From 75252fded6321141674d148c05b4779c6c7c9bc5 Mon Sep 17 00:00:00 2001
From: Cursor Agent <cursoragent@cursor.com>
Date: Sat, 5 Jul 2025 23:56:51 +0000
Subject: [PATCH] Refactor proxy middleware for improved SSE and API request
 handling

Co-authored-by: jxxghp <jxxghp@163.com>
---
 SSE_修复报告.md   | 141 +++++++++++++++++++++++++++++++++
 package.json      |   1 +
 public/service.js | 196 +++++++++++++++++++++++++++++++---------------
 yarn.lock         |  62 +++++++++++++--
 4 files changed, 330 insertions(+), 70 deletions(-)
 create mode 100644 SSE_修复报告.md

diff --git a/SSE_修复报告.md b/SSE_修复报告.md
new file mode 100644
index 00000000..56a328a8
--- /dev/null
+++ b/SSE_修复报告.md
@@ -0,0 +1,141 @@
+# SSE (Server-Sent Events) 问题分析和修复报告
+
+## 问题描述
+
+用户反映使用新的 `public/service.js` 文件后，SSE (Server-Sent Events) 不能正常工作。
+
+## 问题分析
+
+通过对项目代码和最新SSE文档的研究，发现了以下问题：
+
+### 1. 原始代码问题
+
+原始的 `express-http-proxy` 配置在处理SSE流式传输时存在以下问题：
+
+- `userResDecorator` 中的SSE处理逻辑虽然返回了 `false`，但实际的流式传输机制不够完善
+- 缺乏正确的流管道设置
+- 错误处理不够健壮
+- 缺少专门的SSE代理中间件
+
+### 2. SSE的技术要求
+
+根据最新的SSE最佳实践，正确的SSE代理需要：
+
+- 设置正确的HTTP头部：`Content-Type: text/event-stream`
+- 保持持久连接：`Connection: keep-alive`
+- 禁用缓存：`Cache-Control: no-cache`
+- 正确处理流式传输，避免缓冲
+- 优雅处理客户端断开连接
+
+## 修复方案
+
+### 主要改进
+
+1. **引入专门的SSE代理中间件**
+   - 使用 `http-proxy-middleware` 包提供专门的SSE支持
+   - 分离SSE请求和普通API请求的处理逻辑
+
+2. **改进的流式传输处理**
+   ```javascript
+   // 直接将代理响应流式传输到客户端
+   proxyRes.pipe(res);
+   ```
+
+3. **更好的连接管理**
+   - 正确处理客户端断开连接
+   - 优雅的错误处理
+   - 资源清理
+
+4. **双重代理架构**
+   - SSE请求使用专门的 `createProxyMiddleware`
+   - 普通API请求继续使用 `express-http-proxy`
+
+### 依赖更新
+
+添加了新的依赖：
+```json
+"http-proxy-middleware": "^3.0.0"
+```
+
+### 核心修改
+
+1. **SSE检测和路由**
+   ```javascript
+   app.use('/api', (req, res, next) => {
+     // 检测是否为SSE请求
+     const isSSE = req.headers.accept && req.headers.accept.includes('text/event-stream');
+     
+     if (isSSE) {
+       // 使用专门的SSE代理中间件
+       sseProxyMiddleware(req, res, next);
+     } else {
+       // 使用普通API代理中间件
+       apiProxyMiddleware(req, res, next);
+     }
+   });
+   ```
+
+2. **专门的SSE代理中间件**
+   ```javascript
+   const sseProxyMiddleware = createProxyMiddleware({
+     target: `http://${proxyConfig.URL}:${proxyConfig.PORT}`,
+     changeOrigin: true,
+     timeout: 0, // 无超时
+     onProxyRes: (proxyRes, req, res) => {
+       const isSSE = proxyRes.headers['content-type'] && 
+                     proxyRes.headers['content-type'].includes('text/event-stream');
+       
+       if (isSSE) {
+         // 设置正确的SSE响应头
