+
+cover:
+	go test -cover -v -coverprofile=cover.dat ./...
+	go tool cover -func cover.dat
+
+.PHONY: cover

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go

@@ -0,0 +1,75 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"errors"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+var errInvalidVarint = errors.New("invalid varint32 encountered")
+
+// ReadDelimited decodes a message from the provided length-delimited stream,
+// where the length is encoded as 32-bit varint prefix to the message body.
+// It returns the total number of bytes read and any applicable error.  This is
+// roughly equivalent to the companion Java API's
+// MessageLite#parseDelimitedFrom.  As per the reader contract, this function
+// calls r.Read repeatedly as required until exactly one message including its
+// prefix is read and decoded (or an error has occurred).  The function never
+// reads more bytes from the stream than required.  The function never returns
+// an error if a message has been read and decoded correctly, even if the end
+// of the stream has been reached in doing so.  In that case, any subsequent
+// calls return (0, io.EOF).
+func ReadDelimited(r io.Reader, m proto.Message) (n int, err error) {
+	// Per AbstractParser#parsePartialDelimitedFrom with
+	// CodedInputStream#readRawVarint32.
+	var headerBuf [binary.MaxVarintLen32]byte
+	var bytesRead, varIntBytes int
+	var messageLength uint64
+	for varIntBytes == 0 { // i.e. no varint has been decoded yet.
+		if bytesRead >= len(headerBuf) {
+			return bytesRead, errInvalidVarint
+		}
+		// We have to read byte by byte here to avoid reading more bytes
+		// than required. Each read byte is appended to what we have
+		// read before.
+		newBytesRead, err := r.Read(headerBuf[bytesRead : bytesRead+1])
+		if newBytesRead == 0 {
+			if err != nil {
+				return bytesRead, err
+			}
+			// A Reader should not return (0, nil), but if it does,
+			// it should be treated as no-op (according to the
+			// Reader contract). So let's go on...
+			continue
+		}
+		bytesRead += newBytesRead
+		// Now present everything read so far to the varint decoder and
+		// see if a varint can be decoded already.
+		messageLength, varIntBytes = proto.DecodeVarint(headerBuf[:bytesRead])
+	}
+
+	messageBuf := make([]byte, messageLength)
+	newBytesRead, err := io.ReadFull(r, messageBuf)
+	bytesRead += newBytesRead
+	if err != nil {
+		return bytesRead, err
+	}
+
+	return bytesRead, proto.Unmarshal(messageBuf, m)
+}

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/doc.go

@@ -0,0 +1,16 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package pbutil provides record length-delimited Protocol Buffer streaming.
+package pbutil

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go

@@ -0,0 +1,46 @@
+// Copyright 2013 Matt T. Proud
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pbutil
+
+import (
+	"encoding/binary"
+	"io"
+
+	"github.com/golang/protobuf/proto"
+)
+
+// WriteDelimited encodes and dumps a message to the provided writer prefixed
+// with a 32-bit varint indicating the length of the encoded message, producing
+// a length-delimited record stream, which can be used to chain together
+// encoded messages of the same type together in a file.  It returns the total
+// number of bytes written and any applicable error.  This is roughly
+// equivalent to the companion Java API's MessageLite#writeDelimitedTo.
+func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
+	buffer, err := proto.Marshal(m)
+	if err != nil {
+		return 0, err
+	}
+
+	var buf [binary.MaxVarintLen32]byte
+	encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
+
+	sync, err := w.Write(buf[:encodedLength])
+	if err != nil {
+		return sync, err
+	}
+
+	n, err = w.Write(buffer)
+	return n + sync, err
+}

vendor/github.com/prometheus/client_golang/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Work" shall mean the work of authorship, whether in Source or
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+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
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+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+      Work and such Derivative Works in Source or Object form.
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+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
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+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
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+
+   END OF TERMS AND CONDITIONS
+
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+
+      To apply the Apache License to your work, attach the following
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+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/github.com/prometheus/client_golang/NOTICE

@@ -0,0 +1,23 @@
+Prometheus instrumentation library for Go applications
+Copyright 2012-2015 The Prometheus Authors
+
+This product includes software developed at
+SoundCloud Ltd. (http://soundcloud.com/).
+
+
+The following components are included in this product:
+
+perks - a fork of https://github.com/bmizerany/perks
+https://github.com/beorn7/perks
+Copyright 2013-2015 Blake Mizerany, Björn Rabenstein
+See https://github.com/beorn7/perks/blob/master/README.md for license details.
+
+Go support for Protocol Buffers - Google's data interchange format
+http://github.com/golang/protobuf/
+Copyright 2010 The Go Authors
+See source code for license details.
+
+Support for streaming Protocol Buffer messages for the Go language (golang).
+https://github.com/matttproud/golang_protobuf_extensions
+Copyright 2013 Matt T. Proud
+Licensed under the Apache License, Version 2.0

vendor/github.com/prometheus/client_golang/prometheus/.gitignore

@@ -0,0 +1 @@
+command-line-arguments.test

vendor/github.com/prometheus/client_golang/prometheus/README.md

@@ -0,0 +1 @@
+See [![go-doc](https://godoc.org/github.com/prometheus/client_golang/prometheus?status.svg)](https://godoc.org/github.com/prometheus/client_golang/prometheus).

vendor/github.com/prometheus/client_golang/prometheus/collector.go

@@ -0,0 +1,120 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Collector is the interface implemented by anything that can be used by
+// Prometheus to collect metrics. A Collector has to be registered for
+// collection. See Registerer.Register.
+//
+// The stock metrics provided by this package (Gauge, Counter, Summary,
+// Histogram, Untyped) are also Collectors (which only ever collect one metric,
+// namely itself). An implementer of Collector may, however, collect multiple
+// metrics in a coordinated fashion and/or create metrics on the fly. Examples
+// for collectors already implemented in this library are the metric vectors
+// (i.e. collection of multiple instances of the same Metric but with different
+// label values) like GaugeVec or SummaryVec, and the ExpvarCollector.
+type Collector interface {
+	// Describe sends the super-set of all possible descriptors of metrics
+	// collected by this Collector to the provided channel and returns once
+	// the last descriptor has been sent. The sent descriptors fulfill the
+	// consistency and uniqueness requirements described in the Desc
+	// documentation.
+	//
+	// It is valid if one and the same Collector sends duplicate
+	// descriptors. Those duplicates are simply ignored. However, two
+	// different Collectors must not send duplicate descriptors.
+	//
+	// Sending no descriptor at all marks the Collector as “unchecked”,
+	// i.e. no checks will be performed at registration time, and the
+	// Collector may yield any Metric it sees fit in its Collect method.
+	//
+	// This method idempotently sends the same descriptors throughout the
+	// lifetime of the Collector. It may be called concurrently and
+	// therefore must be implemented in a concurrency safe way.
+	//
+	// If a Collector encounters an error while executing this method, it
+	// must send an invalid descriptor (created with NewInvalidDesc) to
+	// signal the error to the registry.
+	Describe(chan<- *Desc)
+	// Collect is called by the Prometheus registry when collecting
+	// metrics. The implementation sends each collected metric via the
+	// provided channel and returns once the last metric has been sent. The
+	// descriptor of each sent metric is one of those returned by Describe
+	// (unless the Collector is unchecked, see above). Returned metrics that
+	// share the same descriptor must differ in their variable label
+	// values.
+	//
+	// This method may be called concurrently and must therefore be
+	// implemented in a concurrency safe way. Blocking occurs at the expense
+	// of total performance of rendering all registered metrics. Ideally,
+	// Collector implementations support concurrent readers.
+	Collect(chan<- Metric)
+}
+
+// DescribeByCollect is a helper to implement the Describe method of a custom
+// Collector. It collects the metrics from the provided Collector and sends
+// their descriptors to the provided channel.
+//
+// If a Collector collects the same metrics throughout its lifetime, its
+// Describe method can simply be implemented as:
+//
+//   func (c customCollector) Describe(ch chan<- *Desc) {
+//   	DescribeByCollect(c, ch)
+//   }
+//
+// However, this will not work if the metrics collected change dynamically over
+// the lifetime of the Collector in a way that their combined set of descriptors
+// changes as well. The shortcut implementation will then violate the contract
+// of the Describe method. If a Collector sometimes collects no metrics at all
+// (for example vectors like CounterVec, GaugeVec, etc., which only collect
+// metrics after a metric with a fully specified label set has been accessed),
+// it might even get registered as an unchecked Collecter (cf. the Register
+// method of the Registerer interface). Hence, only use this shortcut
+// implementation of Describe if you are certain to fulfill the contract.
+//
+// The Collector example demonstrates a use of DescribeByCollect.
+func DescribeByCollect(c Collector, descs chan<- *Desc) {
+	metrics := make(chan Metric)
+	go func() {
+		c.Collect(metrics)
+		close(metrics)
+	}()
+	for m := range metrics {
+		descs <- m.Desc()
+	}
+}
+
+// selfCollector implements Collector for a single Metric so that the Metric
+// collects itself. Add it as an anonymous field to a struct that implements
+// Metric, and call init with the Metric itself as an argument.
+type selfCollector struct {
+	self Metric
+}
+
+// init provides the selfCollector with a reference to the metric it is supposed
+// to collect. It is usually called within the factory function to create a
+// metric. See example.
+func (c *selfCollector) init(self Metric) {
+	c.self = self
+}
+
+// Describe implements Collector.
+func (c *selfCollector) Describe(ch chan<- *Desc) {
+	ch <- c.self.Desc()
+}
+
+// Collect implements Collector.
+func (c *selfCollector) Collect(ch chan<- Metric) {
+	ch <- c.self
+}

