Files
weave-scope/render/dsl/expression.go
2015-09-01 09:25:03 +02:00

399 lines
10 KiB
Go

package dsl
import (
"fmt"
"log"
"math/rand"
"net"
"regexp"
"strings"
"github.com/weaveworks/scope/probe/endpoint"
"github.com/weaveworks/scope/probe/host"
"github.com/weaveworks/scope/render"
"github.com/weaveworks/scope/report"
)
// Evaluator describes a monadic transformer of a topology. It is expected
// that the topology contains heterogeneous nodes.
type Evaluator interface {
Eval(report.Topology) report.Topology
}
// Expression is a single evaluator.
type Expression struct {
selector
transformer
}
// Eval implements Evaluator.
func (e Expression) Eval(tpy report.Topology) report.Topology {
return e.transformer(tpy, e.selector(tpy))
}
// Expressions is an ordered collection of expressions.
type Expressions []Expression
// Eval implements Evaluator.
func (e Expressions) Eval(tpy report.Topology) report.Topology {
for _, expr := range e {
tpy = expr.Eval(tpy)
}
return tpy
}
type selector func(report.Topology) []string
type transformer func(report.Topology, []string) report.Topology
func selectAll(tpy report.Topology) []string {
out := make([]string, 0, len(tpy.NodeMetadatas))
for id := range tpy.NodeMetadatas {
out = append(out, id)
}
log.Printf("select ALL: %d", len(out))
return out
}
func selectConnected(tpy report.Topology) []string {
degree := map[string]int{}
for src, dsts := range tpy.Adjacency {
a, ok := report.ParseAdjacencyID(src)
if !ok {
panic(src)
}
degree[a] += len(dsts)
for _, dst := range dsts {
degree[dst]++
}
}
out := []string{}
for id := range tpy.NodeMetadatas {
if degree[id] > 0 {
out = append(out, id)
}
}
log.Printf("select CONNECTED: %d", len(out))
return out
}
func selectNonlocal(tpy report.Topology) []string {
local := report.Networks{}
for _, md := range tpy.NodeMetadatas {
for k, v := range md.Metadata {
if k == host.LocalNetworks {
local = append(local, render.ParseNetworks(v)...)
}
}
}
out := []string{}
for id, md := range tpy.NodeMetadatas {
if addr, ok := md.Metadata[endpoint.Addr]; ok {
if ip := net.ParseIP(addr); ip != nil && !local.Contains(ip) {
out = append(out, id) // valid addr metadata key, nonlocal
continue
}
}
if _, addr, ok := report.ParseAddressNodeID(id); ok {
if ip := net.ParseIP(addr); ip != nil && !local.Contains(ip) {
out = append(out, id) // valid address node ID, nonlocal
continue
}
}
if _, addr, _, ok := report.ParseEndpointNodeID(id); ok {
if ip := net.ParseIP(addr); ip != nil && !local.Contains(ip) {
out = append(out, id) // valid endpoint node ID, nonlocal
continue
}
}
}
log.Printf("select NONLOCAL: %d", len(out))
return out
}
func selectLike(s string) selector {
re, err := regexp.Compile(s)
if err != nil {
log.Printf("select LIKE %q: %v", s, err)
re = regexp.MustCompile("")
}
return func(tpy report.Topology) []string {
out := []string{}
for id := range tpy.NodeMetadatas {
if re.MatchString(id) {
out = append(out, id)
}
}
log.Printf("select LIKE %q: %d", s, len(out))
return out
}
}
func selectWith(s string) selector {
var k, v string
if fields := strings.SplitN(s, "=", 2); len(fields) == 1 {
k = strings.TrimSpace(fields[0])
} else if len(fields) == 2 {
k, v = strings.TrimSpace(fields[0]), strings.TrimSpace(fields[1])
}
return func(tpy report.Topology) []string {
out := []string{}
for id, md := range tpy.NodeMetadatas {