+         res.writeHead(proxyRes.statusCode, {
+           'Content-Type': 'text/event-stream',
+           'Cache-Control': 'no-cache',
+           'Connection': 'keep-alive',
+           'Access-Control-Allow-Origin': '*',
+           'Access-Control-Allow-Headers': 'Cache-Control, Content-Type, Authorization'
+         });
+         
+         // 直接流式传输
+         proxyRes.pipe(res);
+       }
+     }
+   });
+   ```
+
+## 实施步骤
+
+1. ✅ 更新 `package.json` 添加 `http-proxy-middleware` 依赖
+2. ✅ 运行 `yarn install` 安装新依赖
+3. ✅ 修改 `public/service.js` 实现新的SSE处理逻辑
+4. 🔄 测试SSE功能确保正常工作
+
+## 受影响的功能
+
+项目中使用SSE的功能包括：
+- 系统进度监控 (`/api/system/progress/*`)
+- 日志查看 (`LoggingView.vue`)
+- 消息通知 (`MessageView.vue`, `UserNotification.vue`)
+- 文件传输进度 (`TransferQueueDialog.vue`, `ReorganizeDialog.vue`)
+- 批量重命名进度 (`FileList.vue`)
+
+## 验证方法
+
+可以通过以下方式验证修复效果：
+
+1. 检查浏览器开发者工具中的Network面板
+2. 确认SSE请求显示为 `text/event-stream` 类型
+3. 验证数据是否实时流式传输
+4. 测试客户端断开连接后的清理工作
+
+## 技术参考
+
+本修复方案基于以下最新文档和最佳实践：
+
+- [Server-Sent Events: A Practical Guide for the Real World](https://tigerabrodi.blog/server-sent-events-a-practical-guide-for-the-real-world)
+- [Building an SSE Proxy: Streaming and Forwarding Server-Sent Events](https://medium.com/@sercan.celenk/building-an-sse-proxy-in-go-streaming-and-forwarding-server-sent-events-1c951d3acd70)
+- [How to Proxy and Modify OpenAI Stream Responses](https://medium.com/@TechTim42/how-to-proxy-and-modify-openai-stream-responses-for-enhanced-user-experience-82cb9ed29b46)
+- [express-http-proxy SSE 最佳实践](https://tigerabrodi.blog/server-sent-events-a-practical-guide-for-the-real-world)
+
+## 结论
+
+通过引入专门的SSE代理中间件和改进的流式传输处理，应该能够解决用户反映的SSE不能正常工作的问题。新的架构更加符合SSE的技术要求，提供了更好的错误处理和连接管理。
\ No newline at end of file
diff --git a/package.json b/package.json
index 4a591383..ee40bc8a 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
     "dayjs": "^1.11.13",
     "express": "^4.21.2",
     "express-http-proxy": "^2.1.1",
+    "http-proxy-middleware": "^3.0.0",
     "js-cookie": "^3.0.5",
     "lodash-es": "^4.17.21",
     "mousetrap": "^1.6.5",
diff --git a/public/service.js b/public/service.js
index e5ce288c..420af091 100644
--- a/public/service.js
+++ b/public/service.js
@@ -1,6 +1,7 @@
 const path = require('node:path')
 const express = require('express')
 const proxy = require('express-http-proxy')
+const { createProxyMiddleware } = require('http-proxy-middleware')
 
 const app = express()
 const port = process.env.NGINX_PORT || 3000
@@ -14,76 +15,141 @@ const proxyConfig = {
 // 静态文件服务目录
 app.use(express.static(__dirname))
 
