Merge pull request #2736 from lucas-clemente/qlog-ndjson

use the new, streaming-friendly NDJSON-based qlog encoding

qlog/event.go

@@ -15,20 +15,6 @@ import (
 
 func milliseconds(dur time.Duration) float64 { return float64(dur.Nanoseconds()) / 1e6 }
 
-var eventFields = [4]string{"relative_time", "category", "event", "data"}
-
-type events []event
-
-var _ gojay.MarshalerJSONArray = events{}
-
-func (e events) IsNil() bool { return e == nil }
-
-func (e events) MarshalJSONArray(enc *gojay.Encoder) {
-	for _, ev := range e {
-		enc.Array(ev)
-	}
-}
-
 type eventDetails interface {
 	Category() category
 	Name() string
@@ -40,14 +26,13 @@ type event struct {
 	eventDetails
 }
 
-var _ gojay.MarshalerJSONArray = event{}
+var _ gojay.MarshalerJSONObject = event{}
 
 func (e event) IsNil() bool { return false }
-func (e event) MarshalJSONArray(enc *gojay.Encoder) {
-	enc.Float64(milliseconds(e.RelativeTime))
-	enc.String(e.Category().String())
-	enc.String(e.Name())
-	enc.Object(e.eventDetails)
+func (e event) MarshalJSONObject(enc *gojay.Encoder) {
+	enc.Float64Key("time", milliseconds(e.RelativeTime))
+	enc.StringKey("name", e.Category().String()+":"+e.Name())
+	enc.ObjectKey("data", e.eventDetails)
 }
 
 type versions []versionNumber

qlog/event_test.go

@@ -29,24 +29,15 @@ var _ = Describe("Events", func() {
 			eventDetails: mevent{},
 		})).To(Succeed())
 
-		var decoded []interface{}
+		var decoded interface{}
 		Expect(json.Unmarshal(buf.Bytes(), &decoded)).To(Succeed())
-		Expect(decoded).To(HaveLen(4))
-
-		// 1st field
-		Expect(eventFields[0]).To(Equal("relative_time"))
-		Expect(decoded[0].(float64)).To(Equal(1.337))
-
-		// 2nd field
-		Expect(eventFields[1]).To(Equal("category"))
-		Expect(decoded[1].(string)).To(Equal(categoryConnectivity.String()))
-
-		// 3rd field
-		Expect(eventFields[2]).To(Equal("event"))
-		Expect(decoded[2].(string)).To(Equal("mevent"))
-
-		// 4th field
-		Expect(eventFields[3]).To(Equal("data"))
-		Expect(decoded[3].(map[string]interface{})["event"]).To(Equal("details"))
+		Expect(decoded).To(HaveLen(3))
+
+		Expect(decoded).To(HaveKeyWithValue("time", 1.337))
+		Expect(decoded).To(HaveKeyWithValue("name", "connectivity:mevent"))
+		Expect(decoded).To(HaveKey("data"))
+		data := decoded.(map[string]interface{})["data"].(map[string]interface{})
+		Expect(data).To(HaveLen(1))
+		Expect(data).To(HaveKeyWithValue("event", "details"))
 	})
 })

qlog/qlog.go

@@ -50,7 +50,6 @@ type connectionTracer struct {
 	perspective   protocol.Perspective
 	referenceTime time.Time
 
-	suffix     []byte
 	events     chan event
 	encodeErr  error
 	runStopped chan struct{}
@@ -79,39 +78,36 @@ func (t *connectionTracer) run() {
 	buf := &bytes.Buffer{}
 	enc := gojay.NewEncoder(buf)
 	tl := &topLevel{
-		traces: traces{
-			{
-				VantagePoint: vantagePoint{Type: t.perspective},
-				CommonFields: commonFields{
-					ODCID:         connectionID(t.odcid),
-					GroupID:       connectionID(t.odcid),
-					ReferenceTime: t.referenceTime,
-				},
-				EventFields: eventFields[:],
+		trace: trace{
+			VantagePoint: vantagePoint{Type: t.perspective},
+			CommonFields: commonFields{
+				ODCID:         connectionID(t.odcid),
+				GroupID:       connectionID(t.odcid),
+				ReferenceTime: t.referenceTime,
 			},
 		},
 	}
 	if err := enc.Encode(tl); err != nil {
 		panic(fmt.Sprintf("qlog encoding into a bytes.Buffer failed: %s", err))
 	}
-	data := buf.Bytes()
-	t.suffix = data[buf.Len()-4:]
-	if _, err := t.w.Write(data[:buf.Len()-4]); err != nil {
+	if err := buf.WriteByte('\n'); err != nil {
+		panic(fmt.Sprintf("qlog encoding into a bytes.Buffer failed: %s", err))
+	}
+	if _, err := t.w.Write(buf.Bytes()); err != nil {
 		t.encodeErr = err
 	}
 	enc = gojay.NewEncoder(t.w)
-	isFirst := true
 	for ev := range t.events {
 		if t.encodeErr != nil { // if encoding failed, just continue draining the event channel
 			continue
 		}
-		if !isFirst {
-			t.w.Write([]byte(","))
-		}
 		if err := enc.Encode(ev); err != nil {
 			t.encodeErr = err
+			continue
+		}
+		if _, err := t.w.Write([]byte{'\n'}); err != nil {
+			t.encodeErr = err
 		}
-		isFirst = false
 	}
 }
 
@@ -128,9 +124,6 @@ func (t *connectionTracer) export() error {
 	if t.encodeErr != nil {
 		return t.encodeErr
 	}
-	if _, err := t.w.Write(t.suffix); err != nil {
-		return err
-	}
 	return t.w.Close()
 }