perf: model framwork

src/pages/api/chat/chat.ts

@@ -0,0 +1,180 @@
+import type { NextApiRequest, NextApiResponse } from 'next';
+import { connectToDatabase } from '@/service/mongo';
+import { getOpenAIApi, authChat } from '@/service/utils/auth';
+import { axiosConfig, openaiChatFilter, systemPromptFilter } from '@/service/utils/tools';
+import { ChatItemType } from '@/types/chat';
+import { jsonRes } from '@/service/response';
+import { PassThrough } from 'stream';
+import { modelList, ModelVectorSearchModeMap, ModelVectorSearchModeEnum } from '@/constants/model';
+import { pushChatBill } from '@/service/events/pushBill';
+import { gpt35StreamResponse } from '@/service/utils/openai';
+import { searchKb_openai } from '@/service/tools/searchKb';
+
+/* 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, modelId } = req.body as {
+      prompt: ChatItemType;
+      modelId: string;
+      chatId: '' | string;
+    };
+
+    const { authorization } = req.headers;
+    if (!modelId || !prompt) {
+      throw new Error('缺少参数');
+    }
+
+    await connectToDatabase();
+    let startTime = Date.now();
+
+    const { model, content, userApiKey, systemKey, userId } = await authChat({
+      modelId,
+      chatId,
+      authorization
+    });
+
+    const modelConstantsData = modelList.find((item) => item.chatModel === model.chat.chatModel);
+    if (!modelConstantsData) {
+      throw new Error('模型加载异常');
+    }
+
+    // 读取对话内容
+    const prompts = [...content, prompt];
+
+    // 使用了知识库搜索
+    if (model.chat.useKb) {
+      const { systemPrompts } = await searchKb_openai({
+        apiKey: userApiKey || systemKey,
+        isPay: !userApiKey,
+        text: prompt.value,
+        similarity: ModelVectorSearchModeMap[model.chat.searchMode]?.similarity || 0.22,
+        modelId,
+        userId
+      });
+
+      // filter system prompt
+      if (
+        systemPrompts.length === 0 &&
+        model.chat.searchMode === ModelVectorSearchModeEnum.hightSimilarity
+      ) {
+        return res.send('对不起，你的问题不在知识库中。');
+      }
+      /* 高相似度+无上下文，不添加额外知识,仅用系统提示词 */
+      if (
+        systemPrompts.length === 0 &&
+        model.chat.searchMode === ModelVectorSearchModeEnum.noContext
+      ) {
+        prompts.unshift({
+          obj: 'SYSTEM',
+          value: model.chat.systemPrompt
+        });
+      } else {
+        // 有匹配情况下，system 添加知识库内容。
+        // 系统提示词过滤，最多 2500 tokens
+        const filterSystemPrompt = systemPromptFilter({
+          model: model.chat.chatModel,
+          prompts: systemPrompts,
+          maxTokens: 2500
+        });
+
+        prompts.unshift({
+          obj: 'SYSTEM',
+          value: `
+  ${model.chat.systemPrompt}
+  ${
+    model.chat.searchMode === ModelVectorSearchModeEnum.hightSimilarity
+      ? `不回答知识库外的内容.`
+      : ''
+  }
+  知识库内容为: ${filterSystemPrompt}'
+  `
+        });
+      }
+    } else {
+      // 没有用知识库搜索，仅用系统提示词
+      if (model.chat.systemPrompt) {
+        prompts.unshift({
+          obj: 'SYSTEM',
+          value: model.chat.systemPrompt
+        });
+      }
+    }
+
+    // 控制总 tokens 数量，防止超出
+    const filterPrompts = openaiChatFilter({
+      model: model.chat.chatModel,
+      prompts,
+      maxTokens: modelConstantsData.contextMaxToken - 500
+    });
+
+    // 计算温度
+    const temperature = (modelConstantsData.maxTemperature * (model.chat.temperature / 10)).toFixed(
+      2
+    );
+    // console.log(filterPrompts);
+    // 获取 chatAPI
+    const chatAPI = getOpenAIApi(userApiKey || systemKey);
+    // 发出请求
+    const chatResponse = await chatAPI.createChatCompletion(
+      {
+        model: model.chat.chatModel,
+        temperature: Number(temperature) || 0,
+        messages: filterPrompts,
+        frequency_penalty: 0.5, // 越大，重复内容越少
+        presence_penalty: -0.5, // 越大，越容易出现新内容
+        stream: true,
+        stop: ['.!?。']
+      },
+      {
+        timeout: 40000,
+        responseType: 'stream',
+        ...axiosConfig()
+      }
+    );
+
+    console.log('api response time:', `${(Date.now() - startTime) / 1000}s`);
+
+    step = 1;
+
+    const { responseContent } = await gpt35StreamResponse({
+      res,
+      stream,
+      chatResponse
+    });
+
+    // 只有使用平台的 key 才计费
+    pushChatBill({
+      isPay: !userApiKey,
+      chatModel: model.chat.chatModel,
+      userId,
+      chatId,
+      messages: filterPrompts.concat({ role: 'assistant', content: 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
+      });
+    }
+  }
+}