if vv, ok := md.Metadata[k]; ok {
if v == "" || (v != "" && v == vv) {
out = append(out, id)
}
}
}
log.Printf("select WITH %q: %d", s, len(out))
return out
}
}
func selectNot(s selector) selector {
return func(tpy report.Topology) []string {
set := map[string]struct{}{}
for _, id := range s(tpy) {
set[id] = struct{}{}
}
out := []string{}
for id := range tpy.NodeMetadatas {
if _, ok := set[id]; ok {
continue // selected by that one -> not by this one
}
out = append(out, id)
}
log.Printf("select NOT: %d", len(out))
return out
}
}
const highlightKey = "_highlight"
func transformHighlight(tpy report.Topology, ids []string) report.Topology {
for _, id := range ids {
tpy.NodeMetadatas[id] = tpy.NodeMetadatas[id].Merge(report.MakeNodeMetadataWith(map[string]string{highlightKey: "true"}))
}
log.Printf("transform HIGHLIGHT %d: OK", len(ids))
return tpy
}
func transformRemove(tpy report.Topology, ids []string) report.Topology {
toRemove := map[string]struct{}{}
for _, id := range ids {
toRemove[id] = struct{}{}
}
out := report.MakeTopology()
for id := range tpy.NodeMetadatas {
if _, ok := toRemove[id]; ok {
continue
}
cp(out, tpy, id)
}
clean(out, toRemove)
log.Printf("transform REMOVE %d: in %d, out %d", len(ids), len(tpy.NodeMetadatas), len(out.NodeMetadatas))
return out
}
func transformShowOnly(tpy report.Topology, ids []string) report.Topology {
out := report.MakeTopology()
for _, id := range ids {
if _, ok := tpy.NodeMetadatas[id]; !ok {
continue
}
cp(out, tpy, id)
}
log.Printf("transform SHOWONLY %d: in %d, out %d", len(ids), len(tpy.NodeMetadatas), len(out.NodeMetadatas))
return out
}
func transformMerge(tpy report.Topology, ids []string) report.Topology {
name := fmt.Sprintf("%x", rand.Int31())
mapped := map[string]string{}
for _, id := range ids {
mapped[id] = name
}
out := report.MakeTopology()
for id := range tpy.NodeMetadatas {
if dstID, ok := mapped[id]; ok {
merge(out, dstID, tpy, id, mapped)
} else {
cp(out, tpy, id)
}
}
log.Printf("transform MERGE %d: in %d, out %d", len(ids), len(tpy.NodeMetadatas), len(out.NodeMetadatas))
return out
}
func transformGroupBy(s string) transformer {
keys := []string{}
for _, key := range strings.Split(s, ",") {
keys = append(keys, strings.TrimSpace(key))
}
return func(tpy report.Topology, ids []string) report.Topology {
set := map[string]struct{}{}
for _, id := range ids {
set[id] = struct{}{}
}
// Identify all nodes that should be grouped.
mapped := map[string]string{} // src ID: dst ID
for id, md := range tpy.NodeMetadatas {
if _, ok := set[id]; !ok {
continue // not selected
}
parts := []string{}
for _, key := range keys {
if val, ok := md.Metadata[key]; ok {
parts = append(parts, fmt.Sprintf("%s-%s", key, val))
}
}
if len(parts) < len(keys) {
continue // didn't match all required keys
}
dstID := strings.Join(parts, "-")
mapped[id] = dstID
}
// Walk nodes again, merging those that should be grouped.
out := report.MakeTopology()
for id := range tpy.NodeMetadatas {
if dstID, ok := mapped[id]; ok {
merge(out, dstID, tpy, id, mapped)
} else {
cp(out, tpy, id)
}
}
log.Printf("transform GROUPBY %v %d: in %d, out %d", keys, len(ids), len(tpy.NodeMetadatas), len(out.NodeMetadatas))
return out
}
}
func transformJoin(key string) transformer {
return func(tpy report.Topology, ids []string) report.Topology {
// key is e.g. host_node_id.
