ExBuffer

ExBuffer，NodeJs的TCP中的粘包、分包问题的解决方案！

推荐结合ByteBuffer来做通信协议！https://github.com/play175/ByteBuffer

C版本的ExBuffer：https://github.com/play175/exbuffer.c

``javascript
var ExBuffer = require('./ExBuffer');

/基本操作*/

//构造一个ExBuffer，采用4个字节（uint32无符号整型）表示包长，而且是little endian 字节序
var exBuffer = new ExBuffer().uint32Head().littleEndian();
//或者构造一个ExBuffer，采用2个字节（ushort型）表示包长，而且是big endian 字节序 (默认)
var exBuffer = new ExBuffer().ushortHead().bigEndian();

//只要收到满足的包就会触发事件
exBuffer.on('data',function(buffer){
console.log('>> receive data,length:'+buffer.length);
//console.log(buffer);
});


//传入一个9字节长的数据，分多次put （对应于TCP中的分包的情况）
exBuffer.put(new Buffer([0,9]));
exBuffer.put(new Buffer([1,2,3,4,5,6,7]));
exBuffer.put(new Buffer([8,9]));

//传入一个3个字节的数据和一个6个字节的数据，一次put（对应于TCP中的粘包的情况）
exBuffer.put(new Buffer([0,3,1,2,3,0,6,1,2,3,4,5,6]));


//大数据处理测试 (20MB)
var exBuffer = new ExBuffer().uint32Head().bigEndian();
exBuffer.on('data',function(buffer){
console.log('>> receive data,length:'+buffer.length);
console.log(buffer);
});
var sbuf = new Buffer(4);
sbuf.writeUInt32BE(1024102420,0);//写入包长
exBuffer.put(sbuf);
exBuffer.put(new Buffer(1024102420));


/在socket中的应用*/

console.log('-----------------------use in socket------------------------');

var net = require('net');

//测试服务端
var server = net.createServer(function(socket) {
console.log('client connected');
new Connection(socket);//有客户端连入时
});
server.listen(8124);

//服务端中映射客户端的类
function Connection(socket) {
var exBuffer = new ExBuffer();
exBuffer.on('data',onReceivePackData);

socket.on('data', function(data) {
exBuffer.put(data);//只要收到数据就往ExBuffer里面put
});

//当服务端收到完整的包时
function onReceivePackData(buffer){
console.log('>> server receive data,length:'+buffer.length);
console.log(buffer.toString());

var data = 'wellcom, I am server';
var len = Buffer.byteLength(data);

//写入2个字节表示本次包长
var headBuf = new Buffer(2);
headBuf.writeUInt16BE(len, 0)
socket.write(headBuf);

var bodyBuf = new Buffer(len);
bodyBuf.write(data);
socket.write(bodyBuf);
}
}

//测试客户端
var exBuffer = new ExBuffer();
var client = net.connect(8124, function() {

var data = 'hello I am client';
var len = Buffer.byteLength(data);

//写入2个字节表示本次包长
var headBuf = new Buffer(2);
headBuf.writeUInt16BE(len, 0)
client.write(headBuf);

var bodyBuf = new Buffer(len);
bodyBuf.write(data);
client.write(bodyBuf);

});

client.on('data', function(data) {
exBuffer.put(data);//只要收到数据就往ExBuffer里面put
});

//当客户端收到完整的数据包时
exBuffer.on('data', function(buffer) {
console.log('>> client receive data,length:'+buffer.length);
console.log(buffer.toString());
});

`

安装

`javascript
npm install ExBuffer
``