init

pkg/trace/trace.go

@@ -0,0 +1,32 @@
+package trace
+
+import (
+	"context"
+
+	"github.com/flamego/flamego"
+	"github.com/google/uuid"
+)
+
+type contextKey struct{}
+
+var activeSpanKey = contextKey{}
+
+func Context(ctx context.Context) context.Context {
+	x := uuid.New().String()
+	return context.WithValue(ctx, activeSpanKey, x)
+}
+
+func Trace(ctx context.Context) string {
+	traceValue := ctx.Value(activeSpanKey)
+	if trace, ok := traceValue.(string); ok {
+		return trace
+	}
+	return ""
+}
+
+func Tracer() flamego.ContextInvoker {
+	return func(ctx flamego.Context) {
+		r := ctx.Request().Clone(Context(context.Background()))
+		ctx.Map(r)
+	}
+}