vendor/github.com/prometheus/client_golang/prometheus/counter.go

@@ -0,0 +1,277 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"math"
+	"sync/atomic"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Counter is a Metric that represents a single numerical value that only ever
+// goes up. That implies that it cannot be used to count items whose number can
+// also go down, e.g. the number of currently running goroutines. Those
+// "counters" are represented by Gauges.
+//
+// A Counter is typically used to count requests served, tasks completed, errors
+// occurred, etc.
+//
+// To create Counter instances, use NewCounter.
+type Counter interface {
+	Metric
+	Collector
+
+	// Inc increments the counter by 1. Use Add to increment it by arbitrary
+	// non-negative values.
+	Inc()
+	// Add adds the given value to the counter. It panics if the value is <
+	// 0.
+	Add(float64)
+}
+
+// CounterOpts is an alias for Opts. See there for doc comments.
+type CounterOpts Opts
+
+// NewCounter creates a new Counter based on the provided CounterOpts.
+//
+// The returned implementation tracks the counter value in two separate
+// variables, a float64 and a uint64. The latter is used to track calls of the
+// Inc method and calls of the Add method with a value that can be represented
+// as a uint64. This allows atomic increments of the counter with optimal
+// performance. (It is common to have an Inc call in very hot execution paths.)
+// Both internal tracking values are added up in the Write method. This has to
+// be taken into account when it comes to precision and overflow behavior.
+func NewCounter(opts CounterOpts) Counter {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &counter{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type counter struct {
+	// valBits contains the bits of the represented float64 value, while
+	// valInt stores values that are exact integers. Both have to go first
+	// in the struct to guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+	valInt  uint64
+
+	selfCollector
+	desc *Desc
+
+	labelPairs []*dto.LabelPair
+}
+
+func (c *counter) Desc() *Desc {
+	return c.desc
+}
+
+func (c *counter) Add(v float64) {
+	if v < 0 {
+		panic(errors.New("counter cannot decrease in value"))
+	}
+	ival := uint64(v)
+	if float64(ival) == v {
+		atomic.AddUint64(&c.valInt, ival)
+		return
+	}
+
+	for {
+		oldBits := atomic.LoadUint64(&c.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&c.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (c *counter) Inc() {
+	atomic.AddUint64(&c.valInt, 1)
+}
+
+func (c *counter) Write(out *dto.Metric) error {
+	fval := math.Float64frombits(atomic.LoadUint64(&c.valBits))
+	ival := atomic.LoadUint64(&c.valInt)
+	val := fval + float64(ival)
+
+	return populateMetric(CounterValue, val, c.labelPairs, out)
+}
+
+// CounterVec is a Collector that bundles a set of Counters that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. number of HTTP requests, partitioned by response code and
+// method). Create instances with NewCounterVec.
+type CounterVec struct {
+	*metricVec
+}
+
+// NewCounterVec creates a new CounterVec based on the provided CounterOpts and
+// partitioned by the given label names.
+func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &CounterVec{
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &counter{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Counter for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Counter is created.
+//
+// It is possible to call this method without using the returned Counter to only
+// create the new Counter but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Counter for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Counter from the CounterVec. In that case,
+// the Counter will still exist, but it will not be exported anymore, even if a
+// Counter with the same label values is created later.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Counter for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Counter is created. Implications of
+// creating a Counter without using it and keeping the Counter for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
+	if metric != nil {
+		return metric.(Counter), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
+	c, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *CounterVec) With(labels Labels) Counter {
+	c, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return c
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the CounterVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &CounterVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// CounterFunc is a Counter whose value is determined at collect time by calling a
+// provided function.
+//
+// To create CounterFunc instances, use NewCounterFunc.
+type CounterFunc interface {
+	Metric
+	Collector
+}
+
+// NewCounterFunc creates a new CounterFunc based on the provided
+// CounterOpts. The value reported is determined by calling the given function
+// from within the Write method. Take into account that metric collection may
+// happen concurrently. If that results in concurrent calls to Write, like in
+// the case where a CounterFunc is directly registered with Prometheus, the
+// provided function must be concurrency-safe. The function should also honor
+// the contract for a Counter (values only go up, not down), but compliance will
+// not be checked.
+func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), CounterValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -0,0 +1,184 @@
+// Copyright 2016 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Desc is the descriptor used by every Prometheus Metric. It is essentially
+// the immutable meta-data of a Metric. The normal Metric implementations
+// included in this package manage their Desc under the hood. Users only have to
+// deal with Desc if they use advanced features like the ExpvarCollector or
+// custom Collectors and Metrics.
+//
+// Descriptors registered with the same registry have to fulfill certain
+// consistency and uniqueness criteria if they share the same fully-qualified
+// name: They must have the same help string and the same label names (aka label
+// dimensions) in each, constLabels and variableLabels, but they must differ in
+// the values of the constLabels.
+//
+// Descriptors that share the same fully-qualified names and the same label
+// values of their constLabels are considered equal.
+//
+// Use NewDesc to create new Desc instances.
+type Desc struct {
+	// fqName has been built from Namespace, Subsystem, and Name.
+	fqName string
+	// help provides some helpful information about this metric.
+	help string
+	// constLabelPairs contains precalculated DTO label pairs based on
+	// the constant labels.
+	constLabelPairs []*dto.LabelPair
+	// VariableLabels contains names of labels for which the metric
+	// maintains variable values.
+	variableLabels []string
+	// id is a hash of the values of the ConstLabels and fqName. This
+	// must be unique among all registered descriptors and can therefore be
+	// used as an identifier of the descriptor.
+	id uint64
+	// dimHash is a hash of the label names (preset and variable) and the
+	// Help string. Each Desc with the same fqName must have the same
+	// dimHash.
+	dimHash uint64
+	// err is an error that occurred during construction. It is reported on
+	// registration time.
+	err error
+}
+
+// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc
+// and will be reported on registration time. variableLabels and constLabels can
+// be nil if no such labels should be set. fqName must not be empty.
+//
+// variableLabels only contain the label names. Their label values are variable
+// and therefore not part of the Desc. (They are managed within the Metric.)
+//
+// For constLabels, the label values are constant. Therefore, they are fully
+// specified in the Desc. See the Collector example for a usage pattern.
+func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
+	d := &Desc{
+		fqName:         fqName,
+		help:           help,
+		variableLabels: variableLabels,
+	}
+	if !model.IsValidMetricName(model.LabelValue(fqName)) {
+		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
+		return d
+	}
+	// labelValues contains the label values of const labels (in order of
+	// their sorted label names) plus the fqName (at position 0).
+	labelValues := make([]string, 1, len(constLabels)+1)
+	labelValues[0] = fqName
+	labelNames := make([]string, 0, len(constLabels)+len(variableLabels))
+	labelNameSet := map[string]struct{}{}
+	// First add only the const label names and sort them...
+	for labelName := range constLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
+			return d
+		}
+		labelNames = append(labelNames, labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	sort.Strings(labelNames)
+	// ... so that we can now add const label values in the order of their names.
+	for _, labelName := range labelNames {
+		labelValues = append(labelValues, constLabels[labelName])
+	}
+	// Validate the const label values. They can't have a wrong cardinality, so
+	// use in len(labelValues) as expectedNumberOfValues.
+	if err := validateLabelValues(labelValues, len(labelValues)); err != nil {
+		d.err = err
+		return d
+	}
+	// Now add the variable label names, but prefix them with something that
+	// cannot be in a regular label name. That prevents matching the label
+	// dimension with a different mix between preset and variable labels.
+	for _, labelName := range variableLabels {
+		if !checkLabelName(labelName) {
+			d.err = fmt.Errorf("%q is not a valid label name for metric %q", labelName, fqName)
+			return d
+		}
+		labelNames = append(labelNames, "$"+labelName)
+		labelNameSet[labelName] = struct{}{}
+	}
+	if len(labelNames) != len(labelNameSet) {
+		d.err = errors.New("duplicate label names")
+		return d
+	}
+
+	vh := hashNew()
+	for _, val := range labelValues {
+		vh = hashAdd(vh, val)
+		vh = hashAddByte(vh, separatorByte)
+	}
+	d.id = vh
+	// Sort labelNames so that order doesn't matter for the hash.
+	sort.Strings(labelNames)
+	// Now hash together (in this order) the help string and the sorted
+	// label names.
+	lh := hashNew()
+	lh = hashAdd(lh, help)
+	lh = hashAddByte(lh, separatorByte)
+	for _, labelName := range labelNames {
+		lh = hashAdd(lh, labelName)
+		lh = hashAddByte(lh, separatorByte)
+	}
+	d.dimHash = lh
+
+	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
+	for n, v := range constLabels {
+		d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{
+			Name:  proto.String(n),
+			Value: proto.String(v),
+		})
+	}
+	sort.Sort(labelPairSorter(d.constLabelPairs))
+	return d
+}
+
+// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the
+// provided error set. If a collector returning such a descriptor is registered,
+// registration will fail with the provided error. NewInvalidDesc can be used by
+// a Collector to signal inability to describe itself.
+func NewInvalidDesc(err error) *Desc {
+	return &Desc{
+		err: err,
+	}
+}
+
+func (d *Desc) String() string {
+	lpStrings := make([]string, 0, len(d.constLabelPairs))
+	for _, lp := range d.constLabelPairs {
+		lpStrings = append(
+			lpStrings,
+			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
+		)
+	}
+	return fmt.Sprintf(
+		"Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}",
+		d.fqName,
+		d.help,
+		strings.Join(lpStrings, ","),
+		d.variableLabels,
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/doc.go

@@ -0,0 +1,201 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package prometheus is the core instrumentation package. It provides metrics
+// primitives to instrument code for monitoring. It also offers a registry for
+// metrics. Sub-packages allow to expose the registered metrics via HTTP
+// (package promhttp) or push them to a Pushgateway (package push). There is
+// also a sub-package promauto, which provides metrics constructors with
+// automatic registration.
+//
+// All exported functions and methods are safe to be used concurrently unless
+// specified otherwise.
+//
+// A Basic Example
+//
+// As a starting point, a very basic usage example:
+//
+//    package main
+//
+//    import (
+//    	"log"
+//    	"net/http"
+//
+//    	"github.com/prometheus/client_golang/prometheus"
+//    	"github.com/prometheus/client_golang/prometheus/promhttp"
+//    )
+//
+//    var (
+//    	cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{
+//    		Name: "cpu_temperature_celsius",
+//    		Help: "Current temperature of the CPU.",
+//    	})
+//    	hdFailures = prometheus.NewCounterVec(
+//    		prometheus.CounterOpts{
+//    			Name: "hd_errors_total",
+//    			Help: "Number of hard-disk errors.",
+//    		},
+//    		[]string{"device"},
+//    	)
+//    )
+//
+//    func init() {
+//    	// Metrics have to be registered to be exposed:
+//    	prometheus.MustRegister(cpuTemp)
+//    	prometheus.MustRegister(hdFailures)
+//    }
+//
+//    func main() {
+//    	cpuTemp.Set(65.3)
+//    	hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
+//
+//    	// The Handler function provides a default handler to expose metrics
+//    	// via an HTTP server. "/metrics" is the usual endpoint for that.
+//    	http.Handle("/metrics", promhttp.Handler())
+//    	log.Fatal(http.ListenAndServe(":8080", nil))
+//    }
+//
+//
+// This is a complete program that exports two metrics, a Gauge and a Counter,
+// the latter with a label attached to turn it into a (one-dimensional) vector.
+//
+// Metrics
+//
+// The number of exported identifiers in this package might appear a bit
+// overwhelming. However, in addition to the basic plumbing shown in the example
+// above, you only need to understand the different metric types and their
+// vector versions for basic usage. Furthermore, if you are not concerned with
+// fine-grained control of when and how to register metrics with the registry,
+// have a look at the promauto package, which will effectively allow you to
+// ignore registration altogether in simple cases.
+//
+// Above, you have already touched the Counter and the Gauge. There are two more
+// advanced metric types: the Summary and Histogram. A more thorough description
+// of those four metric types can be found in the Prometheus docs:
+// https://prometheus.io/docs/concepts/metric_types/
+//
+// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the
+// Prometheus server not to assume anything about its type.
+//
+// In addition to the fundamental metric types Gauge, Counter, Summary,
+// Histogram, and Untyped, a very important part of the Prometheus data model is
+// the partitioning of samples along dimensions called labels, which results in
+// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec,
+// HistogramVec, and UntypedVec.
+//
+// While only the fundamental metric types implement the Metric interface, both
+// the metrics and their vector versions implement the Collector interface. A
+// Collector manages the collection of a number of Metrics, but for convenience,
+// a Metric can also “collect itself”. Note that Gauge, Counter, Summary,
+// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec,
+// SummaryVec, HistogramVec, and UntypedVec are not.
+//
+// To create instances of Metrics and their vector versions, you need a suitable
+// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, HistogramOpts, or
+// UntypedOpts.
+//
+// Custom Collectors and constant Metrics
+//
+// While you could create your own implementations of Metric, most likely you
+// will only ever implement the Collector interface on your own. At a first
+// glance, a custom Collector seems handy to bundle Metrics for common
+// registration (with the prime example of the different metric vectors above,
+// which bundle all the metrics of the same name but with different labels).
+//
+// There is a more involved use case, too: If you already have metrics
+// available, created outside of the Prometheus context, you don't need the
+// interface of the various Metric types. You essentially want to mirror the
+// existing numbers into Prometheus Metrics during collection. An own
+// implementation of the Collector interface is perfect for that. You can create
+// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and
+// NewConstSummary (and their respective Must… versions). That will happen in
+// the Collect method. The Describe method has to return separate Desc
+// instances, representative of the “throw-away” metrics to be created later.
+// NewDesc comes in handy to create those Desc instances. Alternatively, you
+// could return no Desc at all, which will marke the Collector “unchecked”.  No
+// checks are porformed at registration time, but metric consistency will still
+// be ensured at scrape time, i.e. any inconsistencies will lead to scrape
+// errors. Thus, with unchecked Collectors, the responsibility to not collect
+// metrics that lead to inconsistencies in the total scrape result lies with the
+// implementer of the Collector. While this is not a desirable state, it is
+// sometimes necessary. The typical use case is a situatios where the exact
+// metrics to be returned by a Collector cannot be predicted at registration
+// time, but the implementer has sufficient knowledge of the whole system to
+// guarantee metric consistency.
+//
+// The Collector example illustrates the use case. You can also look at the
+// source code of the processCollector (mirroring process metrics), the
+// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar
+// metrics) as examples that are used in this package itself.
+//
+// If you just need to call a function to get a single float value to collect as
+// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
+// shortcuts.
+//
+// Advanced Uses of the Registry
+//
+// While MustRegister is the by far most common way of registering a Collector,
+// sometimes you might want to handle the errors the registration might cause.
+// As suggested by the name, MustRegister panics if an error occurs. With the
+// Register function, the error is returned and can be handled.
+//
+// An error is returned if the registered Collector is incompatible or
+// inconsistent with already registered metrics. The registry aims for
+// consistency of the collected metrics according to the Prometheus data model.
+// Inconsistencies are ideally detected at registration time, not at collect
+// time. The former will usually be detected at start-up time of a program,
+// while the latter will only happen at scrape time, possibly not even on the
+// first scrape if the inconsistency only becomes relevant later. That is the
+// main reason why a Collector and a Metric have to describe themselves to the
+// registry.
+//
+// So far, everything we did operated on the so-called default registry, as it
+// can be found in the global DefaultRegisterer variable. With NewRegistry, you
+// can create a custom registry, or you can even implement the Registerer or
+// Gatherer interfaces yourself. The methods Register and Unregister work in the
+// same way on a custom registry as the global functions Register and Unregister
+// on the default registry.
+//
+// There are a number of uses for custom registries: You can use registries with
+// special properties, see NewPedanticRegistry. You can avoid global state, as
+// it is imposed by the DefaultRegisterer. You can use multiple registries at
+// the same time to expose different metrics in different ways.  You can use
+// separate registries for testing purposes.
+//
+// Also note that the DefaultRegisterer comes registered with a Collector for Go
+// runtime metrics (via NewGoCollector) and a Collector for process metrics (via
+// NewProcessCollector). With a custom registry, you are in control and decide
+// yourself about the Collectors to register.
+//
+// HTTP Exposition
+//
+// The Registry implements the Gatherer interface. The caller of the Gather
+// method can then expose the gathered metrics in some way. Usually, the metrics
+// are served via HTTP on the /metrics endpoint. That's happening in the example
+// above. The tools to expose metrics via HTTP are in the promhttp sub-package.
+// (The top-level functions in the prometheus package are deprecated.)
+//
+// Pushing to the Pushgateway
+//
+// Function for pushing to the Pushgateway can be found in the push sub-package.
+//
+// Graphite Bridge
+//
+// Functions and examples to push metrics from a Gatherer to Graphite can be
+// found in the graphite sub-package.
+//
+// Other Means of Exposition
+//
+// More ways of exposing metrics can easily be added by following the approaches
+// of the existing implementations.
+package prometheus

vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go

@@ -0,0 +1,119 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"encoding/json"
+	"expvar"
+)
+
+type expvarCollector struct {
+	exports map[string]*Desc
+}
+
+// NewExpvarCollector returns a newly allocated expvar Collector that still has
+// to be registered with a Prometheus registry.
+//
+// An expvar Collector collects metrics from the expvar interface. It provides a
+// quick way to expose numeric values that are already exported via expvar as
+// Prometheus metrics. Note that the data models of expvar and Prometheus are
+// fundamentally different, and that the expvar Collector is inherently slower
+// than native Prometheus metrics. Thus, the expvar Collector is probably great
+// for experiments and prototying, but you should seriously consider a more
+// direct implementation of Prometheus metrics for monitoring production
+// systems.
+//
+// The exports map has the following meaning:
+//
+// The keys in the map correspond to expvar keys, i.e. for every expvar key you
+// want to export as Prometheus metric, you need an entry in the exports
+// map. The descriptor mapped to each key describes how to export the expvar
+// value. It defines the name and the help string of the Prometheus metric
+// proxying the expvar value. The type will always be Untyped.
+//
+// For descriptors without variable labels, the expvar value must be a number or
+// a bool. The number is then directly exported as the Prometheus sample
+// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values
+// that are not numbers or bools are silently ignored.
+//
+// If the descriptor has one variable label, the expvar value must be an expvar
+// map. The keys in the expvar map become the various values of the one
+// Prometheus label. The values in the expvar map must be numbers or bools again
+// as above.
+//
+// For descriptors with more than one variable label, the expvar must be a
+// nested expvar map, i.e. where the values of the topmost map are maps again
+// etc. until a depth is reached that corresponds to the number of labels. The
+// leaves of that structure must be numbers or bools as above to serve as the
+// sample values.
+//
+// Anything that does not fit into the scheme above is silently ignored.
+func NewExpvarCollector(exports map[string]*Desc) Collector {
+	return &expvarCollector{
+		exports: exports,
+	}
+}
+
+// Describe implements Collector.
+func (e *expvarCollector) Describe(ch chan<- *Desc) {
+	for _, desc := range e.exports {
+		ch <- desc
+	}
+}
+
+// Collect implements Collector.
+func (e *expvarCollector) Collect(ch chan<- Metric) {
+	for name, desc := range e.exports {
+		var m Metric
+		expVar := expvar.Get(name)
+		if expVar == nil {
+			continue
+		}
+		var v interface{}
+		labels := make([]string, len(desc.variableLabels))
+		if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil {
+			ch <- NewInvalidMetric(desc, err)
+			continue
+		}
+		var processValue func(v interface{}, i int)
+		processValue = func(v interface{}, i int) {
+			if i >= len(labels) {
+				copiedLabels := append(make([]string, 0, len(labels)), labels...)
+				switch v := v.(type) {
+				case float64:
+					m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...)
+				case bool:
+					if v {
+						m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...)
+					} else {
+						m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...)
+					}
+				default:
+					return
+				}
+				ch <- m
+				return
+			}
+			vm, ok := v.(map[string]interface{})
+			if !ok {
+				return
+			}
+			for lv, val := range vm {
+				labels[i] = lv
+				processValue(val, i+1)
+			}
+		}
+		processValue(v, 0)
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/fnv.go

@@ -0,0 +1,42 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Inline and byte-free variant of hash/fnv's fnv64a.
+
+const (
+	offset64 = 14695981039346656037
+	prime64  = 1099511628211
+)
+
+// hashNew initializies a new fnv64a hash value.
+func hashNew() uint64 {
+	return offset64
+}
+
+// hashAdd adds a string to a fnv64a hash value, returning the updated hash.
+func hashAdd(h uint64, s string) uint64 {
+	for i := 0; i < len(s); i++ {
+		h ^= uint64(s[i])
+		h *= prime64
+	}
+	return h
+}
+
+// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash.
+func hashAddByte(h uint64, b byte) uint64 {
+	h ^= uint64(b)
+	h *= prime64
+	return h
+}

vendor/github.com/prometheus/client_golang/prometheus/gauge.go

@@ -0,0 +1,286 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"math"
+	"sync/atomic"
+	"time"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// Gauge is a Metric that represents a single numerical value that can
+// arbitrarily go up and down.
+//
+// A Gauge is typically used for measured values like temperatures or current
+// memory usage, but also "counts" that can go up and down, like the number of
+// running goroutines.
+//
+// To create Gauge instances, use NewGauge.
+type Gauge interface {
+	Metric
+	Collector
+
+	// Set sets the Gauge to an arbitrary value.
+	Set(float64)
+	// Inc increments the Gauge by 1. Use Add to increment it by arbitrary
+	// values.
+	Inc()
+	// Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary
+	// values.
+	Dec()
+	// Add adds the given value to the Gauge. (The value can be negative,
+	// resulting in a decrease of the Gauge.)
+	Add(float64)
+	// Sub subtracts the given value from the Gauge. (The value can be
+	// negative, resulting in an increase of the Gauge.)
+	Sub(float64)
+
+	// SetToCurrentTime sets the Gauge to the current Unix time in seconds.
+	SetToCurrentTime()
+}
+
+// GaugeOpts is an alias for Opts. See there for doc comments.
+type GaugeOpts Opts
+
+// NewGauge creates a new Gauge based on the provided GaugeOpts.
+//
+// The returned implementation is optimized for a fast Set method. If you have a
+// choice for managing the value of a Gauge via Set vs. Inc/Dec/Add/Sub, pick
+// the former. For example, the Inc method of the returned Gauge is slower than
+// the Inc method of a Counter returned by NewCounter. This matches the typical
+// scenarios for Gauges and Counters, where the former tends to be Set-heavy and
+// the latter Inc-heavy.
+func NewGauge(opts GaugeOpts) Gauge {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	)
+	result := &gauge{desc: desc, labelPairs: desc.constLabelPairs}
+	result.init(result) // Init self-collection.
+	return result
+}
+
+type gauge struct {
+	// valBits contains the bits of the represented float64 value. It has
+	// to go first in the struct to guarantee alignment for atomic
+	// operations.  http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	valBits uint64
+
+	selfCollector
+
+	desc       *Desc
+	labelPairs []*dto.LabelPair
+}
+
+func (g *gauge) Desc() *Desc {
+	return g.desc
+}
+
+func (g *gauge) Set(val float64) {
+	atomic.StoreUint64(&g.valBits, math.Float64bits(val))
+}
+
+func (g *gauge) SetToCurrentTime() {
+	g.Set(float64(time.Now().UnixNano()) / 1e9)
+}
+
+func (g *gauge) Inc() {
+	g.Add(1)
+}
+
+func (g *gauge) Dec() {
+	g.Add(-1)
+}
+
+func (g *gauge) Add(val float64) {
+	for {
+		oldBits := atomic.LoadUint64(&g.valBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + val)
+		if atomic.CompareAndSwapUint64(&g.valBits, oldBits, newBits) {
+			return
+		}
+	}
+}
+
+func (g *gauge) Sub(val float64) {
+	g.Add(val * -1)
+}
+
+func (g *gauge) Write(out *dto.Metric) error {
+	val := math.Float64frombits(atomic.LoadUint64(&g.valBits))
+	return populateMetric(GaugeValue, val, g.labelPairs, out)
+}
+
+// GaugeVec is a Collector that bundles a set of Gauges that all share the same
+// Desc, but have different values for their variable labels. This is used if
+// you want to count the same thing partitioned by various dimensions
+// (e.g. number of operations queued, partitioned by user and operation
+// type). Create instances with NewGaugeVec.
+type GaugeVec struct {
+	*metricVec
+}
+
+// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and
+// partitioned by the given label names.
+func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &GaugeVec{
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			if len(lvs) != len(desc.variableLabels) {
+				panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, lvs))
+			}
+			result := &gauge{desc: desc, labelPairs: makeLabelPairs(desc, lvs)}
+			result.init(result) // Init self-collection.
+			return result
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Gauge for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Gauge is created.
+//
+// It is possible to call this method without using the returned Gauge to only
+// create the new Gauge but leave it at its starting value 0. See also the
+// SummaryVec example.
+//
+// Keeping the Gauge for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Gauge from the GaugeVec. In that case, the
+// Gauge will still exist, but it will not be exported anymore, even if a
+// Gauge with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Gauge for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Gauge is created. Implications of
+// creating a Gauge without using it and keeping the Gauge for later use are
+// the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
+	if metric != nil {
+		return metric.(Gauge), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Add(42)
+func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
+	g, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// With works as GetMetricWith, but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
+func (v *GaugeVec) With(labels Labels) Gauge {
+	g, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return g
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the GaugeVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &GaugeVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+// GaugeFunc is a Gauge whose value is determined at collect time by calling a
+// provided function.
+//
+// To create GaugeFunc instances, use NewGaugeFunc.
+type GaugeFunc interface {
+	Metric
+	Collector
+}
+
+// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
+// value reported is determined by calling the given function from within the
+// Write method. Take into account that metric collection may happen
+// concurrently. If that results in concurrent calls to Write, like in the case
+// where a GaugeFunc is directly registered with Prometheus, the provided
+// function must be concurrency-safe.
+func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
+	return newValueFunc(NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		nil,
+		opts.ConstLabels,
+	), GaugeValue, function)
+}

