trace 1

debug/trace/trace.go

@@ -0,0 +1,48 @@
+// Package trace provides an interface for distributed tracing
+package trace
+
+import (
+	"context"
+	"time"
+)
+
+// Trace is an interface for distributed tracing
+type Trace interface {
+	// Start a trace
+	Start(ctx context.Context, name string) *Span
+	// Finish the trace
+	Finish(*Span) error
+	// Read the traces
+	Read(...ReadOption) ([]*Span, error)
+}
+
+// Span is used to record an entry
+type Span struct {
+	// Id of the trace
+	Trace string
+	// name of the span
+	Name string
+	// id of the span
+	Id string
+	// parent span id
+	Parent string
+	// Start time
+	Started time.Time
+	// Finish time
+	Finished time.Time
+	// associated data
+	Metadata map[string]string
+}
+
+type spanKey struct{}
+
+// FromContext returns a span from context
+func FromContext(ctx context.Context) (*Span, bool) {
+	s, ok := ctx.Value(spanKey{}).(*Span)
+	return s, ok
+}
+
+// NewContext creates a new context with the span
+func NewContext(ctx context.Context, s *Span) context.Context {
+	return context.WithValue(ctx, spanKey{}, s)
+}