perf: 减少聊天内容配置，自动截断上下文

src/service/utils/chat.ts

@@ -32,14 +32,11 @@ export const authChat = async (chatId: string, authorization?: string) => {
     return Promise.reject('模型不存在');
   }
 
-  // 安全校验
-  if (chat.loadAmount === 0 || chat.expiredTime <= Date.now()) {
-    return Promise.reject('聊天框已过期');
-  }
-
-  // 分享校验
+  // 凭证校验
   if (!chat.isShare) {
     await authToken(authorization);
+  } else if (chat.loadAmount === 0 || chat.expiredTime <= Date.now()) {
+    return Promise.reject('聊天框已过期');
   }
 
   // 获取 user 的 apiKey
@@ -47,6 +44,7 @@ export const authChat = async (chatId: string, authorization?: string) => {
 
   const userApiKey = user.accounts?.find((item: any) => item.type === 'openai')?.value;
 
+  // 没有 apikey ，校验余额
   if (!userApiKey && formatPrice(user.balance) <= 0) {
     return Promise.reject('该账号余额不足');
   }

src/service/utils/tools.ts

@@ -4,6 +4,8 @@ import { User } from '../models/user';
 import tunnel from 'tunnel';
 import type { UserModelSchema } from '@/types/mongoSchema';
 import { formatPrice } from '@/utils/user';
+import { ChatItemType } from '@/types/chat';
+import { encode } from 'gpt-token-utils';
 
 /* 密码加密 */
 export const hashPassword = (psw: string) => {
@@ -91,3 +93,29 @@ export const httpsAgent =
         }
       })
     : undefined;
+
+/* tokens 截断 */
+export const openaiChatFilter = (prompts: ChatItemType[], maxTokens: number) => {
+  let res: ChatItemType[] = [];
+
+  let systemPrompt: ChatItemType | null = null;
+
+  //  System 词保留
+  if (prompts[0]?.obj === 'SYSTEM') {
+    systemPrompt = prompts.shift() as ChatItemType;
+    maxTokens -= encode(prompts[0].value).length;
+  }
+
+  // 从后往前截取
+  for (let i = prompts.length - 1; i >= 0; i--) {
+    const tokens = encode(prompts[i].value).length;
+    if (maxTokens >= tokens) {
+      res.unshift(prompts[i]);
+      maxTokens -= tokens;
+    } else {
+      break;
+    }
+  }
+
+  return systemPrompt ? [systemPrompt, ...res] : res;
+};