Update sse.go

sse.go

@@ -1,6 +1,6 @@
 // This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
-// Copyright 2024 WJQSERVER. All rights reserved.
+// Copyright 2025 WJQSERVER. All rights reserved.
 // All rights reserved by WJQSERVER, related rights can be exercised by the infinite-iroha organization.
 package touka
 
@@ -25,6 +25,7 @@ type Event struct {
 }
 
 // Render 将事件格式化并写入给定的 writer.
+// 通过逐行处理数据, 此方法可防止因数据中包含换行符而导致的CRLF注入问题.
 // 为了性能, 它使用 bytes.Buffer 并通过 WriteTo 直接写入, 以避免不必要的内存分配.
 func (e *Event) Render(w io.Writer) error {
 	var buf bytes.Buffer
@@ -65,7 +66,6 @@ func (e *Event) Render(w io.Writer) error {
 // 这是推荐的、更简单安全的方式, 采用阻塞和回调的设计, 框架负责管理连接生命周期.
 //
 // 详细用法:
-//
 //  r.GET("/sse/callback", func(c *touka.Context) {
 //      // streamer 回调函数会在一个循环中被调用.
 //      c.EventStream(func(w io.Writer) bool {
@@ -86,19 +86,14 @@ func (e *Event) Render(w io.Writer) error {
 //      fmt.Println("Client disconnected from /sse/callback")
 //  })
 func (c *Context) EventStream(streamer func(w io.Writer) bool) {
-	c.Writer.Header().Set("Content-Type", "text/event-stream")
-	c.Writer.Header().Set("Cache-Control", "no-cache")
-	c.Writer.Header().Set("Connection", "keep-alive")
-	c.Writer.Header().Set("Transfer-Encoding", "chunked")
-
-	flusher, ok := c.Writer.(http.Flusher)
-	if !ok {
-		c.Errorf("streaming unsupported: http.ResponseWriter does not implement http.Flusher")
-		return
-	}
+	// 为现代网络协议优化头部.
+	c.Writer.Header().Set("Content-Type", "text/event-stream; charset=utf-8")
+	c.Writer.Header().Set("Cache-Control", "no-cache, no-transform")
+	c.Writer.Header().Del("Connection")
+	c.Writer.Header().Del("Transfer-Encoding")
 
 	c.Writer.WriteHeader(http.StatusOK)
-	flusher.Flush()
+	c.Writer.Flush() // 直接调用, ResponseWriter 接口保证了 Flush 方法的存在.
 
 	for {
 		select {
@@ -108,17 +103,20 @@ func (c *Context) EventStream(streamer func(w io.Writer) bool) {
 			if !streamer(c.Writer) {
 				return
 			}
-			flusher.Flush()
+			c.Writer.Flush()
 		}
 	}
 }
 
 // EventStreamChan 返回用于 SSE 事件流的 channel.
 // 这是为高级并发场景设计的、更灵活的API.
-// 调用者必须负责关闭 event channel 并处理 error channel 以避免 goroutine 泄漏.
+//
+// 重要:
+//  - 调用者必须 close(eventChan) 来结束事件流.
+//  - 调用者必须在独立的 goroutine 中消费 errChan 来处理错误和连接断开.
+//  - 为防止 goroutine 泄漏, 建议发送方在 select 中同时监听 c.Request.Context().Done().
 //
 // 详细用法:
-//
 //  r.GET("/sse/channel", func(c *touka.Context) {
 //      eventChan, errChan := c.EventStreamChan()
 //
@@ -135,36 +133,30 @@ func (c *Context) EventStream(streamer func(w io.Writer) bool) {
 //          defer close(eventChan)
 //
 //          for i := 1; i <= 5; i++ {
-//	            event := touka.Event{
+//              select {
+//              case <-c.Request.Context().Done():
+//                  return // 客户端已断开, 退出 goroutine.
+//              default:
+//                  eventChan <- touka.Event{
 //                      Id:   fmt.Sprintf("%d", i),
 //                      Data: "hello from channel",
 //                  }
-//	            eventChan <- event
 //                  time.Sleep(2 * time.Second)
 //              }
+//          }
 //      }()
 //  })
 func (c *Context) EventStreamChan() (chan<- Event, <-chan error) {
 	eventChan := make(chan Event)
 	errChan := make(chan error, 1)
 
-	c.Writer.Header().Set("Content-Type", "text/event-stream")
-	c.Writer.Header().Set("Cache-Control", "no-cache")
-	c.Writer.Header().Set("Connection", "keep-alive")
-	c.Writer.Header().Set("Transfer-Encoding", "chunked")
-
-	flusher, ok := c.Writer.(http.Flusher)
-	if !ok {
-		err := fmt.Errorf("streaming unsupported: http.ResponseWriter does not implement http.Flusher")
-		c.Errorf(err.Error())
-		errChan <- err
-		close(errChan)
-		close(eventChan)
-		return eventChan, errChan
-	}
+	c.Writer.Header().Set("Content-Type", "text/event-stream; charset=utf-8")
+	c.Writer.Header().Set("Cache-Control", "no-cache, no-transform")
+	c.Writer.Header().Del("Connection")
+	c.Writer.Header().Del("Transfer-Encoding")
 
 	c.Writer.WriteHeader(http.StatusOK)
-	flusher.Flush()
+	c.Writer.Flush() 
 
 	go func() {
 		defer close(errChan)
@@ -179,7 +171,7 @@ func (c *Context) EventStreamChan() (chan<- Event, <-chan error) {
 					errChan <- err
 					return
 				}
-				flusher.Flush()
+				c.Writer.Flush()
 			case <-c.Request.Context().Done():
 				errChan <- c.Request.Context().Err()
 				return