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -0,0 +1,301 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"runtime"
+	"runtime/debug"
+	"time"
+)
+
+type goCollector struct {
+	goroutinesDesc *Desc
+	threadsDesc    *Desc
+	gcDesc         *Desc
+	goInfoDesc     *Desc
+
+	// metrics to describe and collect
+	metrics memStatsMetrics
+}
+
+// NewGoCollector returns a collector which exports metrics about the current Go
+// process. This includes memory stats. To collect those, runtime.ReadMemStats
+// is called. This causes a stop-the-world, which is very short with Go1.9+
+// (~25µs). However, with older Go versions, the stop-the-world duration depends
+// on the heap size and can be quite significant (~1.7 ms/GiB as per
+// https://go-review.googlesource.com/c/go/+/34937).
+func NewGoCollector() Collector {
+	return &goCollector{
+		goroutinesDesc: NewDesc(
+			"go_goroutines",
+			"Number of goroutines that currently exist.",
+			nil, nil),
+		threadsDesc: NewDesc(
+			"go_threads",
+			"Number of OS threads created.",
+			nil, nil),
+		gcDesc: NewDesc(
+			"go_gc_duration_seconds",
+			"A summary of the GC invocation durations.",
+			nil, nil),
+		goInfoDesc: NewDesc(
+			"go_info",
+			"Information about the Go environment.",
+			nil, Labels{"version": runtime.Version()}),
+		metrics: memStatsMetrics{
+			{
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes"),
+					"Number of bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("alloc_bytes_total"),
+					"Total number of bytes allocated, even if freed.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("sys_bytes"),
+					"Number of bytes obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("lookups_total"),
+					"Total number of pointer lookups.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mallocs_total"),
+					"Total number of mallocs.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("frees_total"),
+					"Total number of frees.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
+				valType: CounterValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_alloc_bytes"),
+					"Number of heap bytes allocated and still in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_sys_bytes"),
+					"Number of heap bytes obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_idle_bytes"),
+					"Number of heap bytes waiting to be used.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_inuse_bytes"),
+					"Number of heap bytes that are in use.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_released_bytes"),
+					"Number of heap bytes released to OS.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("heap_objects"),
+					"Number of allocated objects.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_inuse_bytes"),
+					"Number of bytes in use by the stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("stack_sys_bytes"),
+					"Number of bytes obtained from system for stack allocator.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_inuse_bytes"),
+					"Number of bytes in use by mspan structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mspan_sys_bytes"),
+					"Number of bytes used for mspan structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_inuse_bytes"),
+					"Number of bytes in use by mcache structures.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("mcache_sys_bytes"),
+					"Number of bytes used for mcache structures obtained from system.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("buck_hash_sys_bytes"),
+					"Number of bytes used by the profiling bucket hash table.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_sys_bytes"),
+					"Number of bytes used for garbage collection system metadata.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("other_sys_bytes"),
+					"Number of bytes used for other system allocations.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("next_gc_bytes"),
+					"Number of heap bytes when next garbage collection will take place.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("last_gc_time_seconds"),
+					"Number of seconds since 1970 of last garbage collection.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 },
+				valType: GaugeValue,
+			}, {
+				desc: NewDesc(
+					memstatNamespace("gc_cpu_fraction"),
+					"The fraction of this program's available CPU time used by the GC since the program started.",
+					nil, nil,
+				),
+				eval:    func(ms *runtime.MemStats) float64 { return ms.GCCPUFraction },
+				valType: GaugeValue,
+			},
+		},
+	}
+}
+
+func memstatNamespace(s string) string {
+	return fmt.Sprintf("go_memstats_%s", s)
+}
+
+// Describe returns all descriptions of the collector.
+func (c *goCollector) Describe(ch chan<- *Desc) {
+	ch <- c.goroutinesDesc
+	ch <- c.threadsDesc
+	ch <- c.gcDesc
+	ch <- c.goInfoDesc
+	for _, i := range c.metrics {
+		ch <- i.desc
+	}
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *goCollector) Collect(ch chan<- Metric) {
+	ch <- MustNewConstMetric(c.goroutinesDesc, GaugeValue, float64(runtime.NumGoroutine()))
+	n, _ := runtime.ThreadCreateProfile(nil)
+	ch <- MustNewConstMetric(c.threadsDesc, GaugeValue, float64(n))
+
+	var stats debug.GCStats
+	stats.PauseQuantiles = make([]time.Duration, 5)
+	debug.ReadGCStats(&stats)
+
+	quantiles := make(map[float64]float64)
+	for idx, pq := range stats.PauseQuantiles[1:] {
+		quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds()
+	}
+	quantiles[0.0] = stats.PauseQuantiles[0].Seconds()
+	ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), stats.PauseTotal.Seconds(), quantiles)
+
+	ch <- MustNewConstMetric(c.goInfoDesc, GaugeValue, 1)
+
+	ms := &runtime.MemStats{}
+	runtime.ReadMemStats(ms)
+	for _, i := range c.metrics {
+		ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms))
+	}
+}
+
+// memStatsMetrics provide description, value, and value type for memstat metrics.
+type memStatsMetrics []struct {
+	desc    *Desc
+	eval    func(*runtime.MemStats) float64
+	valType ValueType
+}