-// 配置代理中间件将请求转发给后端API
-app.use(
-  '/api',
-  proxy(`${proxyConfig.URL}:${proxyConfig.PORT}`, {
-    // 路径加上 /api 前缀
-    proxyReqPathResolver: (req) => {
-      return `/api${req.url}`
-    },
-    proxyReqOptDecorator: (proxyReqOpts, srcReq) => {
-      proxyReqOpts.headers = proxyReqOpts.headers || {};
+// 创建专门的SSE代理中间件
+const sseProxyMiddleware = createProxyMiddleware({
+  target: `http://${proxyConfig.URL}:${proxyConfig.PORT}`,
+  changeOrigin: true,
+  ws: false,
+  timeout: 0, // 无超时
+  proxyTimeout: 0, // 无超时
+  headers: {
+    'Connection': 'keep-alive',
+    'Cache-Control': 'no-cache'
+  },
+  onProxyRes: (proxyRes, req, res) => {
+    // 检测SSE响应
+    const isSSE = proxyRes.headers['content-type'] && 
+                  proxyRes.headers['content-type'].includes('text/event-stream');
+    
+    if (isSSE) {
+      // 设置SSE响应头
+      res.writeHead(proxyRes.statusCode, {
+        'Content-Type': 'text/event-stream',
+        'Cache-Control': 'no-cache',
+        'Connection': 'keep-alive',
+        'Access-Control-Allow-Origin': '*',
+        'Access-Control-Allow-Headers': 'Cache-Control, Content-Type, Authorization'
+      });
       
-      // 检测是否为SSE请求
-      const isSSE = srcReq.headers.accept && srcReq.headers.accept.includes('text/event-stream');
+      // 直接将代理响应流式传输到客户端
+      proxyRes.pipe(res);
       
-      // 动态设置超时时间：SSE无超时，普通请求600秒超时
-      proxyReqOpts.timeout = isSSE ? 0 : 600000;
-      
-      if (isSSE) {
-        // SSE请求的特殊头部设置
-        proxyReqOpts.headers['Cache-Control'] = 'no-cache';
-        proxyReqOpts.headers['Connection'] = 'keep-alive';
-        proxyReqOpts.headers['Accept'] = 'text/event-stream';
-      }
-      
-      return proxyReqOpts;
-    },
-    userResDecorator: (proxyRes, proxyResData, userReq, userRes) => {
-      // 检测响应是否为SSE类型
-      const isSSEResponse = proxyRes.headers['content-type'] && 
-                           proxyRes.headers['content-type'].includes('text/event-stream');
-      
-      if (isSSEResponse) {
-        // SSE响应：设置流式传输头部并禁用缓冲
-        userRes.writeHead(proxyRes.statusCode, {
-          'Content-Type': 'text/event-stream',
-          'Cache-Control': 'no-cache',
-          'Connection': 'keep-alive',
-          'Access-Control-Allow-Origin': '*',
-          'Access-Control-Allow-Headers': 'Cache-Control'
-        });
-        return false; // 禁用默认响应处理，让数据直接流向客户端
-      } else {
-        // 普通响应：正常处理
-        return proxyResData;
-      }
-    },
-    // 统一错误处理（添加超时错误处理）
-    proxyErrorHandler: (err, res, next) => {
-      // 客户端断开连接的正常情况（常见于SSE）
-      if (err.code === 'ECONNRESET' || err.code === 'EPIPE') {
-        console.log('Client disconnected:', err.code);
-        res.end(); // 优雅结束响应
-        return;
-      }
-      
-      // 添加超时错误处理
-      if (err.code === 'ETIMEDOUT') {
-        console.log('Proxy request timed out:', err.code);
-        if (!res.headersSent) {
-          res.status(504).send('Gateway Timeout');
+      // 处理客户端断开连接
+      req.on('close', () => {
+        console.log('Client disconnected from SSE stream');
+        if (proxyRes.destroy) {
+          proxyRes.destroy();
         }
-        return;
-      }
+      });
       
