准备完成通讯模块

frontend/Web/index.js

@@ -6,20 +6,150 @@ const { Server } = require('socket.io');
 const app = express();
 const server = createServer(app);
 const io = new Server(server);
+class Queue {
+  constructor() {
+    this.items = [];
+  }
 
+  // 添加元素到队列的尾部
+  enqueue(element) {
+    this.items.push(element);
+  }
+
+  // 从队列的头部移除元素并返回移除的元素
+  dequeue() {
+    if (this.isEmpty()) {
+      return null;
+    }
+    return this.items.shift();
+  }
+
+  // 返回队列的头部元素
+  front() {
+    if (this.isEmpty()) {
+      return null;
+    }
+    return this.items[0];
+  }
+
+  // 检查队列是否为空
+  isEmpty() {
+    return this.items.length === 0;
+  }
+
+  // 返回队列的大小
+  size() {
+    return this.items.length;
+  }
+
+  // 清空队列
+  clear() {
+    this.items = [];
+  }
+}
+
+function sleep(ms) {
+  return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+const message_map=new Map();
+const { spawn } = require('child_process');
+const backend=spawn('/workspaces/BH-Bookstore-2023/build/code',['-s','-c','/tmp/conf/']);
+
+const AsyncLock = require('async-lock');
+const lock = new AsyncLock();
+
+function SendRequest(data) {
+  console.log("SendRequest called");
+  return new Promise((resolve, reject) => {
+    lock.acquire('myLock', (done) => {
+      console.log("SendRequest acquired lock");
+      console.log("sending data to backend: "+data)
+      backend.stdin.write(data+'\n', (error) => {
+        done();
+        if (error) {
+          reject(error);
+        } else {
+          resolve();
+        }
+      });
+    });
+  });
+}
+
+function GetResult(session_token,operation_token) {
+  console.log("GetResult called");
+  while(true)
+  {
+    if(message_map.has(session_token))
+    {
+      if(message_map.get(session_token).has(operation_token))
+      {
+        const ret=message_map.get(session_token).get(operation_token);
+        message_map.get(session_token).delete(operation_token);
+        return ret;
+      }
+    }
+    sleep(100);
+  }
+}
+let buffer = '';
+const response_queue=new Queue();
+backend.stdout.on('data', (data) => {
+  console.log(`stdout: ${data}`);
+  buffer += data.toString();
+  while (buffer.includes('\n')) {
+      const lineEnd = buffer.indexOf('\n');
+      const line = buffer.slice(0, lineEnd);
+      buffer = buffer.slice(lineEnd + 1);
+      console.log(`C++ Program Output: ${line}`);
+      response_queue.enqueue(line);
+  }
+});
+// SendRequest("#OpenSession InnerTest")
 app.get('/', (req, res) => {
   res.sendFile(join(__dirname, 'index.html'));
 });
 
-io.on('connection', (socket) => {
+io.on('connection', async (socket) => {
   console.log('a user connected');
   socket.on('disconnect', () => {
     console.log('user disconnected');
   });
-  socket.on('chat message', (msg) => {
+  socket.on('request', async (msg) => {
     console.log('message: ' + msg);
-    socket.emit('chat message', '[self]'+msg);
-    socket.broadcast.emit('chat message', '[other]'+msg);
+    const substrings = msg.trim().split('\n')[0].split(' ');
+    const head=substrings[0];
+    if(head[1]=='S')
+    {
+      backend.stdin.write("#ShutDownSystem\n");
+      sleep(1000);
+      process.exit(0);
+    }
+    const session_token=substrings[1];
+    if(head[1]=='O')
+    {
+      SendRequest(msg);
+      ret=await GetResult(session_token,"Init");
+      console.log("ret: "+ret);
+      socket.emit('response', ret);
+    }
+    else{
+      const operation_token=substrings[2];
+      const outhentication_key=substrings[3];
+      const command=msg.trim().split('\n')[1];
+      console.log('head: ' + head);
+      console.log('session_token: ' + session_token);
+      console.log('operation_token: ' + operation_token);
+      console.log('outhentication_key: ' + outhentication_key);
+      console.log('command: ' + command);
+      console.log("sending request to backend")
+      SendRequest(msg);
+      if(!message_map.has(session_token)) message_map.set(session_token, new Map());
+      ret=await GetResult(session_token,operation_token);
+      console.log("ret: "+ret);
+      socket.emit('response', ret);
+    }
   });
 });