qlog: split serializiation and event definitions, remove logging abstraction (#5356)

* qlog: implement a Trace and a Writer struct

* qlog: rename Trace to FileSeq

* split qlog trace writer and QUIC qlog events into separate packages

* use the new qlog.Recorder instead of the logging.ConnectionTracer

qlogwriter/trace_test.go

@@ -0,0 +1,108 @@
+package qlogwriter
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"os"
+	"strconv"
+	"testing"
+	"time"
+
+	"github.com/quic-go/quic-go/internal/protocol"
+
+	"github.com/stretchr/testify/require"
+)
+
+type nopWriteCloserImpl struct{ io.Writer }
+
+func (nopWriteCloserImpl) Close() error { return nil }
+
+func nopWriteCloser(w io.Writer) io.WriteCloser {
+	return &nopWriteCloserImpl{Writer: w}
+}
+
+func scaleDuration(t time.Duration) time.Duration {
+	scaleFactor := 1
+	if f, err := strconv.Atoi(os.Getenv("TIMESCALE_FACTOR")); err == nil { // parsing "" errors, so this works fine if the env is not set
+		scaleFactor = f
+	}
+	if scaleFactor == 0 {
+		panic("TIMESCALE_FACTOR must not be 0")
+	}
+	return time.Duration(scaleFactor) * t
+}
+
+func unmarshal(data []byte, v any) error {
+	if bytes.Equal(data[:1], recordSeparator) {
+		data = data[1:]
+	}
+	return json.Unmarshal(data, v)
+}
+
+func newTracer() (Trace, *bytes.Buffer) {
+	buf := &bytes.Buffer{}
+	trace := NewFileSeq(nopWriteCloser(buf))
+	go trace.Run()
+	return trace, buf
+}
+
+func TestTraceMetadata(t *testing.T) {
+	trace, buf := newTracer()
+	producer := trace.AddProducer()
+	producer.Close()
+
+	var m map[string]any
+	require.NoError(t, unmarshal(buf.Bytes(), &m))
+	require.Equal(t, "0.3", m["qlog_version"])
+	require.Contains(t, m, "title")
+	require.Contains(t, m, "trace")
+	tr := m["trace"].(map[string]any)
+	require.Contains(t, tr, "common_fields")
+	commonFields := tr["common_fields"].(map[string]any)
+	require.NotContains(t, commonFields, "ODCID")
+	require.NotContains(t, commonFields, "group_id")
+	require.Contains(t, commonFields, "reference_time")
+	referenceTime := time.Unix(0, int64(commonFields["reference_time"].(float64)*1e6))
+	require.WithinDuration(t, time.Now(), referenceTime, scaleDuration(10*time.Millisecond))
+	require.Equal(t, "relative", commonFields["time_format"])
+	require.Contains(t, tr, "vantage_point")
+	vantagePoint := tr["vantage_point"].(map[string]any)
+	require.Equal(t, "transport", vantagePoint["type"])
+}
+
+func newConnectionTracer(t *testing.T) (Recorder, *bytes.Buffer) {
+	buf := &bytes.Buffer{}
+	trace := NewConnectionFileSeq(
+		nopWriteCloser(buf),
+		false,
+		protocol.ParseConnectionID([]byte{0xde, 0xad, 0xbe, 0xef}),
+	)
+	go trace.Run()
+	recorder := trace.AddProducer()
+	t.Cleanup(func() { recorder.Close() })
+	return recorder, buf
+}
+
+func TestConnectionTraceMetadata(t *testing.T) {
+	tracer, buf := newConnectionTracer(t)
+	tracer.Close()
+
+	m := make(map[string]any)
+	require.NoError(t, unmarshal(buf.Bytes(), &m))
+	require.Equal(t, "0.3", m["qlog_version"])
+	require.Contains(t, m, "title")
+	require.Contains(t, m, "trace")
+	trace := m["trace"].(map[string]any)
+	require.Contains(t, trace, "common_fields")
+	commonFields := trace["common_fields"].(map[string]any)
+	require.Equal(t, "deadbeef", commonFields["ODCID"])
+	require.Equal(t, "deadbeef", commonFields["group_id"])
+	require.Contains(t, commonFields, "reference_time")
+	referenceTime := time.Unix(0, int64(commonFields["reference_time"].(float64)*1e6))
+	require.WithinDuration(t, time.Now(), referenceTime, scaleDuration(10*time.Millisecond))
+	require.Equal(t, "relative", commonFields["time_format"])
+	require.Contains(t, trace, "vantage_point")
+	vantagePoint := trace["vantage_point"].(map[string]any)
+	require.Equal(t, "server", vantagePoint["type"])
+}