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -0,0 +1,614 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"fmt"
+	"math"
+	"runtime"
+	"sort"
+	"sync"
+	"sync/atomic"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// A Histogram counts individual observations from an event or sample stream in
+// configurable buckets. Similar to a summary, it also provides a sum of
+// observations and an observation count.
+//
+// On the Prometheus server, quantiles can be calculated from a Histogram using
+// the histogram_quantile function in the query language.
+//
+// Note that Histograms, in contrast to Summaries, can be aggregated with the
+// Prometheus query language (see the documentation for detailed
+// procedures). However, Histograms require the user to pre-define suitable
+// buckets, and they are in general less accurate. The Observe method of a
+// Histogram has a very low performance overhead in comparison with the Observe
+// method of a Summary.
+//
+// To create Histogram instances, use NewHistogram.
+type Histogram interface {
+	Metric
+	Collector
+
+	// Observe adds a single observation to the histogram.
+	Observe(float64)
+}
+
+// bucketLabel is used for the label that defines the upper bound of a
+// bucket of a histogram ("le" -> "less or equal").
+const bucketLabel = "le"
+
+// DefBuckets are the default Histogram buckets. The default buckets are
+// tailored to broadly measure the response time (in seconds) of a network
+// service. Most likely, however, you will be required to define buckets
+// customized to your use case.
+var (
+	DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10}
+
+	errBucketLabelNotAllowed = fmt.Errorf(
+		"%q is not allowed as label name in histograms", bucketLabel,
+	)
+)
+
+// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest
+// bucket has an upper bound of 'start'. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is zero or negative.
+func LinearBuckets(start, width float64, count int) []float64 {
+	if count < 1 {
+		panic("LinearBuckets needs a positive count")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start += width
+	}
+	return buckets
+}
+
+// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an
+// upper bound of 'start' and each following bucket's upper bound is 'factor'
+// times the previous bucket's upper bound. The final +Inf bucket is not counted
+// and not included in the returned slice. The returned slice is meant to be
+// used for the Buckets field of HistogramOpts.
+//
+// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative,
+// or if 'factor' is less than or equal 1.
+func ExponentialBuckets(start, factor float64, count int) []float64 {
+	if count < 1 {
+		panic("ExponentialBuckets needs a positive count")
+	}
+	if start <= 0 {
+		panic("ExponentialBuckets needs a positive start value")
+	}
+	if factor <= 1 {
+		panic("ExponentialBuckets needs a factor greater than 1")
+	}
+	buckets := make([]float64, count)
+	for i := range buckets {
+		buckets[i] = start
+		start *= factor
+	}
+	return buckets
+}
+
+// HistogramOpts bundles the options for creating a Histogram metric. It is
+// mandatory to set Name to a non-empty string. All other fields are optional
+// and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type HistogramOpts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Histogram (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the Histogram must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this Histogram.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
+	ConstLabels Labels
+
+	// Buckets defines the buckets into which observations are counted. Each
+	// element in the slice is the upper inclusive bound of a bucket. The
+	// values must be sorted in strictly increasing order. There is no need
+	// to add a highest bucket with +Inf bound, it will be added
+	// implicitly. The default value is DefBuckets.
+	Buckets []float64
+}
+
+// NewHistogram creates a new Histogram based on the provided HistogramOpts. It
+// panics if the buckets in HistogramOpts are not in strictly increasing order.
+func NewHistogram(opts HistogramOpts) Histogram {
+	return newHistogram(
+		NewDesc(
+			BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+			opts.Help,
+			nil,
+			opts.ConstLabels,
+		),
+		opts,
+	)
+}
+
+func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram {
+	if len(desc.variableLabels) != len(labelValues) {
+		panic(makeInconsistentCardinalityError(desc.fqName, desc.variableLabels, labelValues))
+	}
+
+	for _, n := range desc.variableLabels {
+		if n == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+	for _, lp := range desc.constLabelPairs {
+		if lp.GetName() == bucketLabel {
+			panic(errBucketLabelNotAllowed)
+		}
+	}
+
+	if len(opts.Buckets) == 0 {
+		opts.Buckets = DefBuckets
+	}
+
+	h := &histogram{
+		desc:        desc,
+		upperBounds: opts.Buckets,
+		labelPairs:  makeLabelPairs(desc, labelValues),
+		counts:      [2]*histogramCounts{&histogramCounts{}, &histogramCounts{}},
+	}
+	for i, upperBound := range h.upperBounds {
+		if i < len(h.upperBounds)-1 {
+			if upperBound >= h.upperBounds[i+1] {
+				panic(fmt.Errorf(
+					"histogram buckets must be in increasing order: %f >= %f",
+					upperBound, h.upperBounds[i+1],
+				))
+			}
+		} else {
+			if math.IsInf(upperBound, +1) {
+				// The +Inf bucket is implicit. Remove it here.
+				h.upperBounds = h.upperBounds[:i]
+			}
+		}
+	}
+	// Finally we know the final length of h.upperBounds and can make counts
+	// for both states:
+	h.counts[0].buckets = make([]uint64, len(h.upperBounds))
+	h.counts[1].buckets = make([]uint64, len(h.upperBounds))
+
+	h.init(h) // Init self-collection.
+	return h
+}
+
+type histogramCounts struct {
+	// sumBits contains the bits of the float64 representing the sum of all
+	// observations. sumBits and count have to go first in the struct to
+	// guarantee alignment for atomic operations.
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	sumBits uint64
+	count   uint64
+	buckets []uint64
+}
+
+type histogram struct {
+	// countAndHotIdx is a complicated one. For lock-free yet atomic
+	// observations, we need to save the total count of observations again,
+	// combined with the index of the currently-hot counts struct, so that
+	// we can perform the operation on both values atomically. The least
+	// significant bit defines the hot counts struct. The remaining 63 bits
+	// represent the total count of observations. This happens under the
+	// assumption that the 63bit count will never overflow. Rationale: An
+	// observations takes about 30ns. Let's assume it could happen in
+	// 10ns. Overflowing the counter will then take at least (2^63)*10ns,
+	// which is about 3000 years.
+	//
+	// This has to be first in the struct for 64bit alignment. See
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG
+	countAndHotIdx uint64
+
+	selfCollector
+	desc     *Desc
+	writeMtx sync.Mutex // Only used in the Write method.
+
+	upperBounds []float64
+
+	// Two counts, one is "hot" for lock-free observations, the other is
+	// "cold" for writing out a dto.Metric. It has to be an array of
+	// pointers to guarantee 64bit alignment of the histogramCounts, see
+	// http://golang.org/pkg/sync/atomic/#pkg-note-BUG.
+	counts [2]*histogramCounts
+	hotIdx int // Index of currently-hot counts. Only used within Write.
+
+	labelPairs []*dto.LabelPair
+}
+
+func (h *histogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *histogram) Observe(v float64) {
+	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
+	// slightly faster than the binary search. If we really care, we could
+	// switch from one search strategy to the other depending on the number
+	// of buckets.
+	//
+	// Microbenchmarks (BenchmarkHistogramNoLabels):
+	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
+	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
+	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	i := sort.SearchFloat64s(h.upperBounds, v)
+
+	// We increment h.countAndHotIdx by 2 so that the counter in the upper
+	// 63 bits gets incremented by 1. At the same time, we get the new value
+	// back, which we can use to find the currently-hot counts.
+	n := atomic.AddUint64(&h.countAndHotIdx, 2)
+	hotCounts := h.counts[n%2]
+
+	if i < len(h.upperBounds) {
+		atomic.AddUint64(&hotCounts.buckets[i], 1)
+	}
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + v)
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			break
+		}
+	}
+	// Increment count last as we take it as a signal that the observation
+	// is complete.
+	atomic.AddUint64(&hotCounts.count, 1)
+}
+
+func (h *histogram) Write(out *dto.Metric) error {
+	var (
+		his                   = &dto.Histogram{}
+		buckets               = make([]*dto.Bucket, len(h.upperBounds))
+		hotCounts, coldCounts *histogramCounts
+		count                 uint64
+	)
+
+	// For simplicity, we mutex the rest of this method. It is not in the
+	// hot path, i.e.  Observe is called much more often than Write. The
+	// complication of making Write lock-free isn't worth it.
+	h.writeMtx.Lock()
+	defer h.writeMtx.Unlock()
+
+	// This is a bit arcane, which is why the following spells out this if
+	// clause in English:
+	//
+	// If the currently-hot counts struct is #0, we atomically increment
+	// h.countAndHotIdx by 1 so that from now on Observe will use the counts
+	// struct #1. Furthermore, the atomic increment gives us the new value,
+	// which, in its most significant 63 bits, tells us the count of
+	// observations done so far up to and including currently ongoing
+	// observations still using the counts struct just changed from hot to
+	// cold. To have a normal uint64 for the count, we bitshift by 1 and
+	// save the result in count. We also set h.hotIdx to 1 for the next
+	// Write call, and we will refer to counts #1 as hotCounts and to counts
+	// #0 as coldCounts.
+	//
+	// If the currently-hot counts struct is #1, we do the corresponding
+	// things the other way round. We have to _decrement_ h.countAndHotIdx
+	// (which is a bit arcane in itself, as we have to express -1 with an
+	// unsigned int...).
+	if h.hotIdx == 0 {
+		count = atomic.AddUint64(&h.countAndHotIdx, 1) >> 1
+		h.hotIdx = 1
+		hotCounts = h.counts[1]
+		coldCounts = h.counts[0]
+	} else {
+		count = atomic.AddUint64(&h.countAndHotIdx, ^uint64(0)) >> 1 // Decrement.
+		h.hotIdx = 0
+		hotCounts = h.counts[0]
+		coldCounts = h.counts[1]
+	}
+
+	// Now we have to wait for the now-declared-cold counts to actually cool
+	// down, i.e. wait for all observations still using it to finish. That's
+	// the case once the count in the cold counts struct is the same as the
+	// one atomically retrieved from the upper 63bits of h.countAndHotIdx.
+	for {
+		if count == atomic.LoadUint64(&coldCounts.count) {
+			break
+		}
+		runtime.Gosched() // Let observations get work done.
+	}
+
+	his.SampleCount = proto.Uint64(count)
+	his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&coldCounts.sumBits)))
+	var cumCount uint64
+	for i, upperBound := range h.upperBounds {
+		cumCount += atomic.LoadUint64(&coldCounts.buckets[i])
+		buckets[i] = &dto.Bucket{
+			CumulativeCount: proto.Uint64(cumCount),
+			UpperBound:      proto.Float64(upperBound),
+		}
+	}
+
+	his.Bucket = buckets
+	out.Histogram = his
+	out.Label = h.labelPairs
+
+	// Finally add all the cold counts to the new hot counts and reset the cold counts.
+	atomic.AddUint64(&hotCounts.count, count)
+	atomic.StoreUint64(&coldCounts.count, 0)
+	for {
+		oldBits := atomic.LoadUint64(&hotCounts.sumBits)
+		newBits := math.Float64bits(math.Float64frombits(oldBits) + his.GetSampleSum())
+		if atomic.CompareAndSwapUint64(&hotCounts.sumBits, oldBits, newBits) {
+			atomic.StoreUint64(&coldCounts.sumBits, 0)
+			break
+		}
+	}
+	for i := range h.upperBounds {
+		atomic.AddUint64(&hotCounts.buckets[i], atomic.LoadUint64(&coldCounts.buckets[i]))
+		atomic.StoreUint64(&coldCounts.buckets[i], 0)
+	}
+	return nil
+}
+
+// HistogramVec is a Collector that bundles a set of Histograms that all share the
+// same Desc, but have different values for their variable labels. This is used
+// if you want to count the same thing partitioned by various dimensions
+// (e.g. HTTP request latencies, partitioned by status code and method). Create
+// instances with NewHistogramVec.
+type HistogramVec struct {
+	*metricVec
+}
+
+// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and
+// partitioned by the given label names.
+func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec {
+	desc := NewDesc(
+		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
+		opts.Help,
+		labelNames,
+		opts.ConstLabels,
+	)
+	return &HistogramVec{
+		metricVec: newMetricVec(desc, func(lvs ...string) Metric {
+			return newHistogram(desc, opts, lvs...)
+		}),
+	}
+}
+
+// GetMetricWithLabelValues returns the Histogram for the given slice of label
+// values (same order as the VariableLabels in Desc). If that combination of
+// label values is accessed for the first time, a new Histogram is created.
+//
+// It is possible to call this method without using the returned Histogram to only
+// create the new Histogram but leave it at its starting value, a Histogram without
+// any observations.
+//
+// Keeping the Histogram for later use is possible (and should be considered if
+// performance is critical), but keep in mind that Reset, DeleteLabelValues and
+// Delete can be used to delete the Histogram from the HistogramVec. In that case, the
+// Histogram will still exist, but it will not be exported anymore, even if a
+// Histogram with the same label values is created later. See also the CounterVec
+// example.
+//
+// An error is returned if the number of label values is not the same as the
+// number of VariableLabels in Desc (minus any curried labels).
+//
+// Note that for more than one label value, this method is prone to mistakes
+// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as
+// an alternative to avoid that type of mistake. For higher label numbers, the
+// latter has a much more readable (albeit more verbose) syntax, but it comes
+// with a performance overhead (for creating and processing the Labels map).
+// See also the GaugeVec example.
+func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
+	metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// GetMetricWith returns the Histogram for the given Labels map (the label names
+// must match those of the VariableLabels in Desc). If that label map is
+// accessed for the first time, a new Histogram is created. Implications of
+// creating a Histogram without using it and keeping the Histogram for later use
+// are the same as for GetMetricWithLabelValues.
+//
+// An error is returned if the number and names of the Labels are inconsistent
+// with those of the VariableLabels in Desc (minus any curried labels).
+//
+// This method is used for the same purpose as
+// GetMetricWithLabelValues(...string). See there for pros and cons of the two
+// methods.
+func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) {
+	metric, err := v.metricVec.getMetricWith(labels)
+	if metric != nil {
+		return metric.(Observer), err
+	}
+	return nil, err
+}
+
+// WithLabelValues works as GetMetricWithLabelValues, but panics where
+// GetMetricWithLabelValues would have returned an error. Not returning an
+// error allows shortcuts like
+//     myVec.WithLabelValues("404", "GET").Observe(42.21)
+func (v *HistogramVec) WithLabelValues(lvs ...string) Observer {
+	h, err := v.GetMetricWithLabelValues(lvs...)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// With works as GetMetricWith but panics where GetMetricWithLabels would have
+// returned an error. Not returning an error allows shortcuts like
+//     myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
+func (v *HistogramVec) With(labels Labels) Observer {
+	h, err := v.GetMetricWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return h
+}
+
+// CurryWith returns a vector curried with the provided labels, i.e. the
+// returned vector has those labels pre-set for all labeled operations performed
+// on it. The cardinality of the curried vector is reduced accordingly. The
+// order of the remaining labels stays the same (just with the curried labels
+// taken out of the sequence – which is relevant for the
+// (GetMetric)WithLabelValues methods). It is possible to curry a curried
+// vector, but only with labels not yet used for currying before.
+//
+// The metrics contained in the HistogramVec are shared between the curried and
+// uncurried vectors. They are just accessed differently. Curried and uncurried
+// vectors behave identically in terms of collection. Only one must be
+// registered with a given registry (usually the uncurried version). The Reset
+// method deletes all metrics, even if called on a curried vector.
+func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) {
+	vec, err := v.curryWith(labels)
+	if vec != nil {
+		return &HistogramVec{vec}, err
+	}
+	return nil, err
+}
+
+// MustCurryWith works as CurryWith but panics where CurryWith would have
+// returned an error.
+func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec {
+	vec, err := v.CurryWith(labels)
+	if err != nil {
+		panic(err)
+	}
+	return vec
+}
+
+type constHistogram struct {
+	desc       *Desc
+	count      uint64
+	sum        float64
+	buckets    map[float64]uint64
+	labelPairs []*dto.LabelPair
+}
+
+func (h *constHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *constHistogram) Write(out *dto.Metric) error {
+	his := &dto.Histogram{}
+	buckets := make([]*dto.Bucket, 0, len(h.buckets))
+
+	his.SampleCount = proto.Uint64(h.count)
+	his.SampleSum = proto.Float64(h.sum)
+
+	for upperBound, count := range h.buckets {
+		buckets = append(buckets, &dto.Bucket{
+			CumulativeCount: proto.Uint64(count),
+			UpperBound:      proto.Float64(upperBound),
+		})
+	}
+
+	if len(buckets) > 0 {
+		sort.Sort(buckSort(buckets))
+	}
+	his.Bucket = buckets
+
+	out.Histogram = his
+	out.Label = h.labelPairs
+
+	return nil
+}
+
+// NewConstHistogram returns a metric representing a Prometheus histogram with
+// fixed values for the count, sum, and bucket counts. As those parameters
+// cannot be changed, the returned value does not implement the Histogram
+// interface (but only the Metric interface). Users of this package will not
+// have much use for it in regular operations. However, when implementing custom
+// Collectors, it is useful as a throw-away metric that is generated on the fly
+// to send it to Prometheus in the Collect method.
+//
+// buckets is a map of upper bounds to cumulative counts, excluding the +Inf
+// bucket.
+//
+// NewConstHistogram returns an error if the length of labelValues is not
+// consistent with the variable labels in Desc or if Desc is invalid.
+func NewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil {
+		return nil, err
+	}
+	return &constHistogram{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		buckets:    buckets,
+		labelPairs: makeLabelPairs(desc, labelValues),
+	}, nil
+}
+
+// MustNewConstHistogram is a version of NewConstHistogram that panics where
+// NewConstMetric would have returned an error.
+func MustNewConstHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
+type buckSort []*dto.Bucket
+
+func (s buckSort) Len() int {
+	return len(s)
+}
+
+func (s buckSort) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s buckSort) Less(i, j int) bool {
+	return s[i].GetUpperBound() < s[j].GetUpperBound()
+}

