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webrtc学习笔记七(datachannel在jslinux的应用,nodejs版本)

程序员文章站 2022-07-08 16:42:22
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目标:
两个浏览器的jslinux可以进行数据交互
webrtc学习笔记七(datachannel在jslinux的应用,nodejs版本)
            
    
    博客分类: webrtclinux datachannelwebrtcjslinux 
webrtc学习笔记七(datachannel在jslinux的应用,nodejs版本)
            
    
    博客分类: webrtclinux datachannelwebrtcjslinux 

fabrice的jslinux是跑在浏览器中的linux,
提供了通过
/dev/clipboard 与<textare>交互的功能,交互的方法是clipboard_set

可以在jslinux.js中的clipboard_set方法中加入
datachannel的send方法,使两个浏览器中的textare有数据同步
从而是jslinux中通过一个linux的clipboard与另一个jslinux的clipboard交互

jslinux.js中修改的代码:
/* 
   Linux launcher

   Copyright (c) 2011-2012 Fabrice Bellard

   Redistribution or commercial use is prohibited without the author's
   permission.
*/
"use strict";

var term, pc, boot_start_time, init_state;

function term_start()
{
    term = new Term(80, 130, term_handler);

    term.open();
}

/* send chars to the serial port */
function term_handler(str)
{
    pc.serial.send_chars(str);
}
console.log("hao:version 1.2")
function clipboard_set(val)
{
	console.log("hao:clipboard_set---sendData->");
	
    var el;
    el = document.getElementById("text_clipboard");
    el.value = val;
    sendData();
}

function clipboard_get()
{
	console.log("hao:clipboard_get---->");
    var el;
    el = document.getElementById("text_clipboard");
    return el.value;
}

function clear_clipboard()
{
    var el;
    el = document.getElementById("text_clipboard");
    el.value = "";
}

/* just used to display the boot time in the VM */
function get_boot_time()
{
    return (+new Date()) - boot_start_time;
}

function start()
{
    var params;
    
    init_state = new Object();

    params = new Object();

    /* serial output chars */
    params.serial_write = term.write.bind(term);

    /* memory size (in bytes) */
    params.mem_size = 16 * 1024 * 1024;

    /* clipboard I/O */
    params.clipboard_get = clipboard_get;
    params.clipboard_set = clipboard_set;

    params.get_boot_time = get_boot_time;

    /* IDE drive. The raw disk image is split into files of
     * 'block_size' KB. 
     */
    params.hda = { url: "bin/hda%d.bin", block_size: 64, nb_blocks: 912 };
    
    pc = new PCEmulator(params);

    init_state.params = params;

    //pc.load_binary("vmlinux-2.6.20.bin", 0x00100000, start2);
    //pc.load_binary("vmlinux26.bin", 0x00100000, start2);
//    pc.load_binary("vmlinuxtest.bin", 0x00100000, start2);
    //pc.load_binary("vmlinuxnono.bin", 0x00100000, start2);
    //pc.load_binary("vmlinux319.bin", 0x00100000, start2);
    pc.load_binary("vmlinux319clip.bin", 0x00100000, start2);
}

function start2(ret)
{
    if (ret < 0)
        return;
    init_state.start_addr = 0x10000;
    //pc.load_binary("linuxstartnew.bin", init_state.start_addr, start3);
    pc.load_binary("linuxstart.bin", init_state.start_addr, start3);
}

function start3(ret)
{
    var block_list;
    if (ret < 0)
        return;
    /* Preload blocks so that the boot time does not depend on the
     * time to load the required disk data (optional) */
    block_list = [ 0, 7, 3, 643, 720, 256, 336, 644, 781, 387, 464, 475, 131, 589, 468, 472, 474, 776, 777, 778, 779, 465, 466, 473, 467, 469, 470, 512, 592, 471, 691, 697, 708, 792, 775, 769 ];
    pc.ide0.drives[0].bs.preload(block_list, start4);
}

function start4(ret)
{
    var cmdline_addr;

    if (ret < 0)
        return;

