perf: reuse reverse proxy copy buffers

ecw_benchmark_test.go

@@ -0,0 +1,59 @@
+package touka
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestErrorCapturingResponseWriterResetClearsHeaderSnapshot(t *testing.T) {
+	c, _ := CreateTestContext(nil)
+	ecw := AcquireErrorCapturingResponseWriter(c)
+	defer ReleaseErrorCapturingResponseWriter(ecw)
+
+	ecw.capturedErrorSignal = true
+	ecw.Header().Set("Content-Type", "text/plain")
+	ecw.Header().Add("X-Test", "one")
+
+	req, err := http.NewRequest(http.MethodGet, "/", nil)
+	if err != nil {
+		t.Fatalf("failed to build request: %v", err)
+	}
+
+	ecw.reset(httptest.NewRecorder(), req, c, c.engine.errorHandle.handler)
+
+	if len(ecw.headerSnapshot) != 0 {
+		t.Fatalf("expected header snapshot to be empty after reset, got %#v", ecw.headerSnapshot)
+	}
+}
+
+func BenchmarkErrorCapturingResponseWriterReset(b *testing.B) {
+	c, _ := CreateTestContext(nil)
+	ecw := AcquireErrorCapturingResponseWriter(c)
+	defer ReleaseErrorCapturingResponseWriter(ecw)
+
+	rawWriter := httptest.NewRecorder()
+	req, err := http.NewRequest(http.MethodGet, "/", nil)
+	if err != nil {
+		b.Fatalf("failed to build request: %v", err)
+	}
+
+	keys := make([]string, 16)
+	for i := range keys {
+		keys[i] = http.CanonicalHeaderKey("X-Test-" + string(rune('A'+i)))
+	}
+	values := []string{"one", "two", "three"}
+	for _, key := range keys {
+		ecw.headerSnapshot[key] = values
+	}
+
+	b.ReportAllocs()
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		ecw.reset(rawWriter, req, c, c.engine.errorHandle.handler)
+		for _, key := range keys {
+			ecw.headerSnapshot[key] = values
+		}
+	}
+}