vendor/github.com/prometheus/client_golang/prometheus/http.go

@@ -0,0 +1,504 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"bufio"
+	"compress/gzip"
+	"io"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/prometheus/common/expfmt"
+)
+
+// TODO(beorn7): Remove this whole file. It is a partial mirror of
+// promhttp/http.go (to avoid circular import chains) where everything HTTP
+// related should live. The functions here are just for avoiding
+// breakage. Everything is deprecated.
+
+const (
+	contentTypeHeader     = "Content-Type"
+	contentLengthHeader   = "Content-Length"
+	contentEncodingHeader = "Content-Encoding"
+	acceptEncodingHeader  = "Accept-Encoding"
+)
+
+var gzipPool = sync.Pool{
+	New: func() interface{} {
+		return gzip.NewWriter(nil)
+	},
+}
+
+// Handler returns an HTTP handler for the DefaultGatherer. It is
+// already instrumented with InstrumentHandler (using "prometheus" as handler
+// name).
+//
+// Deprecated: Please note the issues described in the doc comment of
+// InstrumentHandler. You might want to consider using promhttp.Handler instead.
+func Handler() http.Handler {
+	return InstrumentHandler("prometheus", UninstrumentedHandler())
+}
+
+// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer.
+//
+// Deprecated: Use promhttp.HandlerFor(DefaultGatherer, promhttp.HandlerOpts{})
+// instead. See there for further documentation.
+func UninstrumentedHandler() http.Handler {
+	return http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
+		mfs, err := DefaultGatherer.Gather()
+		if err != nil {
+			httpError(rsp, err)
+			return
+		}
+
+		contentType := expfmt.Negotiate(req.Header)
+		header := rsp.Header()
+		header.Set(contentTypeHeader, string(contentType))
+
+		w := io.Writer(rsp)
+		if gzipAccepted(req.Header) {
+			header.Set(contentEncodingHeader, "gzip")
+			gz := gzipPool.Get().(*gzip.Writer)
+			defer gzipPool.Put(gz)
+
+			gz.Reset(w)
+			defer gz.Close()
+
+			w = gz
+		}
+
+		enc := expfmt.NewEncoder(w, contentType)
+
+		for _, mf := range mfs {
+			if err := enc.Encode(mf); err != nil {
+				httpError(rsp, err)
+				return
+			}
+		}
+	})
+}
+
+var instLabels = []string{"method", "code"}
+
+type nower interface {
+	Now() time.Time
+}
+
+type nowFunc func() time.Time
+
+func (n nowFunc) Now() time.Time {
+	return n()
+}
+
+var now nower = nowFunc(func() time.Time {
+	return time.Now()
+})
+
+// InstrumentHandler wraps the given HTTP handler for instrumentation. It
+// registers four metric collectors (if not already done) and reports HTTP
+// metrics to the (newly or already) registered collectors: http_requests_total
+// (CounterVec), http_request_duration_microseconds (Summary),
+// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each
+// has a constant label named "handler" with the provided handlerName as
+// value. http_requests_total is a metric vector partitioned by HTTP method
+// (label name "method") and HTTP status code (label name "code").
+//
+// Deprecated: InstrumentHandler has several issues. Use the tooling provided in
+// package promhttp instead. The issues are the following: (1) It uses Summaries
+// rather than Histograms. Summaries are not useful if aggregation across
+// multiple instances is required. (2) It uses microseconds as unit, which is
+// deprecated and should be replaced by seconds. (3) The size of the request is
+// calculated in a separate goroutine. Since this calculator requires access to
+// the request header, it creates a race with any writes to the header performed
+// during request handling.  httputil.ReverseProxy is a prominent example for a
+// handler performing such writes. (4) It has additional issues with HTTP/2, cf.
+// https://github.com/prometheus/client_golang/issues/272.
+func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc {
+	return InstrumentHandlerFunc(handlerName, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFunc wraps the given function for instrumentation. It
+// otherwise works in the same way as InstrumentHandler (and shares the same
+// issues).
+//
+// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+	return InstrumentHandlerFuncWithOpts(
+		SummaryOpts{
+			Subsystem:   "http",
+			ConstLabels: Labels{"handler": handlerName},
+			Objectives:  map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
+		},
+		handlerFunc,
+	)
+}
+
+// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same
+// issues) but provides more flexibility (at the cost of a more complex call
+// syntax). As InstrumentHandler, this function registers four metric
+// collectors, but it uses the provided SummaryOpts to create them. However, the
+// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced
+// by "requests_total", "request_duration_microseconds", "request_size_bytes",
+// and "response_size_bytes", respectively. "Help" is replaced by an appropriate
+// help string. The names of the variable labels of the http_requests_total
+// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code).
+//
+// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the
+// behavior of InstrumentHandler:
+//
+//     prometheus.InstrumentHandlerWithOpts(
+//         prometheus.SummaryOpts{
+//              Subsystem:   "http",
+//              ConstLabels: prometheus.Labels{"handler": handlerName},
+//         },
+//         handler,
+//     )
+//
+// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it
+// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally,
+// and all its fields are set to the equally named fields in the provided
+// SummaryOpts.
+//
+// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as
+// InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc {
+	return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP)
+}
+
+// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares
+// the same issues) but provides more flexibility (at the cost of a more complex
+// call syntax). See InstrumentHandlerWithOpts for details how the provided
+// SummaryOpts are used.
+//
+// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons
+// as InstrumentHandler is. Use the tooling provided in package promhttp instead.
+func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc {
+	reqCnt := NewCounterVec(
+		CounterOpts{
+			Namespace:   opts.Namespace,
+			Subsystem:   opts.Subsystem,
+			Name:        "requests_total",
+			Help:        "Total number of HTTP requests made.",
+			ConstLabels: opts.ConstLabels,
+		},
+		instLabels,
+	)
+	if err := Register(reqCnt); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqCnt = are.ExistingCollector.(*CounterVec)
+		} else {
+			panic(err)
+		}
+	}
+
+	opts.Name = "request_duration_microseconds"
+	opts.Help = "The HTTP request latencies in microseconds."
+	reqDur := NewSummary(opts)
+	if err := Register(reqDur); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqDur = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
+
+	opts.Name = "request_size_bytes"
+	opts.Help = "The HTTP request sizes in bytes."
+	reqSz := NewSummary(opts)
+	if err := Register(reqSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			reqSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
+
+	opts.Name = "response_size_bytes"
+	opts.Help = "The HTTP response sizes in bytes."
+	resSz := NewSummary(opts)
+	if err := Register(resSz); err != nil {
+		if are, ok := err.(AlreadyRegisteredError); ok {
+			resSz = are.ExistingCollector.(Summary)
+		} else {
+			panic(err)
+		}
+	}
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		now := time.Now()
+
+		delegate := &responseWriterDelegator{ResponseWriter: w}
+		out := computeApproximateRequestSize(r)
+
+		_, cn := w.(http.CloseNotifier)
+		_, fl := w.(http.Flusher)
+		_, hj := w.(http.Hijacker)
+		_, rf := w.(io.ReaderFrom)
+		var rw http.ResponseWriter
+		if cn && fl && hj && rf {
+			rw = &fancyResponseWriterDelegator{delegate}
+		} else {
+			rw = delegate
+		}
+		handlerFunc(rw, r)
+
+		elapsed := float64(time.Since(now)) / float64(time.Microsecond)
+
+		method := sanitizeMethod(r.Method)
+		code := sanitizeCode(delegate.status)
+		reqCnt.WithLabelValues(method, code).Inc()
+		reqDur.Observe(elapsed)
+		resSz.Observe(float64(delegate.written))
+		reqSz.Observe(float64(<-out))
+	})
+}
+
+func computeApproximateRequestSize(r *http.Request) <-chan int {
+	// Get URL length in current goroutine for avoiding a race condition.
+	// HandlerFunc that runs in parallel may modify the URL.
+	s := 0
+	if r.URL != nil {
+		s += len(r.URL.String())
+	}
+
+	out := make(chan int, 1)
+
+	go func() {
+		s += len(r.Method)
+		s += len(r.Proto)
+		for name, values := range r.Header {
+			s += len(name)
+			for _, value := range values {
+				s += len(value)
+			}
+		}
+		s += len(r.Host)
+
+		// N.B. r.Form and r.MultipartForm are assumed to be included in r.URL.
+
+		if r.ContentLength != -1 {
+			s += int(r.ContentLength)
+		}
+		out <- s
+		close(out)
+	}()
+
+	return out
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	status      int
+	written     int64
+	wroteHeader bool
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type fancyResponseWriterDelegator struct {
+	*responseWriterDelegator
+}
+
+func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool {
+	return f.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+
+func (f *fancyResponseWriterDelegator) Flush() {
+	f.ResponseWriter.(http.Flusher).Flush()
+}
+
+func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return f.ResponseWriter.(http.Hijacker).Hijack()
+}
+
+func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) {
+	if !f.wroteHeader {
+		f.WriteHeader(http.StatusOK)
+	}
+	n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r)
+	f.written += n
+	return n, err
+}
+
+func sanitizeMethod(m string) string {
+	switch m {
+	case "GET", "get":
+		return "get"
+	case "PUT", "put":
+		return "put"
+	case "HEAD", "head":
+		return "head"
+	case "POST", "post":
+		return "post"
+	case "DELETE", "delete":
+		return "delete"
+	case "CONNECT", "connect":
+		return "connect"
+	case "OPTIONS", "options":
+		return "options"
+	case "NOTIFY", "notify":
+		return "notify"
+	default:
+		return strings.ToLower(m)
+	}
+}
+
+func sanitizeCode(s int) string {
+	switch s {
+	case 100:
+		return "100"
+	case 101:
+		return "101"
+
+	case 200:
+		return "200"
+	case 201:
+		return "201"
+	case 202:
+		return "202"
+	case 203:
+		return "203"
+	case 204:
+		return "204"
+	case 205:
+		return "205"
+	case 206:
+		return "206"
+
+	case 300:
+		return "300"
+	case 301:
+		return "301"
+	case 302:
+		return "302"
+	case 304:
+		return "304"
+	case 305:
+		return "305"
+	case 307:
+		return "307"
+
+	case 400:
+		return "400"
+	case 401:
+		return "401"
+	case 402:
+		return "402"
+	case 403:
+		return "403"
+	case 404:
+		return "404"
+	case 405:
+		return "405"
+	case 406:
+		return "406"
+	case 407:
+		return "407"
+	case 408:
+		return "408"
+	case 409:
+		return "409"
+	case 410:
+		return "410"
+	case 411:
+		return "411"
+	case 412:
+		return "412"
+	case 413:
+		return "413"
+	case 414:
+		return "414"
+	case 415:
+		return "415"
+	case 416:
+		return "416"
+	case 417:
+		return "417"
+	case 418:
+		return "418"
+
+	case 500:
+		return "500"
+	case 501:
+		return "501"
+	case 502:
+		return "502"
+	case 503:
+		return "503"
+	case 504:
+		return "504"
+	case 505:
+		return "505"
+
+	case 428:
+		return "428"
+	case 429:
+		return "429"
+	case 431:
+		return "431"
+	case 511:
+		return "511"
+
+	default:
+		return strconv.Itoa(s)
+	}
+}
+
+// gzipAccepted returns whether the client will accept gzip-encoded content.
+func gzipAccepted(header http.Header) bool {
+	a := header.Get(acceptEncodingHeader)
+	parts := strings.Split(a, ",")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return true
+		}
+	}
+	return false
+}
+
+// httpError removes any content-encoding header and then calls http.Error with
+// the provided error and http.StatusInternalServerErrer. Error contents is
+// supposed to be uncompressed plain text. However, same as with a plain
+// http.Error, any header settings will be void if the header has already been
+// sent. The error message will still be written to the writer, but it will
+// probably be of limited use.
+func httpError(rsp http.ResponseWriter, err error) {
+	rsp.Header().Del(contentEncodingHeader)
+	http.Error(
+		rsp,
+		"An error has occurred while serving metrics:\n\n"+err.Error(),
+		http.StatusInternalServerError,
+	)
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/metric.go