// Collect the set of represented values.
values := map[string]report.NodeMetadata{}
for _, md := range tpy.NodeMetadatas {
for k, v := range md.Metadata {
if k == key {
values[v] = report.MakeNodeMetadata() // gather later
}
}
}
// Next, gather the metadata from nodes in the set.
for id, md := range tpy.NodeMetadatas {
if found, ok := values[id]; ok {
values[id] = found.Merge(md) // gather
}
}
// Finally, join that metadata to referential nodes.
// And delete the referenced nodes.
out := report.MakeTopology()
for id, md := range tpy.NodeMetadatas {
if _, ok := values[id]; ok {
continue // delete
}
cp(out, tpy, id) // copy node
for k, v := range md.Metadata {
if k == key {
md = md.Merge(values[v]) // join metadata
}
}
out.NodeMetadatas[id] = md // write
}
log.Printf("transform JOIN %v %d: in %d, out %d", key, len(ids), len(tpy.NodeMetadatas), len(out.NodeMetadatas))
return out
}
}
func cp(dst report.Topology, src report.Topology, id string) {
adjacencyID := report.MakeAdjacencyID(id)
dst.Adjacency[adjacencyID] = src.Adjacency[adjacencyID]
for _, otherID := range dst.Adjacency[id] {
edgeID := report.MakeEdgeID(id, otherID)
dst.EdgeMetadatas[edgeID] = src.EdgeMetadatas[edgeID]
}
dst.NodeMetadatas[id] = src.NodeMetadatas[id]
}
func clean(dst report.Topology, toRemove map[string]struct{}) {
for srcAdjacencyID, dstIDs := range dst.Adjacency {
newIDs := report.IDList{}
for _, dstID := range dstIDs {
if _, ok := toRemove[dstID]; ok {
continue // can't be a dst anymore
}
newIDs = append(newIDs, dstID)
}
if len(newIDs) <= 0 {
delete(dst.Adjacency, srcAdjacencyID) // all dsts are gone, so rm src
continue
}
dst.Adjacency[srcAdjacencyID] = newIDs // overwrite
}
for id := range toRemove {
delete(dst.NodeMetadatas, id)
}
for edgeID := range dst.EdgeMetadatas {
srcNodeID, dstNodeID, ok := report.ParseEdgeID(edgeID)
if !ok {
continue // panic
}
if _, ok := toRemove[srcNodeID]; ok {
delete(dst.EdgeMetadatas, edgeID)
}
if _, ok := toRemove[dstNodeID]; ok {
delete(dst.EdgeMetadatas, edgeID)
}
}
}
func merge(dst report.Topology, dstID string, src report.Topology, srcID string, mapped map[string]string) {
// We gonna take srcID from src and merge it into dstID in dst. That's
// like renaming the node, so we gotta update the adjacency lists. Both
// outgoing *and* incoming links!
dstAdjacencyID := report.MakeAdjacencyID(dstID)
srcAdjacencyID := report.MakeAdjacencyID(srcID)
// Merge the src's adjacency list into the dst topology.
dst.Adjacency[dstAdjacencyID] = dst.Adjacency[dstAdjacencyID].Merge(src.Adjacency[srcAdjacencyID])
// Update any dst adjacencies from the old ID to the new ID.
for existingSrcAdjacencyID, existingDstIDs := range dst.Adjacency {
for i, existingDstID := range existingDstIDs {
if newDstID, ok := mapped[existingDstID]; ok {
existingDstIDs[i] = newDstID
}
}
dst.Adjacency[existingSrcAdjacencyID] = existingDstIDs
}
// Update the EdgeMetadatas to have the new IDs.
for _, otherID := range src.Adjacency[srcAdjacencyID] {
oldEdgeID := report.MakeEdgeID(srcID, otherID)
newEdgeID := report.MakeEdgeID(dstID, otherID)
dst.EdgeMetadatas[newEdgeID] = dst.EdgeMetadatas[newEdgeID].Merge(src.EdgeMetadatas[oldEdgeID])
}
// Merge the src node metadata into the dst node metadata.
md, ok := dst.NodeMetadatas[dstID]
if !ok {
md = report.MakeNodeMetadata()
}
md = md.Merge(src.NodeMetadatas[srcID])
dst.NodeMetadatas[dstID] = md
}