2012-02-10 61 views
0

我试图管理一堆套接字连接。我的应用基本上是一个http服务器,它接收帖子并将它们传递给套接字。当客户端打开一个套接字连接,它们发送连接消息的ID:在Node.js中创建ID到套接字的映射,反之亦然

{"m":"connect","id":"1"} 

的应用程序,然后保存该ID和插座在id2socket和socket2id地图。断开连接时,套接字/ ID对将从地图中删除。

一个帖子也会包含一个id,它表明发布的数据应该被发送到具有该id的套接字。

这很好,这对于单个打开的套接字可以很好地工作。但是,当我打开多个套接字,然后关闭一个套接字时,该断开连接将擦除地图上的所有内容。我认为我对节点中的套接字的理解是不完整的 - 在回调中是否只有一个套接字对象?有没有更好的方法来管理我的开放式套接字连接和ID?

启动服务器:

>>node server.js 
TCP server listening on 127.0.0.1:5280 
HTTP server listening on 127.0.0.1:9002 

的telnet在:

连接后
>>telnet localhost 5280 
Trying 127.0.0.1... 
Connected to localhost. 
Escape character is '^]'. 
{"m":"connect","id":"123"} 
{"m":"connect","id":"123","success":"true"} 

服务器:

>>Connection from 127.0.0.1:57572 
received data: {"m":"connect","id":"123"} 

id: 1 
m: connect 
associating uid 1 with socket [object Object] 

做一个帖子:

python post.py {"foo":"bar"} 

因此,这适用于多个开放套接字(只要1设备是ID 123,服务器现在这硬连线)。但是,只要关闭一个连接,所有套接字连接都将从地图中删除。

这里是我的代码:

python脚本做后:

import sys 
import json 
import httplib, urllib, urllib2 

values = json.loads('{"foo":"bar"}') 
headers = {"Content-type": "application/json"} 

conn = httplib.HTTPConnection('127.0.0.1', 9002) 
headers = {"Content-type": "application/json"} 
conn.request("POST", "", json.dumps(values), headers) 
response = conn.getresponse() 

print "response.status: "+response.status 
print "response.reason: "+response.reason 
print "response.read: "+response.read() 
conn.close() 

节点服务器(HTTP和TCP),硬连接将数据发送到设备 '123' 上一篇:

var net = require('net'); // tcp-server 
var http = require("http"); // http-server 
var qs = require('querystring'); // http-post 

// Map of sockets to devices 
var id2socket = new Object; 
var socket2id = new Object; 

// Setup a tcp server 
var server_plug = net.createServer(function(socket) { 

    // Event handlers 
    socket.addListener("connect", function(conn) { 
     console.log("Connection from " + socket.remoteAddress + ":" + socket.remotePort); 
    }); 

    socket.addListener("data", function(data) { 
     console.log("received data: " + data); 
     try { 
      request = JSON.parse(data); 

      response = request; 
      if(request.m !== undefined && request['id'] !== undefined){ // hack on 'id', id is js obj property 
       console.log("id: "+request['id']); 
       console.log("m: "+request.m); 
       if(request.m == 'connect'){ 
        console.log("associating uid " + request['id'] + " with socket " + socket); 
        id2socket[request['id']] = socket; 
        socket2id[socket] = request['id']; 
        response.success = 'true'; 
       } else { 
        response.success = 'true'; 
       } 
      } 
      socket.write(JSON.stringify(response)); 
     } catch (SyntaxError) { 
      console.log('Invalid JSON:' + data); 
      socket.write('{"success":"false","response":"invalid JSON"}'); 
     } 
    }); 

    socket.on('end', function() { 
     id = socket2id[socket] 
     console.log("socket disconnect by id " + id); 

     // wipe out the stored info 
     console.log("removing from map socket:"+socket+" id:"+id); 
     delete id2socket[id]; 
     delete socket2id[socket]; 
    }); 

    socket.on('timeout', function() { 
     console.log('socket timeout'); 
    }); 

}); 

// Setup http server 
var server_http = http.createServer(
    // Function to handle http:post requests, need two parts to it 
    // http://jnjnjn.com/113/node-js-for-noobs-grabbing-post-content/ 
    function onRequest(request, response) { 
     request.setEncoding("utf8"); 

     request.addListener("data", function(chunk) { 
      request.content += chunk; 
     }); 

     request.addListener("end", function() { 
      console.log("post received!"); 
      //console.log("Request received: "+request.content); 


      if (request.method == 'POST') { 
       //var json = qs.parse(request.content); 
       //console.log("Post: "+json); 

       // HACK TO TEST STUFF: 
       // send a message to one of the open sockets 
       try { 
        var socket = id2socket['123']; //hardwired 
        socket.write('{"m":"post"}'); 
       } catch (Error) { 
        console.log("Cannot find socket with id "+'123'); 
       } 
      } 
     }); 
    } 
); 


// Fire up the servers 
var HOST = '127.0.0.1'; 
var PORT = 5280; 
var PORT2 = 9002; 

server_plug.listen(PORT, HOST); 
console.log("TCP server listening on "+HOST+":"+PORT); 

server_http.listen(PORT2); 
console.log("HTTP server listening on "+HOST+":"+PORT2); 

回答

1

对象只将字符串作为其属性的键。如您的日志所示,套接字对象被转换为字符串"[object Object]"。因此,套接字#2将覆盖对象中套接字1的id,因为所有套接字都转换为相同的字符串关键字。因此,对象中始终只有一个属性,因为所有套接字都归入同一个关键字。当您尝试删除套接字2的ID时,单个属性将被删除并且该对象为空。

你似乎想为每个单独的套接字使用一个自定义属性作为关键。您可以使用WeakMapWeakMap s确实允许对象作为键(而不是字符串键),但由于它们相对较新,它们可能包含当前的错误。 (请注意,id2socket映射只能是一个普通对象,因为数字转换为字符串就好了,每个数字都有自己的不同的字符串表示形式*。)

使用WeakMap s是如下:

var socket2id = new WeakMap; // as if you were doing: var socket2id = {}; 
socket2id.set(socket, id); // as if you were doing: socket2id[socket] = id; 
socket2id.get(socket);  // as if you were doing: socket2id[socket]; 
socket2id.delete(socket); // as if you were doing: delete socket2id[socket]; 

确保用node --harmony运行(> = 0.7)或node --harmony_weakmaps(< = 0.6)。


*0-0有例外,但你不应该使用-0反正因为0 === -0,所以很难在它们之间的不同。

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