-      // 其他错误正常处理
-      console.error('Proxy error:', err);
-      next(err);
+      // 处理代理响应结束
+      proxyRes.on('end', () => {
+        console.log('SSE stream ended');
+        if (!res.headersSent) {
+          res.end();
+        }
+      });
+      
+      // 处理代理响应错误
+      proxyRes.on('error', (err) => {
+        console.error('SSE proxy response error:', err);
+        if (!res.headersSent) {
+          res.status(500).end();
+        }
+      });
     }
-  })
-);
+  },
+  onError: (err, req, res) => {
+    console.error('SSE proxy error:', err);
+    if (!res.headersSent) {
+      res.status(500).json({ error: 'Proxy error' });
+    }
+  }
+});
+
+// 创建普通API代理中间件
+const apiProxyMiddleware = proxy(`${proxyConfig.URL}:${proxyConfig.PORT}`, {
+  // 路径加上 /api 前缀
+  proxyReqPathResolver: (req) => {
+    return `/api${req.url}`
+  },
+  proxyReqOptDecorator: (proxyReqOpts, srcReq) => {
+    proxyReqOpts.headers = proxyReqOpts.headers || {};
+    
+    // 检测是否为SSE请求
+    const isSSE = srcReq.headers.accept && srcReq.headers.accept.includes('text/event-stream');
+    
+    if (!isSSE) {
+      // 普通请求设置超时
+      proxyReqOpts.timeout = 600000; // 600秒超时
+    }
+    
+    return proxyReqOpts;
+  },
+  userResDecorator: (proxyRes, proxyResData, userReq, userRes) => {
+    // 只处理非SSE响应
+    const isSSEResponse = proxyRes.headers['content-type'] && 
+                         proxyRes.headers['content-type'].includes('text/event-stream');
+    
+    if (!isSSEResponse) {
+      // 普通响应：正常处理
+      return proxyResData;
+    }
+    
+    // SSE响应不在这里处理，已经由专门的中间件处理
+    return proxyResData;
+  },
+  // 错误处理
+  proxyErrorHandler: (err, res, next) => {
+    // 客户端断开连接的正常情况
+    if (err.code === 'ECONNRESET' || err.code === 'EPIPE') {
+      console.log('Client disconnected:', err.code);
+      if (!res.headersSent) {
+        res.end();
+      }
+      return;
+    }
+    
+    // 超时错误处理
+    if (err.code === 'ETIMEDOUT') {
+      console.log('Proxy request timed out:', err.code);
+      if (!res.headersSent) {
+        res.status(504).send('Gateway Timeout');
+      }
+      return;
+    }
+    
+    // 其他错误
+    console.error('Proxy error:', err);
+    if (!res.headersSent) {
+      res.status(500).send('Internal Server Error');
+    }
+  }
+});
+
+// 配置API代理路由
+app.use('/api', (req, res, next) => {
+  // 检测是否为SSE请求
+  const isSSE = req.headers.accept && req.headers.accept.includes('text/event-stream');
+  
+  if (isSSE) {
+    // 使用专门的SSE代理中间件
+    sseProxyMiddleware(req, res, next);
+  } else {
+    // 使用普通API代理中间件
+    apiProxyMiddleware(req, res, next);
+  }
+});
 
 // 配置代理中间件将CookieCloud请求转发给后端API
 app.use(
diff --git a/yarn.lock b/yarn.lock
index f3d35833..1c4e09bf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1858,6 +1858,13 @@
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-1.0.7.tgz#4158d3105276773d5b7695cd4834b1722e4f37a8"
   integrity sha512-w28IoSUCJpidD/TGviZwwMJckNESJZXFu7NBZ5YJ4mEUnNraUn9Pm8HSZm/jDF1pDWYKspWE7oVphigUPRakIQ==
 
