From 34e522306de5183fa5b52381e186064bc00f6df7 Mon Sep 17 00:00:00 2001
From: ltp217 <867813857@qq.com>
Date: Tue, 17 Oct 2023 20:35:56 +0800
Subject: [PATCH] resolve response is gzip in internalMiddlewareServerTracing
 (#3055)

---
 net/ghttp/ghttp_middleware_tracing.go         | 28 ++++++++++++
 ...tp_z_unit_feature_middleware_basic_test.go | 44 +++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/net/ghttp/ghttp_middleware_tracing.go b/net/ghttp/ghttp_middleware_tracing.go
index 98950fa94..08c71f45e 100644
--- a/net/ghttp/ghttp_middleware_tracing.go
+++ b/net/ghttp/ghttp_middleware_tracing.go
@@ -7,9 +7,12 @@
 package ghttp
 
 import (
+	"compress/gzip"
 	"context"
 	"fmt"
 	"io"
+	"net/http"
+	"strings"
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
@@ -110,9 +113,34 @@ func internalMiddlewareServerTracing(r *Request) {
 	}
 	// Response content logging.
 	var resBodyContent = gstr.StrLimit(r.Response.BufferString(), gtrace.MaxContentLogSize(), "...")
+	if gzipAccepted(r.Response.Header()) {
+		reader, err := gzip.NewReader(strings.NewReader(r.Response.BufferString()))
+		if err != nil {
+			span.SetStatus(codes.Error, fmt.Sprintf(`read gzip response err:%+v`, err))
+		}
+		defer reader.Close()
+		uncompressed, err := io.ReadAll(reader)
+		if err != nil {
+			span.SetStatus(codes.Error, fmt.Sprintf(`get uncompress value err:%+v`, err))
+		}
+		resBodyContent = gstr.StrLimit(string(uncompressed), gtrace.MaxContentLogSize(), "...")
+	}
 
 	span.AddEvent(tracingEventHttpResponse, trace.WithAttributes(
 		attribute.String(tracingEventHttpResponseHeaders, gconv.String(httputil.HeaderToMap(r.Response.Header()))),
 		attribute.String(tracingEventHttpResponseBody, resBodyContent),
 	))
 }
+
+// gzipAccepted returns whether the client will accept gzip-encoded content.
+func gzipAccepted(header http.Header) bool {
+	a := header.Get("Content-Encoding")
+	parts := strings.Split(a, ",")
+	for _, part := range parts {
+		part = strings.TrimSpace(part)
+		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
+			return true
+		}
+	}
+	return false
+}
diff --git a/net/ghttp/ghttp_z_unit_feature_middleware_basic_test.go b/net/ghttp/ghttp_z_unit_feature_middleware_basic_test.go
index ebbc83d11..ac1985163 100644
--- a/net/ghttp/ghttp_z_unit_feature_middleware_basic_test.go
+++ b/net/ghttp/ghttp_z_unit_feature_middleware_basic_test.go
@@ -7,8 +7,10 @@
 package ghttp_test
 
 import (
+	"compress/gzip"
 	"fmt"
 	"net/http"
+	"strings"
 	"testing"
 	"time"
 
@@ -17,6 +19,8 @@ import (
 	"github.com/gogf/gf/v2/net/ghttp"
 	"github.com/gogf/gf/v2/test/gtest"
 	"github.com/gogf/gf/v2/util/guid"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/trace"
 )
 
 func Test_BindMiddleware_Basic1(t *testing.T) {
@@ -736,3 +740,43 @@ func Test_MiddlewareHandlerResponse(t *testing.T) {
 		t.Assert(rsp.StatusCode, http.StatusInternalServerError)
 	})
 }
+
+func Test_MiddlewareHandlerGzipResponse(t *testing.T) {
+	tp := testTracerProvider{}
+	otel.SetTracerProvider(&tp)
+	s := g.Server(guid.S())
+	s.Group("/", func(group *ghttp.RouterGroup) {
+		group.GET("/default", func(r *ghttp.Request) {
+			var buffer strings.Builder
+			gzipWriter := gzip.NewWriter(&buffer)
+			defer gzipWriter.Close()
+			_, _ = gzipWriter.Write([]byte("hello"))
+			// 设置响应头，表明内容使用 gzip 压缩
+			r.Response.Header().Set("Content-Encoding", "gzip")
+			r.Response.Header().Set("Content-Encoding", "gzip")
+			r.Response.Header().Set("Content-Type", "text/plain")
+			r.Response.Header().Set("Content-Length", fmt.Sprint(buffer.Len()))
+			// 写入压缩后的内容
+			r.Response.Write(buffer.String())
+		})
+	})
+	s.SetDumpRouterMap(false)
+	s.Start()
+	defer s.Shutdown()
+	time.Sleep(100 * time.Millisecond)
+	gtest.C(t, func(t *gtest.T) {
+		client := g.Client()
+		client.SetPrefix(fmt.Sprintf("http://127.0.0.1:%d", s.GetListenedPort()))
+		rsp, err := client.Get(ctx, "/default")
+		t.AssertNil(err)
+		t.Assert(rsp.StatusCode, http.StatusOK)
+	})
+}
+
+type testTracerProvider struct{}
+
+var _ trace.TracerProvider = &testTracerProvider{}
+
+func (*testTracerProvider) Tracer(_ string, _ ...trace.TracerOption) trace.Tracer {
+	return trace.NewNoopTracerProvider().Tracer("")
+}