feat: think tag parse (#3805)

docSite/content/zh-cn/docs/development/upgrading/490.md

@@ -0,0 +1,14 @@
+---
+title: 'V4.9.0(进行中)'
+description: 'FastGPT V4.9.0 更新说明'
+icon: 'upgrade'
+draft: false
+toc: true
+weight: 803
+---
+
+
+## 完整更新内容
+
+1. 新增 - AI 对话节点解析 <think></think> 标签内容，便于各类模型进行思考链输出。
+2. 修复 - 思考链流输出时，有时与正文顺序偏差。

packages/global/core/ai/type.d.ts

@@ -1,14 +1,12 @@
 import openai from 'openai';
 import type {
   ChatCompletionMessageToolCall,
-  ChatCompletionChunk,
   ChatCompletionMessageParam as SdkChatCompletionMessageParam,
   ChatCompletionToolMessageParam,
   ChatCompletionContentPart as SdkChatCompletionContentPart,
   ChatCompletionUserMessageParam as SdkChatCompletionUserMessageParam,
   ChatCompletionToolMessageParam as SdkChatCompletionToolMessageParam,
-  ChatCompletionAssistantMessageParam as SdkChatCompletionAssistantMessageParam,
-  ChatCompletionContentPartText
+  ChatCompletionAssistantMessageParam as SdkChatCompletionAssistantMessageParam
 } from 'openai/resources';
 import { ChatMessageTypeEnum } from './constants';
 import { WorkflowInteractiveResponseType } from '../workflow/template/system/interactive/type';
@@ -71,7 +69,8 @@ export type ChatCompletionMessageFunctionCall =
   };
 
 // Stream response
-export type StreamChatType = Stream<ChatCompletionChunk>;
+export type StreamChatType = Stream<openai.Chat.Completions.ChatCompletionChunk>;
+export type UnStreamChatType = openai.Chat.Completions.ChatCompletion;
 
 export default openai;
 export * from 'openai';

packages/global/core/workflow/runtime/utils.ts

@@ -10,6 +10,7 @@ import { FlowNodeOutputItemType, ReferenceValueType } from '../type/io';
 import { ChatItemType, NodeOutputItemType } from '../../../core/chat/type';
 import { ChatItemValueTypeEnum, ChatRoleEnum } from '../../../core/chat/constants';
 import { replaceVariable, valToStr } from '../../../common/string/tools';
+import { ChatCompletionChunk } from 'openai/resources';
 
 export const getMaxHistoryLimitFromNodes = (nodes: StoreNodeItemType[]): number => {
   let limit = 10;
@@ -419,3 +420,137 @@ export function rewriteNodeOutputByHistories(
     };
   });
 }
+
+// Parse <think></think> tags to think and answer - unstream response
+export const parseReasoningContent = (text: string): [string, string] => {
+  const regex = /<think>([\s\S]*?)<\/think>/;
+  const match = text.match(regex);
+
+  if (!match) {
+    return ['', text];
+  }
+
+  const thinkContent = match[1].trim();
+
+  // Add answer (remaining text after think tag)
+  const answerContent = text.slice(match.index! + match[0].length);
+
+  return [thinkContent, answerContent];
+};
+
+// Parse <think></think> tags to think and answer - stream response
+export const parseReasoningStreamContent = () => {
+  let isInThinkTag: boolean | undefined;
+
+  const startTag = '<think>';
+  let startTagBuffer = '';
+
+  const endTag = '</think>';
+  let endTagBuffer = '';
+
+  /* 
+    parseReasoning - 只控制是否主动解析 <think></think>，如果接口已经解析了，仍然会返回 think 内容。
+  */
+  const parsePart = (
+    part: {
+      choices: {
+        delta: {
+          content?: string;
+          reasoning_content?: string;
+        };
+      }[];
+    },
+    parseReasoning = false
+  ): [string, string] => {
+    const content = part.choices?.[0]?.delta?.content || '';
+
+    // @ts-ignore
+    const reasoningContent = part.choices?.[0]?.delta?.reasoning_content || '';
+    if (reasoningContent || !parseReasoning) {
+      isInThinkTag = false;
+      return [reasoningContent, content];
+    }
+
+    if (!content) {
+      return ['', ''];
+    }
+
+    // 如果不在 think 标签中，或者有 reasoningContent(接口已解析），则返回 reasoningContent 和 content
+    if (isInThinkTag === false) {
+      return ['', content];
+    }
+
+    // 检测是否为 think 标签开头的数据
+    if (isInThinkTag === undefined) {
+      // Parse content think and answer
+      startTagBuffer += content;
+      // 太少内容时候，暂时不解析
+      if (startTagBuffer.length < startTag.length) {
+        return ['', ''];
+      }
+
+      if (startTagBuffer.startsWith(startTag)) {
+        isInThinkTag = true;
+        return [startTagBuffer.slice(startTag.length), ''];
+      }
+
+      // 如果未命中 think 标签，则认为不在 think 标签中，返回 buffer 内容作为 content
+      isInThinkTag = false;
+      return ['', startTagBuffer];
+    }
+
+    // 确认是 think 标签内容，开始返回 think 内容，并实时检测 </think>
+    /* 
+      检测 </think> 方案。
+      存储所有疑似 </think> 的内容，直到检测到完整的 </think> 标签或超出 </think> 长度。
+      content 返回值包含以下几种情况:
+        abc - 完全未命中尾标签
+        abc<th - 命中一部分尾标签
+        abc</think> - 完全命中尾标签
+        abc</think>abc - 完全命中尾标签
+        </think>abc - 完全命中尾标签
+        k>abc - 命中一部分尾标签
+    */
+    // endTagBuffer 专门用来记录疑似尾标签的内容
+    if (endTagBuffer) {
+      endTagBuffer += content;
+      if (endTagBuffer.includes(endTag)) {
+        isInThinkTag = false;
+        const answer = endTagBuffer.slice(endTag.length);
+        return ['', answer];
+      } else if (endTagBuffer.length >= endTag.length) {
+        // 缓存内容超出尾标签长度，且仍未命中 </think>，则认为本次猜测 </think> 失败，仍处于 think 阶段。
+        const tmp = endTagBuffer;
+        endTagBuffer = '';
+        return [tmp, ''];
+      }
+      return ['', ''];
+    } else if (content.includes(endTag)) {
+      // 返回内容，完整命中</think>，直接结束
+      isInThinkTag = false;
+      const [think, answer] = content.split(endTag);
+      return [think, answer];
+    } else {
+      // 无 buffer，且未命中 </think>，开始疑似 </think> 检测。
+      for (let i = 1; i < endTag.length; i++) {
+        const partialEndTag = endTag.slice(0, i);
+        // 命中一部分尾标签
+        if (content.endsWith(partialEndTag)) {
+          const think = content.slice(0, -partialEndTag.length);
+          endTagBuffer += partialEndTag;
+          return [think, ''];
+        }
+      }
+    }
+
+    // 完全未命中尾标签，还是 think 阶段。
+    return [content, ''];
+  };
+
+  const getStartTagBuffer = () => startTagBuffer;
+
+  return {
+    parsePart,
+    getStartTagBuffer
+  };
+};

