refactor: Centralize stream handling and helper functions in relay package

relay/helper/stream_scanner.go

@@ -0,0 +1,85 @@
+package helper
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"net/http"
+	"one-api/common"
+	"one-api/constant"
+	relaycommon "one-api/relay/common"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+func StreamScannerHandler(c *gin.Context, resp *http.Response, info *relaycommon.RelayInfo, dataHandler func(data string) bool) {
+
+	streamingTimeout := time.Duration(constant.StreamingTimeout) * time.Second
+	if strings.HasPrefix(info.UpstreamModelName, "o1") || strings.HasPrefix(info.UpstreamModelName, "o3") {
+		// twice timeout for thinking model
+		streamingTimeout *= 2
+	}
+
+	var (
+		stopChan = make(chan bool, 2)
+		scanner  = bufio.NewScanner(resp.Body)
+		ticker   = time.NewTicker(streamingTimeout)
+	)
+
+	defer func() {
+		ticker.Stop()
+		close(stopChan)
+	}()
+
+	scanner.Split(bufio.ScanLines)
+	SetEventStreamHeaders(c)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	ctx = context.WithValue(ctx, "stop_chan", stopChan)
+	common.RelayCtxGo(ctx, func() {
+		for scanner.Scan() {
+			ticker.Reset(streamingTimeout)
+			data := scanner.Text()
+			if common.DebugEnabled {
+				println(data)
+			}
+
+			if len(data) < 6 {
+				continue
+			}
+			if data[:5] != "data:" && data[:6] != "[DONE]" {
+				continue
+			}
+			data = data[5:]
+			data = strings.TrimLeft(data, " ")
+			data = strings.TrimSuffix(data, "\"")
+			if !strings.HasPrefix(data, "[DONE]") {
+				info.SetFirstResponseTime()
+				success := dataHandler(data)
+				if !success {
+					break
+				}
+			}
+		}
+
+		if err := scanner.Err(); err != nil {
+			if err != io.EOF {
+				common.LogError(c, "scanner error: "+err.Error())
+			}
+		}
+
+		common.SafeSendBool(stopChan, true)
+	})
+
+	select {
+	case <-ticker.C:
+		// 超时处理逻辑
+		common.LogError(c, "streaming timeout")
+	case <-stopChan:
+		// 正常结束
+	}
+}