From 6135085d619dc918fd26994c7ad285d042d9c26a Mon Sep 17 00:00:00 2001
From: jianchenma <jianchenma@qq.com>
Date: Wed, 3 Feb 2021 15:27:41 +0800
Subject: [PATCH] improve package gtrace

---
 net/ghttp/ghttp_middleware_tracing.go       |  2 +-
 net/ghttp/internal/client/client_tracing.go |  2 +-
 net/gtrace/gtrace.go                        | 17 +++++++++++++++--
 net/gtrace/gtrace_unit_carrier_test.go      |  5 +++--
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/net/ghttp/ghttp_middleware_tracing.go b/net/ghttp/ghttp_middleware_tracing.go
index f8b19122b..22b4cdc2b 100644
--- a/net/ghttp/ghttp_middleware_tracing.go
+++ b/net/ghttp/ghttp_middleware_tracing.go
@@ -41,7 +41,7 @@ func MiddlewareClientTracing(c *Client, r *http.Request) (*ClientResponse, error
 // MiddlewareServerTracing is a serer middleware that enables tracing feature using standards of OpenTelemetry.
 func MiddlewareServerTracing(r *Request) {
 	tr := otel.GetTracerProvider().Tracer(tracingInstrumentName, trace.WithInstrumentationVersion(gf.VERSION))
-	ctx := gtrace.DefaultTextMapPropagator().Extract(r.Context(), r.Header)
+	ctx := otel.GetTextMapPropagator().Extract(r.Context(), r.Header)
 	ctx, span := tr.Start(ctx, r.URL.String(), trace.WithSpanKind(trace.SpanKindServer))
 	defer span.End()
 
diff --git a/net/ghttp/internal/client/client_tracing.go b/net/ghttp/internal/client/client_tracing.go
index 5f7e914bb..244ea05b9 100644
--- a/net/ghttp/internal/client/client_tracing.go
+++ b/net/ghttp/internal/client/client_tracing.go
@@ -48,7 +48,7 @@ func MiddlewareTracing(c *Client, r *http.Request) (response *Response, err erro
 	span.SetAttributes(gtrace.CommonLabels()...)
 
 	// Inject tracing content into http header.
-	gtrace.DefaultTextMapPropagator().Inject(ctx, r.Header)
+	otel.GetTextMapPropagator().Inject(ctx, r.Header)
 
 	// Continue client handler executing.
 	response, err = c.Next(
diff --git a/net/gtrace/gtrace.go b/net/gtrace/gtrace.go
index aaa1b3e68..a166ddcb0 100644
--- a/net/gtrace/gtrace.go
+++ b/net/gtrace/gtrace.go
@@ -12,6 +12,7 @@ import (
 	"github.com/gogf/gf/container/gmap"
 	"github.com/gogf/gf/container/gvar"
 	"github.com/gogf/gf/net/gipv4"
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/label"
 	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
@@ -35,6 +36,10 @@ var (
 	)
 )
 
+func init() {
+	CheckSetDefaultTextMapPropagator()
+}
+
 // CommonLabels returns common used attribute labels:
 // ip.intranet, hostname.
 func CommonLabels() []label.KeyValue {
@@ -49,8 +54,16 @@ func IsActivated(ctx context.Context) bool {
 	return GetTraceId(ctx) != ""
 }
 
-// DefaultTextMapPropagator returns the default propagator for context propagation between peers.
-func DefaultTextMapPropagator() propagation.TextMapPropagator {
+// CheckSetDefaultTextMapPropagator sets the default TextMapPropagator if it is not set previously.
+func CheckSetDefaultTextMapPropagator() {
+	p := otel.GetTextMapPropagator()
+	if len(p.Fields()) == 0 {
+		otel.SetTextMapPropagator(GetDefaultTextMapPropagator())
+	}
+}
+
+// GetDefaultTextMapPropagator returns the default propagator for context propagation between peers.
+func GetDefaultTextMapPropagator() propagation.TextMapPropagator {
 	return defaultTextMapPropagator
 }
 
diff --git a/net/gtrace/gtrace_unit_carrier_test.go b/net/gtrace/gtrace_unit_carrier_test.go
index 81080815c..85720a3ba 100644
--- a/net/gtrace/gtrace_unit_carrier_test.go
+++ b/net/gtrace/gtrace_unit_carrier_test.go
@@ -10,6 +10,7 @@ import (
 	"context"
 	"github.com/gogf/gf/net/gtrace"
 	"github.com/gogf/gf/test/gtest"
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/oteltest"
 	"go.opentelemetry.io/otel/trace"
 	"testing"
@@ -52,10 +53,10 @@ func TestNewCarrier(t *testing.T) {
 		})
 		ctx, _ = oteltest.DefaultTracer().Start(ctx, "inject")
 		carrier1 := gtrace.NewCarrier()
-		gtrace.DefaultTextMapPropagator().Inject(ctx, carrier1)
+		otel.GetTextMapPropagator().Inject(ctx, carrier1)
 		t.Assert(carrier1.String(), `{"traceparent":"00-4bf92f3577b34da6a3ce929d0e0e4736-0000000000000002-01","tracestate":""}`)
 
-		ctx = gtrace.DefaultTextMapPropagator().Extract(ctx, carrier1)
+		ctx = otel.GetTextMapPropagator().Extract(ctx, carrier1)
 		gotSc := trace.RemoteSpanContextFromContext(ctx)
 		t.Assert(gotSc.TraceID.String(), traceID.String())
 		t.Assert(gotSc.SpanID.String(), "0000000000000002")