@@ -0,0 +1,85 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"sort"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+// metricSorter is a sortable slice of *dto.Metric.
+type metricSorter []*dto.Metric
+
+func (s metricSorter) Len() int {
+	return len(s)
+}
+
+func (s metricSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s metricSorter) Less(i, j int) bool {
+	if len(s[i].Label) != len(s[j].Label) {
+		// This should not happen. The metrics are
+		// inconsistent. However, we have to deal with the fact, as
+		// people might use custom collectors or metric family injection
+		// to create inconsistent metrics. So let's simply compare the
+		// number of labels in this case. That will still yield
+		// reproducible sorting.
+		return len(s[i].Label) < len(s[j].Label)
+	}
+	for n, lp := range s[i].Label {
+		vi := lp.GetValue()
+		vj := s[j].Label[n].GetValue()
+		if vi != vj {
+			return vi < vj
+		}
+	}
+
+	// We should never arrive here. Multiple metrics with the same
+	// label set in the same scrape will lead to undefined ingestion
+	// behavior. However, as above, we have to provide stable sorting
+	// here, even for inconsistent metrics. So sort equal metrics
+	// by their timestamp, with missing timestamps (implying "now")
+	// coming last.
+	if s[i].TimestampMs == nil {
+		return false
+	}
+	if s[j].TimestampMs == nil {
+		return true
+	}
+	return s[i].GetTimestampMs() < s[j].GetTimestampMs()
+}
+
+// NormalizeMetricFamilies returns a MetricFamily slice with empty
+// MetricFamilies pruned and the remaining MetricFamilies sorted by name within
+// the slice, with the contained Metrics sorted within each MetricFamily.
+func NormalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily {
+	for _, mf := range metricFamiliesByName {
+		sort.Sort(metricSorter(mf.Metric))
+	}
+	names := make([]string, 0, len(metricFamiliesByName))
+	for name, mf := range metricFamiliesByName {
+		if len(mf.Metric) > 0 {
+			names = append(names, name)
+		}
+	}
+	sort.Strings(names)
+	result := make([]*dto.MetricFamily, 0, len(names))
+	for _, name := range names {
+		result = append(result, metricFamiliesByName[name])
+	}
+	return result
+}

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -0,0 +1,87 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/prometheus/common/model"
+)
+
+// Labels represents a collection of label name -> value mappings. This type is
+// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
+// metric vector Collectors, e.g.:
+//     myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
+//
+// The other use-case is the specification of constant label pairs in Opts or to
+// create a Desc.
+type Labels map[string]string
+
+// reservedLabelPrefix is a prefix which is not legal in user-supplied
+// label names.
+const reservedLabelPrefix = "__"
+
+var errInconsistentCardinality = errors.New("inconsistent label cardinality")
+
+func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
+	return fmt.Errorf(
+		"%s: %q has %d variable labels named %q but %d values %q were provided",
+		errInconsistentCardinality, fqName,
+		len(labels), labels,
+		len(labelValues), labelValues,
+	)
+}
+
+func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
+	if len(labels) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(labels), labels,
+		)
+	}
+
+	for name, val := range labels {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
+		}
+	}
+
+	return nil
+}
+
+func validateLabelValues(vals []string, expectedNumberOfValues int) error {
+	if len(vals) != expectedNumberOfValues {
+		return fmt.Errorf(
+			"%s: expected %d label values but got %d in %#v",
+			errInconsistentCardinality, expectedNumberOfValues,
+			len(vals), vals,
+		)
+	}
+
+	for _, val := range vals {
+		if !utf8.ValidString(val) {
+			return fmt.Errorf("label value %q is not valid UTF-8", val)
+		}
+	}
+
+	return nil
+}
+
+func checkLabelName(l string) bool {
+	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+}

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -0,0 +1,174 @@
+// Copyright 2014 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"strings"
+	"time"
+
+	"github.com/golang/protobuf/proto"
+
+	dto "github.com/prometheus/client_model/go"
+)
+
+const separatorByte byte = 255
+
+// A Metric models a single sample value with its meta data being exported to
+// Prometheus. Implementations of Metric in this package are Gauge, Counter,
+// Histogram, Summary, and Untyped.
+type Metric interface {
+	// Desc returns the descriptor for the Metric. This method idempotently
+	// returns the same descriptor throughout the lifetime of the
+	// Metric. The returned descriptor is immutable by contract. A Metric
+	// unable to describe itself must return an invalid descriptor (created
+	// with NewInvalidDesc).
+	Desc() *Desc
+	// Write encodes the Metric into a "Metric" Protocol Buffer data
+	// transmission object.
+	//
+	// Metric implementations must observe concurrency safety as reads of
+	// this metric may occur at any time, and any blocking occurs at the
+	// expense of total performance of rendering all registered
+	// metrics. Ideally, Metric implementations should support concurrent
+	// readers.
+	//
+	// While populating dto.Metric, it is the responsibility of the
+	// implementation to ensure validity of the Metric protobuf (like valid
+	// UTF-8 strings or syntactically valid metric and label names). It is
+	// recommended to sort labels lexicographically. Callers of Write should
+	// still make sure of sorting if they depend on it.
+	Write(*dto.Metric) error
+	// TODO(beorn7): The original rationale of passing in a pre-allocated
+	// dto.Metric protobuf to save allocations has disappeared. The
+	// signature of this method should be changed to "Write() (*dto.Metric,
+	// error)".
+}
+
+// Opts bundles the options for creating most Metric types. Each metric
+// implementation XXX has its own XXXOpts type, but in most cases, it is just be
+// an alias of this type (which might change when the requirement arises.)
+//
+// It is mandatory to set Name to a non-empty string. All other fields are
+// optional and can safely be left at their zero value, although it is strongly
+// encouraged to set a Help string.
+type Opts struct {
+	// Namespace, Subsystem, and Name are components of the fully-qualified
+	// name of the Metric (created by joining these components with
+	// "_"). Only Name is mandatory, the others merely help structuring the
+	// name. Note that the fully-qualified name of the metric must be a
+	// valid Prometheus metric name.
+	Namespace string
+	Subsystem string
+	Name      string
+
+	// Help provides information about this metric.
+	//
+	// Metrics with the same fully-qualified name must have the same Help
+	// string.
+	Help string
+
+	// ConstLabels are used to attach fixed labels to this metric. Metrics
+	// with the same fully-qualified name must have the same label names in
+	// their ConstLabels.
+	//
+	// ConstLabels are only used rarely. In particular, do not use them to
+	// attach the same labels to all your metrics. Those use cases are
+	// better covered by target labels set by the scraping Prometheus
+	// server, or by one specific metric (e.g. a build_info or a
+	// machine_role metric). See also
+	// https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels
+	ConstLabels Labels
+}
+
+// BuildFQName joins the given three name components by "_". Empty name
+// components are ignored. If the name parameter itself is empty, an empty
+// string is returned, no matter what. Metric implementations included in this
+// library use this function internally to generate the fully-qualified metric
+// name from the name component in their Opts. Users of the library will only
+// need this function if they implement their own Metric or instantiate a Desc
+// (with NewDesc) directly.
+func BuildFQName(namespace, subsystem, name string) string {
+	if name == "" {
+		return ""
+	}
+	switch {
+	case namespace != "" && subsystem != "":
+		return strings.Join([]string{namespace, subsystem, name}, "_")
+	case namespace != "":
+		return strings.Join([]string{namespace, name}, "_")
+	case subsystem != "":
+		return strings.Join([]string{subsystem, name}, "_")
+	}
+	return name
+}
+
+// labelPairSorter implements sort.Interface. It is used to sort a slice of
+// dto.LabelPair pointers.
+type labelPairSorter []*dto.LabelPair
+
+func (s labelPairSorter) Len() int {
+	return len(s)
+}
+
+func (s labelPairSorter) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s labelPairSorter) Less(i, j int) bool {
+	return s[i].GetName() < s[j].GetName()
+}
+
+type invalidMetric struct {
+	desc *Desc
+	err  error
+}
+
+// NewInvalidMetric returns a metric whose Write method always returns the
+// provided error. It is useful if a Collector finds itself unable to collect
+// a metric and wishes to report an error to the registry.
+func NewInvalidMetric(desc *Desc, err error) Metric {
+	return &invalidMetric{desc, err}
+}
+
+func (m *invalidMetric) Desc() *Desc { return m.desc }
+
+func (m *invalidMetric) Write(*dto.Metric) error { return m.err }
+
+type timestampedMetric struct {
+	Metric
+	t time.Time
+}
+
+func (m timestampedMetric) Write(pb *dto.Metric) error {
+	e := m.Metric.Write(pb)
+	pb.TimestampMs = proto.Int64(m.t.Unix()*1000 + int64(m.t.Nanosecond()/1000000))
+	return e
+}
+
+// NewMetricWithTimestamp returns a new Metric wrapping the provided Metric in a
+// way that it has an explicit timestamp set to the provided Time. This is only
+// useful in rare cases as the timestamp of a Prometheus metric should usually
+// be set by the Prometheus server during scraping. Exceptions include mirroring
+// metrics with given timestamps from other metric
+// sources.
+//
+// NewMetricWithTimestamp works best with MustNewConstMetric,
+// MustNewConstHistogram, and MustNewConstSummary, see example.
+//
+// Currently, the exposition formats used by Prometheus are limited to
+// millisecond resolution. Thus, the provided time will be rounded down to the
+// next full millisecond value.
+func NewMetricWithTimestamp(t time.Time, m Metric) Metric {
+	return timestampedMetric{Metric: m, t: t}
+}

vendor/github.com/prometheus/client_golang/prometheus/observer.go

@@ -0,0 +1,52 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+// Observer is the interface that wraps the Observe method, which is used by
+// Histogram and Summary to add observations.
+type Observer interface {
+	Observe(float64)
+}
+
+// The ObserverFunc type is an adapter to allow the use of ordinary
+// functions as Observers. If f is a function with the appropriate
+// signature, ObserverFunc(f) is an Observer that calls f.
+//
+// This adapter is usually used in connection with the Timer type, and there are
+// two general use cases:
+//
+// The most common one is to use a Gauge as the Observer for a Timer.
+// See the "Gauge" Timer example.
+//
+// The more advanced use case is to create a function that dynamically decides
+// which Observer to use for observing the duration. See the "Complex" Timer
+// example.
+type ObserverFunc func(float64)
+
+// Observe calls f(value). It implements Observer.
+func (f ObserverFunc) Observe(value float64) {
+	f(value)
+}
+
+// ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`.
+type ObserverVec interface {
+	GetMetricWith(Labels) (Observer, error)
+	GetMetricWithLabelValues(lvs ...string) (Observer, error)
+	With(Labels) Observer
+	WithLabelValues(...string) Observer
+	CurryWith(Labels) (ObserverVec, error)
+	MustCurryWith(Labels) ObserverVec
+
+	Collector
+}

