Initial QSfera import

Server/vendor/go-micro.dev/v4/debug/trace/default.go

@@ -0,0 +1,89 @@
+package trace
+
+import (
+	"context"
+	"time"
+
+	"github.com/google/uuid"
+	"go-micro.dev/v4/util/ring"
+)
+
+type memTracer struct {
+
+	// ring buffer of traces
+	buffer *ring.Buffer
+	opts   Options
+}
+
+func (t *memTracer) Read(opts ...ReadOption) ([]*Span, error) {
+	var options ReadOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	sp := t.buffer.Get(t.buffer.Size())
+
+	spans := make([]*Span, 0, len(sp))
+
+	for _, span := range sp {
+		val := span.Value.(*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 *memTracer) Start(ctx context.Context, name string) (context.Context, *Span) {
+	span := &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 ToContext(context.Background(), span.Trace, span.Id), span
+	}
+	traceID, parentSpanID, ok := FromContext(ctx)
+	// If the trace can not be found in the header,
+	// that means this is where the trace is created.
+	if !ok {
+		return ToContext(ctx, span.Trace, span.Id), span
+	}
+
+	// set trace id
+	span.Trace = traceID
+	// set parent
+	span.Parent = parentSpanID
+
+	// return the span
+	return ToContext(ctx, span.Trace, span.Id), span
+}
+
+func (t *memTracer) Finish(s *Span) error {
+	// set finished time
+	s.Duration = time.Since(s.Started)
+	// save the span
+	t.buffer.Put(s)
+
+	return nil
+}
+
+func NewTracer(opts ...Option) Tracer {
+	var options Options
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return &memTracer{
+		opts: options,
+		// the last 256 requests
+		buffer: ring.New(256),
+	}
+}