Refactor debug/trace ready for Jaeger

debug/trace/memory/memory.go

@@ -0,0 +1,90 @@
+package memory
+
+import (
+	"context"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/micro/go-micro/debug/trace"
+	"github.com/micro/go-micro/util/ring"
+)
+
+type Tracer struct {
+	opts trace.Options
+
+	// ring buffer of traces
+	buffer *ring.Buffer
+}
+
+func (t *Tracer) Read(opts ...trace.ReadOption) ([]*trace.Span, error) {
+	var options trace.ReadOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	sp := t.buffer.Get(t.buffer.Size())
+
+	var spans []*trace.Span
+
+	for _, span := range sp {
+		val := span.Value.(*trace.Span)
+		// skip if trace id is specified and doesn't match
+		if len(options.Trace) > 0 && val.Trace != options.Trace {
+			continue
+		}
+		spans = append(spans, val)
+	}
+
+	return spans, nil
+}
+
+func (t *Tracer) Start(ctx context.Context, name string) (context.Context, *trace.Span) {
+	span := &trace.Span{
+		Name:     name,
+		Trace:    uuid.New().String(),
+		Id:       uuid.New().String(),
+		Started:  time.Now(),
+		Metadata: make(map[string]string),
+	}
+
+	// return span if no context
+	if ctx == nil {
+		return context.Background(), span
+	}
+
+	s, ok := trace.FromContext(ctx)
+	if !ok {
+		return ctx, span
+	}
+
+	// set trace id
+	span.Trace = s.Trace
+	// set parent
+	span.Parent = s.Id
+
+	// return the sapn
+	return ctx, span
+}
+
+func (t *Tracer) Finish(s *trace.Span) error {
+	// set finished time
+	s.Duration = time.Since(s.Started)
+
+	// save the span
+	t.buffer.Put(s)
+
+	return nil
+}
+
+func NewTracer(opts ...trace.Option) trace.Tracer {
+	var options trace.Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return &Tracer{
+		opts: options,
+		// the last 64 requests
+		buffer: ring.New(64),
+	}
+}