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -0,0 +1,204 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prometheus
+
+import (
+	"errors"
+	"os"
+
+	"github.com/prometheus/procfs"
+)
+
+type processCollector struct {
+	collectFn       func(chan<- Metric)
+	pidFn           func() (int, error)
+	reportErrors    bool
+	cpuTotal        *Desc
+	openFDs, maxFDs *Desc
+	vsize, maxVsize *Desc
+	rss             *Desc
+	startTime       *Desc
+}
+
+// ProcessCollectorOpts defines the behavior of a process metrics collector
+// created with NewProcessCollector.
+type ProcessCollectorOpts struct {
+	// PidFn returns the PID of the process the collector collects metrics
+	// for. It is called upon each collection. By default, the PID of the
+	// current process is used, as determined on construction time by
+	// calling os.Getpid().
+	PidFn func() (int, error)
+	// If non-empty, each of the collected metrics is prefixed by the
+	// provided string and an underscore ("_").
+	Namespace string
+	// If true, any error encountered during collection is reported as an
+	// invalid metric (see NewInvalidMetric). Otherwise, errors are ignored
+	// and the collected metrics will be incomplete. (Possibly, no metrics
+	// will be collected at all.) While that's usually not desired, it is
+	// appropriate for the common "mix-in" of process metrics, where process
+	// metrics are nice to have, but failing to collect them should not
+	// disrupt the collection of the remaining metrics.
+	ReportErrors bool
+}
+
+// NewProcessCollector returns a collector which exports the current state of
+// process metrics including CPU, memory and file descriptor usage as well as
+// the process start time. The detailed behavior is defined by the provided
+// ProcessCollectorOpts. The zero value of ProcessCollectorOpts creates a
+// collector for the current process with an empty namespace string and no error
+// reporting.
+//
+// Currently, the collector depends on a Linux-style proc filesystem and
+// therefore only exports metrics for Linux.
+//
+// Note: An older version of this function had the following signature:
+//
+//     NewProcessCollector(pid int, namespace string) Collector
+//
+// Most commonly, it was called as
+//
+//     NewProcessCollector(os.Getpid(), "")
+//
+// The following call of the current version is equivalent to the above:
+//
+//     NewProcessCollector(ProcessCollectorOpts{})
+func NewProcessCollector(opts ProcessCollectorOpts) Collector {
+	ns := ""
+	if len(opts.Namespace) > 0 {
+		ns = opts.Namespace + "_"
+	}
+
+	c := &processCollector{
+		reportErrors: opts.ReportErrors,
+		cpuTotal: NewDesc(
+			ns+"process_cpu_seconds_total",
+			"Total user and system CPU time spent in seconds.",
+			nil, nil,
+		),
+		openFDs: NewDesc(
+			ns+"process_open_fds",
+			"Number of open file descriptors.",
+			nil, nil,
+		),
+		maxFDs: NewDesc(
+			ns+"process_max_fds",
+			"Maximum number of open file descriptors.",
+			nil, nil,
+		),
+		vsize: NewDesc(
+			ns+"process_virtual_memory_bytes",
+			"Virtual memory size in bytes.",
+			nil, nil,
+		),
+		maxVsize: NewDesc(
+			ns+"process_virtual_memory_max_bytes",
+			"Maximum amount of virtual memory available in bytes.",
+			nil, nil,
+		),
+		rss: NewDesc(
+			ns+"process_resident_memory_bytes",
+			"Resident memory size in bytes.",
+			nil, nil,
+		),
+		startTime: NewDesc(
+			ns+"process_start_time_seconds",
+			"Start time of the process since unix epoch in seconds.",
+			nil, nil,
+		),
+	}
+
+	if opts.PidFn == nil {
+		pid := os.Getpid()
+		c.pidFn = func() (int, error) { return pid, nil }
+	} else {
+		c.pidFn = opts.PidFn
+	}
+
+	// Set up process metric collection if supported by the runtime.
+	if _, err := procfs.NewStat(); err == nil {
+		c.collectFn = c.processCollect
+	} else {
+		c.collectFn = func(ch chan<- Metric) {
+			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+		}
+	}
+
+	return c
+}
+
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.maxVsize
+	ch <- c.rss
+	ch <- c.startTime
+}
+
+// Collect returns the current state of all metrics of the collector.
+func (c *processCollector) Collect(ch chan<- Metric) {
+	c.collectFn(ch)
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		c.reportError(ch, nil, err)
+		return
+	}
+
+	if stat, err := p.NewStat(); err == nil {
+		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
+		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
+		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
+		if startTime, err := stat.StartTime(); err == nil {
+			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
+		} else {
+			c.reportError(ch, c.startTime, err)
+		}
+	} else {
+		c.reportError(ch, nil, err)
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err == nil {
+		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
+	} else {
+		c.reportError(ch, c.openFDs, err)
+	}
+
+	if limits, err := p.NewLimits(); err == nil {
+		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
+		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
+	} else {
+		c.reportError(ch, nil, err)
+	}
+}
+
+func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
+	if !c.reportErrors {
+		return
+	}
+	if desc == nil {
+		desc = NewInvalidDesc(err)
+	}
+	ch <- NewInvalidMetric(desc, err)
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -0,0 +1,199 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package promhttp
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+const (
+	closeNotifier = 1 << iota
+	flusher
+	hijacker
+	readerFrom
+	pusher
+)
+
+type delegator interface {
+	http.ResponseWriter
+
+	Status() int
+	Written() int64
+}
+
+type responseWriterDelegator struct {
+	http.ResponseWriter
+
+	handler, method    string
+	status             int
+	written            int64
+	wroteHeader        bool
+	observeWriteHeader func(int)
+}
+
+func (r *responseWriterDelegator) Status() int {
+	return r.status
+}
+
+func (r *responseWriterDelegator) Written() int64 {
+	return r.written
+}
+
+func (r *responseWriterDelegator) WriteHeader(code int) {
+	r.status = code
+	r.wroteHeader = true
+	r.ResponseWriter.WriteHeader(code)
+	if r.observeWriteHeader != nil {
+		r.observeWriteHeader(code)
+	}
+}
+
+func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	if !r.wroteHeader {
+		r.WriteHeader(http.StatusOK)
+	}
+	n, err := r.ResponseWriter.Write(b)
+	r.written += int64(n)
+	return n, err
+}
+
+type closeNotifierDelegator struct{ *responseWriterDelegator }
+type flusherDelegator struct{ *responseWriterDelegator }
+type hijackerDelegator struct{ *responseWriterDelegator }
+type readerFromDelegator struct{ *responseWriterDelegator }
+
+func (d closeNotifierDelegator) CloseNotify() <-chan bool {
+	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
+}
+func (d flusherDelegator) Flush() {
+	d.ResponseWriter.(http.Flusher).Flush()
+}
+func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	return d.ResponseWriter.(http.Hijacker).Hijack()
+}
+func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
+	n, err := d.ResponseWriter.(io.ReaderFrom).ReadFrom(re)
+	d.written += n
+	return n, err
+}
+
+var pickDelegator = make([]func(*responseWriterDelegator) delegator, 32)
+
+func init() {
+	// TODO(beorn7): Code generation would help here.
+	pickDelegator[0] = func(d *responseWriterDelegator) delegator { // 0
+		return d
+	}
+	pickDelegator[closeNotifier] = func(d *responseWriterDelegator) delegator { // 1
+		return closeNotifierDelegator{d}
+	}
+	pickDelegator[flusher] = func(d *responseWriterDelegator) delegator { // 2
+		return flusherDelegator{d}
+	}
+	pickDelegator[flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 3
+		return struct {
+			*responseWriterDelegator
+			http.Flusher
+			http.CloseNotifier
+		}{d, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker] = func(d *responseWriterDelegator) delegator { // 4
+		return hijackerDelegator{d}
+	}
+	pickDelegator[hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 5
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 6
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+		}{d, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 7
+		return struct {
+			*responseWriterDelegator
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom] = func(d *responseWriterDelegator) delegator { // 8
+		return readerFromDelegator{d}
+	}
+	pickDelegator[readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 9
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 10
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+		}{d, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 11
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 12
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 13
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 14
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 15
+		return struct {
+			*responseWriterDelegator
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator_1_8.go

@@ -0,0 +1,181 @@
+// Copyright 2017 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build go1.8
+
+package promhttp
+
+import (
+	"io"
+	"net/http"
+)
+
+type pusherDelegator struct{ *responseWriterDelegator }
+
+func (d pusherDelegator) Push(target string, opts *http.PushOptions) error {
+	return d.ResponseWriter.(http.Pusher).Push(target, opts)
+}
+
+func init() {
+	pickDelegator[pusher] = func(d *responseWriterDelegator) delegator { // 16
+		return pusherDelegator{d}
+	}
+	pickDelegator[pusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 17
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+flusher] = func(d *responseWriterDelegator) delegator { // 18
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+		}{d, pusherDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 19
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker] = func(d *responseWriterDelegator) delegator { // 20
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+		}{d, pusherDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 21
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 22
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { //23
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom] = func(d *responseWriterDelegator) delegator { // 24
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+		}{d, pusherDelegator{d}, readerFromDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+closeNotifier] = func(d *responseWriterDelegator) delegator { // 25
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher] = func(d *responseWriterDelegator) delegator { // 26
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 27
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker] = func(d *responseWriterDelegator) delegator { // 28
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+closeNotifier] = func(d *responseWriterDelegator) delegator { // 29
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, closeNotifierDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher] = func(d *responseWriterDelegator) delegator { // 30
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}}
+	}
+	pickDelegator[pusher+readerFrom+hijacker+flusher+closeNotifier] = func(d *responseWriterDelegator) delegator { // 31
+		return struct {
+			*responseWriterDelegator
+			http.Pusher
+			io.ReaderFrom
+			http.Hijacker
+			http.Flusher
+			http.CloseNotifier
+		}{d, pusherDelegator{d}, readerFromDelegator{d}, hijackerDelegator{d}, flusherDelegator{d}, closeNotifierDelegator{d}}
+	}
+}
+
+func newDelegator(w http.ResponseWriter, observeWriteHeaderFunc func(int)) delegator {
+	d := &responseWriterDelegator{
+		ResponseWriter:     w,
+		observeWriteHeader: observeWriteHeaderFunc,
+	}
+
+	id := 0
+	if _, ok := w.(http.CloseNotifier); ok {
+		id += closeNotifier
+	}
+	if _, ok := w.(http.Flusher); ok {
+		id += flusher
+	}
+	if _, ok := w.(http.Hijacker); ok {
+		id += hijacker
+	}
+	if _, ok := w.(io.ReaderFrom); ok {
+		id += readerFrom
+	}
+	if _, ok := w.(http.Pusher); ok {
+		id += pusher
+	}
+
+	return pickDelegator[id](d)
+}