refactor: refactor relay part (#935)

relay/channel/anthropic/main.go

@@ -0,0 +1,196 @@
+package anthropic
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"github.com/gin-gonic/gin"
+	"io"
+	"net/http"
+	"one-api/common"
+	"one-api/relay/channel/openai"
+	"strings"
+)
+
+func stopReasonClaude2OpenAI(reason string) string {
+	switch reason {
+	case "stop_sequence":
+		return "stop"
+	case "max_tokens":
+		return "length"
+	default:
+		return reason
+	}
+}
+
+func ConvertRequest(textRequest openai.GeneralOpenAIRequest) *Request {
+	claudeRequest := Request{
+		Model:             textRequest.Model,
+		Prompt:            "",
+		MaxTokensToSample: textRequest.MaxTokens,
+		StopSequences:     nil,
+		Temperature:       textRequest.Temperature,
+		TopP:              textRequest.TopP,
+		Stream:            textRequest.Stream,
+	}
+	if claudeRequest.MaxTokensToSample == 0 {
+		claudeRequest.MaxTokensToSample = 1000000
+	}
+	prompt := ""
+	for _, message := range textRequest.Messages {
+		if message.Role == "user" {
+			prompt += fmt.Sprintf("\n\nHuman: %s", message.Content)
+		} else if message.Role == "assistant" {
+			prompt += fmt.Sprintf("\n\nAssistant: %s", message.Content)
+		} else if message.Role == "system" {
+			if prompt == "" {
+				prompt = message.StringContent()
+			}
+		}
+	}
+	prompt += "\n\nAssistant:"
+	claudeRequest.Prompt = prompt
+	return &claudeRequest
+}
+
+func streamResponseClaude2OpenAI(claudeResponse *Response) *openai.ChatCompletionsStreamResponse {
+	var choice openai.ChatCompletionsStreamResponseChoice
+	choice.Delta.Content = claudeResponse.Completion
+	finishReason := stopReasonClaude2OpenAI(claudeResponse.StopReason)
+	if finishReason != "null" {
+		choice.FinishReason = &finishReason
+	}
+	var response openai.ChatCompletionsStreamResponse
+	response.Object = "chat.completion.chunk"
+	response.Model = claudeResponse.Model
+	response.Choices = []openai.ChatCompletionsStreamResponseChoice{choice}
+	return &response
+}
+
+func responseClaude2OpenAI(claudeResponse *Response) *openai.TextResponse {
+	choice := openai.TextResponseChoice{
+		Index: 0,
+		Message: openai.Message{
+			Role:    "assistant",
+			Content: strings.TrimPrefix(claudeResponse.Completion, " "),
+			Name:    nil,
+		},
+		FinishReason: stopReasonClaude2OpenAI(claudeResponse.StopReason),
+	}
+	fullTextResponse := openai.TextResponse{
+		Id:      fmt.Sprintf("chatcmpl-%s", common.GetUUID()),
+		Object:  "chat.completion",
+		Created: common.GetTimestamp(),
+		Choices: []openai.TextResponseChoice{choice},
+	}
+	return &fullTextResponse
+}
+
+func StreamHandler(c *gin.Context, resp *http.Response) (*openai.ErrorWithStatusCode, string) {
+	responseText := ""
+	responseId := fmt.Sprintf("chatcmpl-%s", common.GetUUID())
+	createdTime := common.GetTimestamp()
+	scanner := bufio.NewScanner(resp.Body)
+	scanner.Split(func(data []byte, atEOF bool) (advance int, token []byte, err error) {
+		if atEOF && len(data) == 0 {
+			return 0, nil, nil
+		}
+		if i := strings.Index(string(data), "\r\n\r\n"); i >= 0 {
+			return i + 4, data[0:i], nil
+		}
+		if atEOF {
+			return len(data), data, nil
+		}
+		return 0, nil, nil
+	})
+	dataChan := make(chan string)
+	stopChan := make(chan bool)
+	go func() {
+		for scanner.Scan() {
+			data := scanner.Text()
+			if !strings.HasPrefix(data, "event: completion") {
+				continue
+			}
+			data = strings.TrimPrefix(data, "event: completion\r\ndata: ")
+			dataChan <- data
+		}
+		stopChan <- true
+	}()
+	common.SetEventStreamHeaders(c)
+	c.Stream(func(w io.Writer) bool {
+		select {
+		case data := <-dataChan:
+			// some implementations may add \r at the end of data
+			data = strings.TrimSuffix(data, "\r")
+			var claudeResponse Response
+			err := json.Unmarshal([]byte(data), &claudeResponse)
+			if err != nil {
+				common.SysError("error unmarshalling stream response: " + err.Error())
+				return true
+			}
+			responseText += claudeResponse.Completion
+			response := streamResponseClaude2OpenAI(&claudeResponse)
+			response.Id = responseId
+			response.Created = createdTime
+			jsonStr, err := json.Marshal(response)
+			if err != nil {
+				common.SysError("error marshalling stream response: " + err.Error())
+				return true
+			}
+			c.Render(-1, common.CustomEvent{Data: "data: " + string(jsonStr)})
+			return true
+		case <-stopChan:
+			c.Render(-1, common.CustomEvent{Data: "data: [DONE]"})
+			return false
+		}
+	})
+	err := resp.Body.Close()
+	if err != nil {
+		return openai.ErrorWrapper(err, "close_response_body_failed", http.StatusInternalServerError), ""
+	}
+	return nil, responseText
+}
+
+func Handler(c *gin.Context, resp *http.Response, promptTokens int, model string) (*openai.ErrorWithStatusCode, *openai.Usage) {
+	responseBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return openai.ErrorWrapper(err, "read_response_body_failed", http.StatusInternalServerError), nil
+	}
+	err = resp.Body.Close()
+	if err != nil {
+		return openai.ErrorWrapper(err, "close_response_body_failed", http.StatusInternalServerError), nil
+	}
+	var claudeResponse Response
+	err = json.Unmarshal(responseBody, &claudeResponse)
+	if err != nil {
+		return openai.ErrorWrapper(err, "unmarshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+	if claudeResponse.Error.Type != "" {
+		return &openai.ErrorWithStatusCode{
+			Error: openai.Error{
+				Message: claudeResponse.Error.Message,
+				Type:    claudeResponse.Error.Type,
+				Param:   "",
+				Code:    claudeResponse.Error.Type,
+			},
+			StatusCode: resp.StatusCode,
+		}, nil
+	}
+	fullTextResponse := responseClaude2OpenAI(&claudeResponse)
+	fullTextResponse.Model = model
+	completionTokens := openai.CountTokenText(claudeResponse.Completion, model)
+	usage := openai.Usage{
+		PromptTokens:     promptTokens,
+		CompletionTokens: completionTokens,
+		TotalTokens:      promptTokens + completionTokens,
+	}
+	fullTextResponse.Usage = usage
+	jsonResponse, err := json.Marshal(fullTextResponse)
+	if err != nil {
+		return openai.ErrorWrapper(err, "marshal_response_body_failed", http.StatusInternalServerError), nil
+	}
+	c.Writer.Header().Set("Content-Type", "application/json")
+	c.Writer.WriteHeader(resp.StatusCode)
+	_, err = c.Writer.Write(jsonResponse)
+	return nil, &usage
+}