+"@types/http-proxy@^1.17.15":
+  version "1.17.16"
+  resolved "https://registry.yarnpkg.com/@types/http-proxy/-/http-proxy-1.17.16.tgz#dee360707b35b3cc85afcde89ffeebff7d7f9240"
+  integrity sha512-sdWoUajOB1cd0A8cRRQ1cfyWNbmFKLAqBB89Y8x5iYyG/mkJHc0YUH8pdWBy2omi9qtCpiIgGjuwO0dQST2l5w==
+  dependencies:
+    "@types/node" "*"
+
 "@types/js-cookie@^3.0.6":
   version "3.0.6"
   resolved "https://registry.yarnpkg.com/@types/js-cookie/-/js-cookie-3.0.6.tgz#a04ca19e877687bd449f5ad37d33b104b71fdf95"
@@ -4019,6 +4026,11 @@ event-target-shim@^5.0.0:
   resolved "https://registry.yarnpkg.com/event-target-shim/-/event-target-shim-5.0.1.tgz#5d4d3ebdf9583d63a5333ce2deb7480ab2b05789"
   integrity sha512-i/2XbnSz/uxRCU6+NdVJgKWDTM427+MqYbkQzD321DuCQJUqOuJKIA0IM2+W2xtYHdKOmZ4dR6fExsd4SXL+WQ==
 
+eventemitter3@^4.0.0:
+  version "4.0.7"
+  resolved "https://registry.yarnpkg.com/eventemitter3/-/eventemitter3-4.0.7.tgz#2de9b68f6528d5644ef5c59526a1b4a07306169f"
+  integrity sha512-8guHBZCwKnFhYdHr2ysuRWErTwhoN2X8XELRlrRwpmfeY2jjuUN4taQMsULKUVo1K4DvZl+0pgfyoysHxvmvEw==
+
 events@^3.3.0:
   version "3.3.0"
   resolved "https://registry.yarnpkg.com/events/-/events-3.3.0.tgz#31a95ad0a924e2d2c419a813aeb2c4e878ea7400"
@@ -4237,7 +4249,7 @@ flatted@^3.2.9, flatted@^3.3.3:
   resolved "https://registry.yarnpkg.com/flatted/-/flatted-3.3.3.tgz#67c8fad95454a7c7abebf74bb78ee74a44023358"
   integrity sha512-GX+ysw4PBCz0PzosHDepZGANEuFCMLrnRTiEy9McGjmkCQYwRq4A/X786G/fjM/+OjsWSU1ZrY5qyARZmO/uwg==
 
-follow-redirects@^1.15.6:
+follow-redirects@^1.0.0, follow-redirects@^1.15.6:
   version "1.15.9"
   resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.9.tgz#a604fa10e443bf98ca94228d9eebcc2e8a2c8ee1"
   integrity sha512-gew4GsXizNgdoRyqmyfMHyAmXsZDk6mHkSxZFCzW9gwlbtOW44CDtYavM+y+72qD/Vq2l550kMF52DT8fOLJqQ==
@@ -4620,6 +4632,27 @@ http-errors@2.0.0:
     statuses "2.0.1"
     toidentifier "1.0.1"
 
+http-proxy-middleware@^3.0.0:
+  version "3.0.5"
+  resolved "https://registry.yarnpkg.com/http-proxy-middleware/-/http-proxy-middleware-3.0.5.tgz#9dcde663edc44079bc5a9c63e03fe5e5d6037fab"
+  integrity sha512-GLZZm1X38BPY4lkXA01jhwxvDoOkkXqjgVyUzVxiEK4iuRu03PZoYHhHRwxnfhQMDuaxi3vVri0YgSro/1oWqg==
+  dependencies:
+    "@types/http-proxy" "^1.17.15"
+    debug "^4.3.6"
+    http-proxy "^1.18.1"
+    is-glob "^4.0.3"
+    is-plain-object "^5.0.0"
+    micromatch "^4.0.8"
+
+http-proxy@^1.18.1:
+  version "1.18.1"
+  resolved "https://registry.yarnpkg.com/http-proxy/-/http-proxy-1.18.1.tgz#401541f0534884bbf95260334e72f88ee3976549"
+  integrity sha512-7mz/721AbnJwIVbnaSv1Cz3Am0ZLT/UBwkC92VlxhXv/k/BBQfM2fXElQNC27BVGr0uwUpplYPQM9LnaBMR5NQ==
+  dependencies:
+    eventemitter3 "^4.0.0"
+    follow-redirects "^1.0.0"
+    requires-port "^1.0.0"
+
 iconv-lite@0.4.24:
   version "0.4.24"
   resolved "https://registry.yarnpkg.com/iconv-lite/-/iconv-lite-0.4.24.tgz#2022b4b25fbddc21d2f524974a474aafe733908b"
@@ -6284,6 +6317,11 @@ require-from-string@^2.0.2:
   resolved "https://registry.yarnpkg.com/require-from-string/-/require-from-string-2.0.2.tgz#89a7fdd938261267318eafe14f9c32e598c36909"
   integrity sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==
 
