fix: reuse stream scanner buffer in channel handlers (#5225)

relay/channel/cloudflare/relay_cloudflare.go

@@ -30,7 +30,7 @@ func convertCf2CompletionsRequest(textRequest dto.GeneralOpenAIRequest) *CfReque
 }
 
 func cfStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*types.NewAPIError, *dto.Usage) {
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	scanner.Split(bufio.ScanLines)
 
 	helper.SetEventStreamHeaders(c)

relay/channel/cohere/relay-cohere.go

 package cohere
 
 import (
-	"bufio"
 	"encoding/json"
 	"io"
 	"net/http"
@@ -86,7 +85,7 @@ func cohereStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http
 	createdTime := common.GetTimestamp()
 	usage := &dto.Usage{}
 	responseText := ""
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	scanner.Split(func(data []byte, atEOF bool) (advance int, token []byte, err error) {
 		if atEOF && len(data) == 0 {
 			return 0, nil, nil
@@ -106,6 +105,9 @@ func cohereStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http
 			data := scanner.Text()
 			dataChan <- data
 		}
+		if err := scanner.Err(); err != nil {
+			common.SysLog("error reading stream: " + err.Error())
+		}
 		stopChan <- true
 	}()
 	helper.SetEventStreamHeaders(c)

relay/channel/coze/relay-coze.go

@@ -98,7 +98,7 @@ func cozeChatHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Res
 }
 
 func cozeChatStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*dto.Usage, *types.NewAPIError) {
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	scanner.Split(bufio.ScanLines)
 	helper.SetEventStreamHeaders(c)
 	id := helper.GetResponseID(c)

relay/channel/ollama/relay-ollama.go

 package ollama
 
 import (
-	"bufio"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -12,6 +11,7 @@ import (
 	"github.com/QuantumNous/new-api/common"
 	"github.com/QuantumNous/new-api/dto"
 	relaycommon "github.com/QuantumNous/new-api/relay/common"
+	"github.com/QuantumNous/new-api/relay/helper"
 	"github.com/QuantumNous/new-api/service"
 	"github.com/QuantumNous/new-api/types"
 
@@ -397,7 +397,7 @@ func PullOllamaModelStream(baseURL, apiKey, modelName string, progressCallback f
 	}
 
 	// 读取流式响应
-	scanner := bufio.NewScanner(response.Body)
+	scanner := helper.NewStreamScanner(response.Body)
 	successful := false
 	for scanner.Scan() {
 		line := scanner.Text()

relay/channel/ollama/stream.go

 package ollama
 
 import (
-	"bufio"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -70,7 +69,7 @@ func ollamaStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http
 	defer service.CloseResponseBodyGracefully(resp)
 
 	helper.SetEventStreamHeaders(c)
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	usage := &dto.Usage{}
 	var model = info.UpstreamModelName
 	var responseId = common.GetUUID()

relay/channel/tencent/relay-tencent.go

@@ -92,7 +92,7 @@ func streamResponseTencent2OpenAI(TencentResponse *TencentChatResponse) *dto.Cha
 
 func tencentStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*dto.Usage, *types.NewAPIError) {
 	var responseText string
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	scanner.Split(bufio.ScanLines)
 
 	helper.SetEventStreamHeaders(c)

relay/channel/zhipu/relay-zhipu.go

@@ -157,7 +157,7 @@ func streamMetaResponseZhipu2OpenAI(zhipuResponse *ZhipuStreamMetaResponse) (*dt
 
 func zhipuStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.Response) (*dto.Usage, *types.NewAPIError) {
 	var usage *dto.Usage
-	scanner := bufio.NewScanner(resp.Body)
+	scanner := helper.NewStreamScanner(resp.Body)
 	scanner.Split(bufio.ScanLines)
 	dataChan := make(chan string)
 	metaChan := make(chan string)
@@ -180,6 +180,9 @@ func zhipuStreamHandler(c *gin.Context, info *relaycommon.RelayInfo, resp *http.
 				}
 			}
 		}
+		if err := scanner.Err(); err != nil {
+			common.SysLog("error reading stream: " + err.Error())
+		}
 		stopChan <- true
 	}()
 	helper.SetEventStreamHeaders(c)

relay/helper/stream_scanner.go

@@ -34,6 +34,12 @@ func getScannerBufferSize() int {
 	return DefaultMaxScannerBufferSize
 }
 
+func NewStreamScanner(reader io.Reader) *bufio.Scanner {
+	scanner := bufio.NewScanner(reader)
+	scanner.Buffer(make([]byte, InitialScannerBufferSize), getScannerBufferSize())
+	return scanner
+}
+
 func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo, dataHandler func(data string, sr *StreamResult)) {
 
 	if resp == nil || dataHandler == nil {
@@ -54,7 +60,7 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 
 	var (
 		stopChan   = make(chan bool, 3) // 增加缓冲区避免阻塞
-		scanner    = bufio.NewScanner(resp.Body)
+		scanner    = NewStreamScanner(resp.Body)
 		ticker     = time.NewTicker(streamingTimeout)
 		pingTicker *time.Ticker
 		writeMutex sync.Mutex     // Mutex to protect concurrent writes
@@ -104,7 +110,6 @@ func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon
 		close(stopChan)
 	}()
 
-	scanner.Buffer(make([]byte, InitialScannerBufferSize), getScannerBufferSize())
 	scanner.Split(bufio.ScanLines)
 	SetEventStreamHeaders(c)
 

relay/helper/stream_scanner_test.go

 package helper
 
 import (
+	"bufio"
 	"fmt"
 	"io"
 	"net/http"
@@ -81,6 +82,22 @@ func TestStreamScannerHandler_NilInputs(t *testing.T) {
 	StreamScannerHandler(c, &http.Response{Body: io.NopCloser(strings.NewReader(""))}, info, nil)
 }
 
+func TestNewStreamScanner_AllowsLargeStreamLine(t *testing.T) {
+	oldBufferMB := constant.StreamScannerMaxBufferMB
+	constant.StreamScannerMaxBufferMB = 1
+	t.Cleanup(func() {
+		constant.StreamScannerMaxBufferMB = oldBufferMB
+	})
+
+	payload := strings.Repeat("x", 128<<10)
+	scanner := NewStreamScanner(strings.NewReader("data: " + payload + "\n"))
+	scanner.Split(bufio.ScanLines)
+
+	require.True(t, scanner.Scan())
+	assert.Equal(t, "data: "+payload, scanner.Text())
+	require.NoError(t, scanner.Err())
+}
+
 func TestStreamScannerHandler_EmptyBody(t *testing.T) {
 	t.Parallel()