FastGPT/src/pages/api/chat/chatGpt.ts
2023-04-17 09:58:22 +08:00

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import type { NextApiRequest, NextApiResponse } from 'next';
import { connectToDatabase } from '@/service/mongo';
import { getOpenAIApi, authChat } from '@/service/utils/chat';
import { httpsAgent, openaiChatFilter } from '@/service/utils/tools';
import { ChatCompletionRequestMessage, ChatCompletionRequestMessageRoleEnum } from 'openai';
import { ChatItemType } from '@/types/chat';
import { jsonRes } from '@/service/response';
import type { ModelSchema } from '@/types/mongoSchema';
import { PassThrough } from 'stream';
import { modelList } from '@/constants/model';
import { pushChatBill } from '@/service/events/pushBill';
import { gpt35StreamResponse } from '@/service/utils/openai';
/* 发送提示词 */
export default async function handler(req: NextApiRequest, res: NextApiResponse) {
let step = 0; // step=1时表示开始了流响应
const stream = new PassThrough();
stream.on('error', () => {
console.log('error: ', 'stream error');
stream.destroy();
});
res.on('close', () => {
stream.destroy();
});
res.on('error', () => {
console.log('error: ', 'request error');
stream.destroy();
});
try {
const { chatId, prompt } = req.body as {
prompt: ChatItemType;
chatId: string;
};
const { authorization } = req.headers;
if (!chatId || !prompt) {
throw new Error('缺少参数');
}
await connectToDatabase();
let startTime = Date.now();
const { chat, userApiKey, systemKey, userId } = await authChat(chatId, authorization);
const model: ModelSchema = chat.modelId;
const modelConstantsData = modelList.find((item) => item.model === model.service.modelName);
if (!modelConstantsData) {
throw new Error('模型加载异常');
}
// 读取对话内容
const prompts = [...chat.content, prompt];
// 如果有系统提示词,自动插入
if (model.systemPrompt) {
prompts.unshift({
obj: 'SYSTEM',
value: model.systemPrompt
});
}
// 控制在 tokens 数量,防止超出
// const filterPrompts = openaiChatFilter(prompts, modelConstantsData.contextMaxToken);
// 格式化文本内容成 chatgpt 格式
const map = {
Human: ChatCompletionRequestMessageRoleEnum.User,
AI: ChatCompletionRequestMessageRoleEnum.Assistant,
SYSTEM: ChatCompletionRequestMessageRoleEnum.System
};
const formatPrompts: ChatCompletionRequestMessage[] = prompts.map((item: ChatItemType) => ({
role: map[item.obj],
content: item.value
}));
// console.log(formatPrompts);
// 计算温度
const temperature = modelConstantsData.maxTemperature * (model.temperature / 10);
// 获取 chatAPI
const chatAPI = getOpenAIApi(userApiKey || systemKey);
// 发出请求
const chatResponse = await chatAPI.createChatCompletion(
{
model: model.service.chatModel,
temperature: temperature,
// max_tokens: modelConstantsData.maxToken,
messages: formatPrompts,
frequency_penalty: 0.5, // 越大,重复内容越少
presence_penalty: -0.5, // 越大,越容易出现新内容
stream: true,
stop: ['.!?。']
},
{
timeout: 40000,
responseType: 'stream',
httpsAgent: httpsAgent(!userApiKey)
}
);
console.log('api response time:', `${(Date.now() - startTime) / 1000}s`);
step = 1;
const { responseContent } = await gpt35StreamResponse({
res,
stream,
chatResponse
});
const promptsContent = formatPrompts.map((item) => item.content).join('');
// 只有使用平台的 key 才计费
pushChatBill({
isPay: !userApiKey,
modelName: model.service.modelName,
userId,
chatId,
text: promptsContent + responseContent
});
} catch (err: any) {
if (step === 1) {
// 直接结束流
console.log('error结束');
stream.destroy();
} else {
res.status(500);
jsonRes(res, {
code: 500,
error: err
});
}
}
}