Add OpenTracing span for report.ReadBinary()

So we can see the timing and size in Jaeger.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

app/benchmark_internal_test.go

@@ -30,7 +30,7 @@ func readReportFiles(b *testing.B, path string) []report.Report {
 			if info.IsDir() {
 				return nil
 			}
-			rpt, err := report.MakeFromFile(p)
+			rpt, err := report.MakeFromFile(context.Background(), p)
 			if err != nil {
 				return err
 			}

app/collector.go

@@ -278,7 +278,7 @@ func NewFileCollector(path string, window time.Duration) (Collector, error) {
 			}
 			timestamps = append(timestamps, t)
 
-			rpt, err := report.MakeFromFile(p)
+			rpt, err := report.MakeFromFile(context.Background(), p)
 			if err != nil {
 				return err
 			}

app/multitenant/s3_client.go

@@ -83,7 +83,7 @@ func (store *S3Store) fetchReport(ctx context.Context, key string) (*report.Repo
 		return nil, err
 	}
 	defer resp.Body.Close()
-	return report.MakeFromBinary(resp.Body)
+	return report.MakeFromBinary(ctx, resp.Body)
 }
 
 // StoreReportBytes stores a report.

app/router.go

@@ -140,7 +140,7 @@ func RegisterReportPostHandler(a Adder, router *mux.Router) {
 			return
 		}
 
-		if err := rpt.ReadBinary(reader, gzipped, handle); err != nil {
+		if err := rpt.ReadBinary(ctx, reader, gzipped, handle); err != nil {
 			respondWith(w, http.StatusBadRequest, err)
 			return
 		}

extras/copyreport/main.go

@@ -2,6 +2,7 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"log"
 
@@ -15,7 +16,7 @@ func main() {
 		log.Fatal("usage: copyreport src.(json|msgpack)[.gz] dst.(json|msgpack)[.gz]")
 	}
 
-	rpt, err := report.MakeFromFile(flag.Arg(0))
+	rpt, err := report.MakeFromFile(context.Background(), flag.Arg(0))
 	if err != nil {
 		log.Fatal(err)
 	}

report/marshal.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"bytes"
 	"compress/gzip"
+	"context"
 	"fmt"
 	"io"
 	"os"
@@ -11,6 +12,8 @@ import (
 	"strings"
 	"sync"
 
+	opentracing "github.com/opentracing/opentracing-go"
+	otlog "github.com/opentracing/opentracing-go/log"
 	log "github.com/sirupsen/logrus"
 	"github.com/ugorji/go/codec"
 )
@@ -73,7 +76,9 @@ var gzipWriterPool = &sync.Pool{
 //
 // Will decompress the binary if gzipped is true, and will use the given
 // codecHandle to decode it.
-func (rep *Report) ReadBinary(r io.Reader, gzipped bool, codecHandle codec.Handle) error {
+func (rep *Report) ReadBinary(ctx context.Context, r io.Reader, gzipped bool, codecHandle codec.Handle) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "report.ReadBinary")
+	defer span.Finish()
 	var err error
 	var compressedSize uint64
 
@@ -106,13 +111,14 @@ func (rep *Report) ReadBinary(r io.Reader, gzipped bool, codecHandle codec.Handl
 		uncompressedSize,
 		float32(compressedSize)/float32(uncompressedSize)*100,
 	)
+	span.LogFields(otlog.Uint64("compressedSize", compressedSize), otlog.Int64("uncompressedSize", uncompressedSize))
 	return nil
 }
 
 // MakeFromBinary constructs a Report from a gzipped msgpack.
-func MakeFromBinary(r io.Reader) (*Report, error) {
+func MakeFromBinary(ctx context.Context, r io.Reader) (*Report, error) {
 	rep := MakeReport()
-	if err := rep.ReadBinary(r, true, &codec.MsgpackHandle{}); err != nil {
+	if err := rep.ReadBinary(ctx, r, true, &codec.MsgpackHandle{}); err != nil {
 		return nil, err
 	}
 	return &rep, nil
@@ -153,7 +159,7 @@ func MakeFromBytes(buf []byte) (*Report, error) {
 // MakeFromFile construct a Report from a file, with the encoding
 // determined by the extension (".msgpack" or ".json", with an
 // optional ".gz").
-func MakeFromFile(path string) (rpt Report, _ error) {
+func MakeFromFile(ctx context.Context, path string) (rpt Report, _ error) {
 	f, err := os.Open(path)
 	if err != nil {
 		return rpt, err
@@ -165,7 +171,7 @@ func MakeFromFile(path string) (rpt Report, _ error) {
 		return rpt, err
 	}
 
-	err = rpt.ReadBinary(f, gzipped, handle)
+	err = rpt.ReadBinary(ctx, f, gzipped, handle)
 	return rpt, err
 }
 

report/marshal_test.go

@@ -1,6 +1,7 @@
 package report_test
 
 import (
+	"context"
 	"reflect"
 	"testing"
 	"time"
@@ -14,7 +15,7 @@ func TestRoundtrip(t *testing.T) {
 	r1 := report.MakeReport()
 	buf, _ := r1.WriteBinary()
 	bytes := append([]byte{}, buf.Bytes()...) // copy the contents for later
-	r2, err := report.MakeFromBinary(buf)
+	r2, err := report.MakeFromBinary(context.Background(), buf)
 	if err != nil {
 		t.Error(err)
 	}
@@ -71,7 +72,7 @@ func makeTestReport() report.Report {
 func TestBiggerRoundtrip(t *testing.T) {
 	r1 := makeTestReport()
 	buf, _ := r1.WriteBinary()
-	r2, err := report.MakeFromBinary(buf)
+	r2, err := report.MakeFromBinary(context.Background(), buf)
 	if err != nil {
 		t.Error(err)
 	}