packages/service/core/ai/config.ts

@@ -1,7 +1,9 @@
 import OpenAI from '@fastgpt/global/core/ai';
 import {
   ChatCompletionCreateParamsNonStreaming,
-  ChatCompletionCreateParamsStreaming
+  ChatCompletionCreateParamsStreaming,
+  StreamChatType,
+  UnStreamChatType
 } from '@fastgpt/global/core/ai/type';
 import { getErrText } from '@fastgpt/global/common/error/utils';
 import { addLog } from '../../common/system/log';
@@ -38,29 +40,30 @@ export const getAxiosConfig = (props?: { userKey?: OpenaiAccountType }) => {
   };
 };
 
-type CompletionsBodyType =
-  | ChatCompletionCreateParamsNonStreaming
-  | ChatCompletionCreateParamsStreaming;
-type InferResponseType<T extends CompletionsBodyType> =
-  T extends ChatCompletionCreateParamsStreaming
-    ? OpenAI.Chat.Completions.ChatCompletionChunk
-    : OpenAI.Chat.Completions.ChatCompletion;
-
-export const createChatCompletion = async <T extends CompletionsBodyType>({
+export const createChatCompletion = async ({
   body,
   userKey,
   timeout,
   options
 }: {
-  body: T;
+  body: ChatCompletionCreateParamsNonStreaming | ChatCompletionCreateParamsStreaming;
   userKey?: OpenaiAccountType;
   timeout?: number;
   options?: OpenAI.RequestOptions;
-}): Promise<{
-  response: InferResponseType<T>;
-  isStreamResponse: boolean;
-  getEmptyResponseTip: () => string;
-}> => {
+}): Promise<
+  {
+    getEmptyResponseTip: () => string;
+  } & (
+    | {
+        response: StreamChatType;
+        isStreamResponse: true;
+      }
+    | {
+        response: UnStreamChatType;
+        isStreamResponse: false;
+      }
+  )
+> => {
   try {
     const modelConstantsData = getLLMModel(body.model);
 
@@ -96,9 +99,17 @@ export const createChatCompletion = async <T extends CompletionsBodyType>({
       return i18nT('chat:LLM_model_response_empty');
     };
 
+    if (isStreamResponse) {
+      return {
+        response,
+        isStreamResponse: true,
+        getEmptyResponseTip
+      };
+    }
+
     return {
-      response: response as InferResponseType<T>,
-      isStreamResponse,
+      response,
+      isStreamResponse: false,
       getEmptyResponseTip
     };
   } catch (error) {