feat: send SSE ping before get response

relay/channel/api_request.go

@@ -1,16 +1,23 @@
 package channel
 
 import (
+	"context"
 	"errors"
 	"fmt"
-	"github.com/gin-gonic/gin"
-	"github.com/gorilla/websocket"
 	"io"
 	"net/http"
 	common2 "one-api/common"
 	"one-api/relay/common"
 	"one-api/relay/constant"
+	"one-api/relay/helper"
 	"one-api/service"
+	"one-api/setting/operation_setting"
+	"sync"
+	"time"
+
+	"github.com/bytedance/gopkg/util/gopool"
+	"github.com/gin-gonic/gin"
+	"github.com/gorilla/websocket"
 )
 
 func SetupApiRequestHeader(info *common.RelayInfo, c *gin.Context, req *http.Header) {
@@ -105,7 +112,62 @@ func doRequest(c *gin.Context, req *http.Request, info *common.RelayInfo) (*http
 	} else {
 		client = service.GetHttpClient()
 	}
+	// 流式请求 ping 保活
+	var stopPinger func()
+	generalSettings := operation_setting.GetGeneralSetting()
+	pingEnabled := generalSettings.PingIntervalEnabled
+	var pingerWg sync.WaitGroup
+	if info.IsStream {
+		helper.SetEventStreamHeaders(c)
+		pingInterval := time.Duration(generalSettings.PingIntervalSeconds) * time.Second
+		var pingerCtx context.Context
+		pingerCtx, stopPinger = context.WithCancel(c.Request.Context())
+
+		if pingEnabled {
+			pingerWg.Add(1)
+			gopool.Go(func() {
+				defer pingerWg.Done()
+				if pingInterval <= 0 {
+					pingInterval = helper.DefaultPingInterval
+				}
+
+				ticker := time.NewTicker(pingInterval)
+				defer ticker.Stop()
+				var pingMutex sync.Mutex
+				if common2.DebugEnabled {
+					println("SSE ping goroutine started")
+				}
+
+				for {
+					select {
+					case <-ticker.C:
+						pingMutex.Lock()
+						err2 := helper.PingData(c)
+						pingMutex.Unlock()
+						if err2 != nil {
+							common2.LogError(c, "SSE ping error: "+err.Error())
+							return
+						}
+						if common2.DebugEnabled {
+							println("SSE ping data sent.")
+						}
+					case <-pingerCtx.Done():
+						if common2.DebugEnabled {
+							println("SSE ping goroutine stopped.")
+						}
+						return
+					}
+				}
+			})
+		}
+	}
+
 	resp, err := client.Do(req)
+	// request结束后停止ping
+	if info.IsStream && pingEnabled {
+		stopPinger()
+		pingerWg.Wait()
+	}
 	if err != nil {
 		return nil, err
 	}