    /* set the Linux kernel command line */
    cmdline_addr = 0xf800;
    pc.cpu.write_string(cmdline_addr, "console=ttyS0 root=/dev/hda ro init=/sbin/init notsc=1 hdb=none");

    pc.cpu.eip = init_state.start_addr;
    pc.cpu.regs[0] = init_state.params.mem_size; /* eax */
    pc.cpu.regs[3] = 0; /* ebx = initrd_size (no longer used) */
    pc.cpu.regs[1] = cmdline_addr; /* ecx */

    boot_start_time = (+new Date());

    pc.start();
}

term_start();



jslinux的html修改的代码:
<!DOCTYPE html>
<html>
<head>
<title>Javascript PC Emulator</title>
<style>
.term {
    font-family: courier,fixed,swiss,monospace,sans-serif;
    font-size: 14px;
    color: #f0f0f0;
    background: #000000;
}

.termReverse {
    color: #000000;
    background: #00ff00;
}
#note {
    font-size: 12px;
}
#copyright {
    font-size: 10px;
}
#clipboard {
    font-size: 12px;
}
</style>
</head>
<body >
<table border="0">
<tr valign="top"><td>
<script type="text/javascript" src="jquery.js"></script>  
<script type="text/javascript" src="utils.js"></script>
<script type="text/javascript" src="term.js"></script>
<script type="text/javascript" src="cpux86.js"></script>
<script type="text/javascript" src="jslinux.js"></script>


<div id="copyright">&copy; 2011 Fabrice Bellard - <a href="news.html">News</a> - <a href="faq.html">FAQ</a> - <a href="tech.html">Technical notes</a></div>
<input type="button" value="Clear clipboard" onclick="clear_clipboard();"><br><textarea row="4" cols="16" id="text_clipboard" ></textarea></br>
<input type="button" value="addletter" onclick="addletter();">
<input type="button" value="start" onclick="start();">


</table>
<script type="text/javascript" >
		
		function addletter(){
			document.getElementById("text_clipboard").value=document.getElementById("text_clipboard").value+"a";
		}
		$('#text_clipboard').bind('input propertychange', function() {  
		    //$('#result').html($(this).val().length + ' characters');  
		    sendData();
		});
		var iceServer = null;
		var pc = new window.webkitRTCPeerConnection(iceServer,{optional: [{RtpDataChannels: true}]});
		
        var isCaller = window.location.href.split('#')[1];
        var socket = new WebSocket("ws://192.168.137.27:3000");
        socket.onmessage = function(event){
            var json = JSON.parse(event.data);
            //console.log('onmessage: ', json);
            //如果是一个ICE的候选,则将其加入到PeerConnection中,否则设定对方的session描述为传递过来的描述
            if( json.event === "_ice_candidate" ){
                pc.addIceCandidate(new RTCIceCandidate(json.data.candidate));
            } else {
                pc.setRemoteDescription(new RTCSessionDescription(json.data.sdp));
                console.log("---------------->pc.setRemote");
                // 如果是一个offer,那么需要回复一个answer
                if(json.event === "_offer") {
                	console.log("------->createAnswer");
                    pc.createAnswer(function(desc){
			            pc.setLocalDescription(desc);
			            console.log("---------------->pc.setLocal");
			            socket.send(JSON.stringify({ 
			                "event": "_answer",
			                "data": {
			                    "sdp": desc
			                }
			            }));
			        }, function (error) {
                        console.log('Failure callback: ' + error);
                    });
                }else{
                	console.log("------->receive Answer---('"+json.event+"')");
                }
                
