package memory import ( "context" "time" "github.com/google/uuid" "github.com/unistack-org/micro/v3/debug/trace" "github.com/unistack-org/micro/v3/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()) spans := make([]*trace.Span, 0, len(sp)) 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 trace.ToContext(context.Background(), span.Trace, span.Id), span } traceID, parentSpanID, ok := trace.FromContext(ctx) // If the trace can not be found in the header, // that means this is where the trace is created. if !ok { return trace.ToContext(ctx, span.Trace, span.Id), span } // set trace id span.Trace = traceID // set parent span.Parent = parentSpanID // return the span return trace.ToContext(ctx, span.Trace, span.Id), 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 256 requests buffer: ring.New(256), } }