refactor: Centralize stream handling and helper functions in relay package

relay/helper/common.go

@@ -0,0 +1,112 @@
+package helper
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"github.com/gin-gonic/gin"
+	"github.com/gorilla/websocket"
+	"net/http"
+	"one-api/common"
+	"one-api/dto"
+)
+
+func SetEventStreamHeaders(c *gin.Context) {
+	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")
+	c.Writer.Header().Set("X-Accel-Buffering", "no")
+}
+
+func StringData(c *gin.Context, str string) error {
+	//str = strings.TrimPrefix(str, "data: ")
+	//str = strings.TrimSuffix(str, "\r")
+	c.Render(-1, common.CustomEvent{Data: "data: " + str})
+	if flusher, ok := c.Writer.(http.Flusher); ok {
+		flusher.Flush()
+	} else {
+		return errors.New("streaming error: flusher not found")
+	}
+	return nil
+}
+
+func ObjectData(c *gin.Context, object interface{}) error {
+	jsonData, err := json.Marshal(object)
+	if err != nil {
+		return fmt.Errorf("error marshalling object: %w", err)
+	}
+	return StringData(c, string(jsonData))
+}
+
+func Done(c *gin.Context) {
+	_ = StringData(c, "[DONE]")
+}
+
+func WssString(c *gin.Context, ws *websocket.Conn, str string) error {
+	if ws == nil {
+		common.LogError(c, "websocket connection is nil")
+		return errors.New("websocket connection is nil")
+	}
+	//common.LogInfo(c, fmt.Sprintf("sending message: %s", str))
+	return ws.WriteMessage(1, []byte(str))
+}
+
+func WssObject(c *gin.Context, ws *websocket.Conn, object interface{}) error {
+	jsonData, err := json.Marshal(object)
+	if err != nil {
+		return fmt.Errorf("error marshalling object: %w", err)
+	}
+	if ws == nil {
+		common.LogError(c, "websocket connection is nil")
+		return errors.New("websocket connection is nil")
+	}
+	//common.LogInfo(c, fmt.Sprintf("sending message: %s", jsonData))
+	return ws.WriteMessage(1, jsonData)
+}
+
+func WssError(c *gin.Context, ws *websocket.Conn, openaiError dto.OpenAIError) {
+	errorObj := &dto.RealtimeEvent{
+		Type:    "error",
+		EventId: GetLocalRealtimeID(c),
+		Error:   &openaiError,
+	}
+	_ = WssObject(c, ws, errorObj)
+}
+
+func GetResponseID(c *gin.Context) string {
+	logID := c.GetString(common.RequestIdKey)
+	return fmt.Sprintf("chatcmpl-%s", logID)
+}
+
+func GetLocalRealtimeID(c *gin.Context) string {
+	logID := c.GetString(common.RequestIdKey)
+	return fmt.Sprintf("evt_%s", logID)
+}
+
+func GenerateStopResponse(id string, createAt int64, model string, finishReason string) *dto.ChatCompletionsStreamResponse {
+	return &dto.ChatCompletionsStreamResponse{
+		Id:                id,
+		Object:            "chat.completion.chunk",
+		Created:           createAt,
+		Model:             model,
+		SystemFingerprint: nil,
+		Choices: []dto.ChatCompletionsStreamResponseChoice{
+			{
+				FinishReason: &finishReason,
+			},
+		},
+	}
+}
+
+func GenerateFinalUsageResponse(id string, createAt int64, model string, usage dto.Usage) *dto.ChatCompletionsStreamResponse {
+	return &dto.ChatCompletionsStreamResponse{
+		Id:                id,
+		Object:            "chat.completion.chunk",
+		Created:           createAt,
+		Model:             model,
+		SystemFingerprint: nil,
+		Choices:           make([]dto.ChatCompletionsStreamResponseChoice, 0),
+		Usage:             &usage,
+	}
+}