            }
        };
        
        
        try {
		    sendChannel = pc.createDataChannel('sendDataChannel',{reliable: true});
		} catch (e) {
		    alert('createDataChannel() failed with exception: ' + e.message);
		}
		sendChannel.onopen = console.log('--Send channel open state is : ' +sendChannel.readyState);
  		sendChannel.onclose = console.log('--Send channel close  state is: ' +sendChannel.readyState);
        // 发送ICE候选到其他客户端
        pc.onicecandidate = function(event){
        	console.log("onicecandidate----------->");
            if (event.candidate !== null) {
            	console.log("event.candidate   !=   null");
                socket.send(JSON.stringify({
                    "event": "_ice_candidate",
                    "data": {
                        "candidate": event.candidate
                    }
                }));
            }else{
            	console.log("event.candidate   == null");
            }
        };
    	sendChannel.onmessage = function(event) {
    		  console.log("-sendChannel.onmessage--★★★★★");
   			  document.getElementById('text_clipboard').value = event.data;
		};
        function sendData() {
		  var data = document.getElementById('text_clipboard').value;
		  console.log("---->>>>sendData():"+data);
		  sendChannel.send(data);
		}
		if(isCaller){
        	console.log("------->createOffer");
            pc.createOffer(function(desc){
            //	console.log(desc);
	            pc.setLocalDescription(desc);
	            console.log("---------------->pc.setLocal");
	            socket.send(JSON.stringify({ 
	                "event": "_offer",
	                "data": {
	                    "sdp": desc
	                }
	            }));
	        }, function (error) {
                console.log('Failure callback: ' + error);
            });
        }
        
		console.log("---over");
</script>
<!--button id="sendButton" onclick="sendData()">Send</button>
<textarea id="dataChannelSend" >abc</textarea>
<div id="result"></div--> 

</body>
</html>


在建立datachannel的时候使用的websocket 的node的代码:
//http://www.blogjava.net/linli/archive/2014/10/21/418910.html
var express = require('express'),
app = express(),
server = require('http').createServer(app);

server.listen(3000);

app.get('/', function(req, res) {
    res.sendfile(__dirname + '/webrtc.html');
});

var WebSocketServer = require('ws').Server,
wss = new WebSocketServer({server: server});
function writeObj(obj){ 
    var description = ""; 
    for(var i in obj){   
        var property=obj[i];   
        description+=i+" = "+property+"\n";  
    }   
    console.log(description); 
} 
// 存储socket的数组,这里只能有2个socket,每次测试需要重启,否则会出错
var wsc = [],
index = 1;
// 有socket连入
wss.on('connection', function(ws) {
    console.log('connection:');
    //writeObj(ws);
    // 将socket存入数组
    wsc.push(ws);
    // 记下对方socket在数组中的下标,因为这个测试程序只允许2个socket
    // 所以第一个连入的socket存入0,第二个连入的就是存入1
    // otherIndex就反着来,第一个socket的otherIndex下标为1,第二个socket的otherIndex下标为0
    var otherIndex = index--,
    desc = null;

    if (otherIndex == 1) {
        desc = 'first socket';
    } else {
        desc = 'second socket';
    }
    // 转发收到的消息
    ws.on('message', function(message) {
        var json = JSON.parse(message);
        //console.log('received (' + desc + '): ', json);
        console.log('otherIndex ---('+desc+')(' + otherIndex + '): '+json.event);
        wsc[otherIndex].send(message, function (error) {
            if (error) {
                console.log('Send message error (' + desc + '): ', error);
            }
        });
    });
});




测试,只有chrome可用
1.先在服务器上启动
node server.js
代码不完善,只能两台机器测试

2.一台电脑的chrome
http://192.168.137.27:8081/jslinux/webrtc2.html
另一台
http://192.168.137.27:8081/jslinux/webrtc2.html#true
看console的datachannel建立后
3.start启动vm

4.在一台vm中
tail -f /dev/clipboard
另一台中
echo "hahahahaha" > /dev/clipboard

看第一台机器中的clipboard是否接受到值


jslinux.zip 随便解压到tomcat或者nginx中即可使用,server.js是建立datachannle的时候时候用的websocke
  • webrtc学习笔记七(datachannel在jslinux的应用,nodejs版本)
            
    
    博客分类: webrtclinux datachannelwebrtcjslinux 
  • 大小: 44.4 KB
  • webrtc学习笔记七(datachannel在jslinux的应用,nodejs版本)
            
    
    博客分类: webrtclinux datachannelwebrtcjslinux 
  • 大小: 32.7 KB