feat(platform-api): return traceable timeout errors

vehicle-data-platform/apps/api/internal/app/server.go

@@ -1,13 +1,16 @@
 package app
 
 import (
+	"bytes"
 	"context"
 	"database/sql"
 	"log"
 	"net/http"
+	"sync"
 	"time"
 
 	"lingniu/vehicle-data-platform/apps/api/internal/config"
+	"lingniu/vehicle-data-platform/apps/api/internal/httpx"
 	"lingniu/vehicle-data-platform/apps/api/internal/platform"
 	"lingniu/vehicle-data-platform/apps/api/internal/static"
 )
@@ -42,5 +45,71 @@ func withRequestTimeout(next http.Handler, timeout time.Duration) http.Handler {
 	if timeout <= 0 {
 		return next
 	}
-	return http.TimeoutHandler(next, timeout, `{"error":{"code":"REQUEST_TIMEOUT","message":"请求处理超时"},"traceId":"timeout","timestamp":0}`)
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ctx, cancel := context.WithTimeout(r.Context(), timeout)
+		defer cancel()
+		buffered := newBufferedResponseWriter()
+		result := make(chan any, 1)
+		go func() {
+			defer func() {
+				result <- recover()
+			}()
+			next.ServeHTTP(buffered, r.WithContext(ctx))
+		}()
+		select {
+		case panicValue := <-result:
+			if panicValue != nil {
+				panic(panicValue)
+			}
+			buffered.writeTo(w)
+		case <-ctx.Done():
+			httpx.WriteError(w, http.StatusServiceUnavailable, "REQUEST_TIMEOUT", "请求处理超时", "", requestTraceID(r))
+		}
+	})
+}
+
+func requestTraceID(r *http.Request) string {
+	if value := r.Header.Get("X-Trace-Id"); value != "" {
+		return value
+	}
+	return "trace-" + time.Now().Format("20060102150405.000000")
+}
+
+type bufferedResponseWriter struct {
+	mu     sync.Mutex
+	header http.Header
+	status int
+	body   bytes.Buffer
+}
+
+func newBufferedResponseWriter() *bufferedResponseWriter {
+	return &bufferedResponseWriter{header: http.Header{}, status: http.StatusOK}
+}
+
+func (w *bufferedResponseWriter) Header() http.Header {
+	return w.header
+}
+
+func (w *bufferedResponseWriter) WriteHeader(statusCode int) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	w.status = statusCode
+}
+
+func (w *bufferedResponseWriter) Write(body []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	return w.body.Write(body)
+}
+
+func (w *bufferedResponseWriter) writeTo(target http.ResponseWriter) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	for key, values := range w.header {
+		for _, value := range values {
+			target.Header().Add(key, value)
+		}
+	}
+	target.WriteHeader(w.status)
+	_, _ = target.Write(w.body.Bytes())
 }