+requires-port@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/requires-port/-/requires-port-1.0.0.tgz#925d2601d39ac485e091cf0da5c6e694dc3dcaff"
+  integrity sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==
+
 resize-observer-polyfill@^1.5.1:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/resize-observer-polyfill/-/resize-observer-polyfill-1.5.1.tgz#0e9020dd3d21024458d4ebd27e23e40269810464"
@@ -6718,8 +6756,16 @@ std-env@^3.9.0:
   resolved "https://registry.yarnpkg.com/std-env/-/std-env-3.9.0.tgz#1a6f7243b339dca4c9fd55e1c7504c77ef23e8f1"
   integrity sha512-UGvjygr6F6tpH7o2qyqR6QYpwraIjKSdtzyBdyytFOHmPZY917kwdwLG0RbOjWOnKmnm3PeHjaoLLMie7kPLQw==
 
-"string-width-cjs@npm:string-width@^4.2.0", string-width@^4.1.0, string-width@^4.2.3:
-  name string-width-cjs
+"string-width-cjs@npm:string-width@^4.2.0":
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-4.2.3.tgz#269c7117d27b05ad2e536830a8ec895ef9c6d010"
+  integrity sha512-wKyQRQpjJ0sIp62ErSZdGsjMJWsap5oRNihHhu6G7JVO/9jIB6UyevL+tXuOqrng8j/cxKTWyWUwvSTriiZz/g==
+  dependencies:
+    emoji-regex "^8.0.0"
+    is-fullwidth-code-point "^3.0.0"
+    strip-ansi "^6.0.1"
+
+string-width@^4.1.0, string-width@^4.2.3:
   version "4.2.3"
   resolved "https://registry.yarnpkg.com/string-width/-/string-width-4.2.3.tgz#269c7117d27b05ad2e536830a8ec895ef9c6d010"
   integrity sha512-wKyQRQpjJ0sIp62ErSZdGsjMJWsap5oRNihHhu6G7JVO/9jIB6UyevL+tXuOqrng8j/cxKTWyWUwvSTriiZz/g==
@@ -6804,8 +6850,14 @@ stringify-object@^3.3.0:
     is-obj "^1.0.1"
     is-regexp "^1.0.0"
 
-"strip-ansi-cjs@npm:strip-ansi@^6.0.1", strip-ansi@^6.0.0, strip-ansi@^6.0.1:
-  name strip-ansi-cjs
+"strip-ansi-cjs@npm:strip-ansi@^6.0.1":
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-6.0.1.tgz#9e26c63d30f53443e9489495b2105d37b67a85d9"
+  integrity sha512-Y38VPSHcqkFrCpFnQ9vuSXmquuv5oXOKpGeT6aGrr3o3Gc9AlVa6JBfUSOCnbxGGZF+/0ooI7KrPuUSztUdU5A==
+  dependencies:
+    ansi-regex "^5.0.1"
+
+strip-ansi@^6.0.0, strip-ansi@^6.0.1:
   version "6.0.1"
   resolved "https://registry.yarnpkg.com/strip-ansi/-/strip-ansi-6.0.1.tgz#9e26c63d30f53443e9489495b2105d37b67a85d9"
   integrity sha512-Y38VPSHcqkFrCpFnQ9vuSXmquuv5oXOKpGeT6aGrr3o3Gc9AlVa6JBfUSOCnbxGGZF+/0ooI7KrPuUSztUdU5A==