76 lines
2.8 KiB
JavaScript
76 lines
2.8 KiB
JavaScript
|
// https://github.com/websockets/ws/issues/596
|
||
|
|
var WSStream = module.exports = (function(){
|
||
|
|
var util = require('util');
|
||
|
|
var stream = require('stream');
|
||
|
|
var Duplex = stream.Duplex || require('readable-stream').Duplex;
|
||
|
|
var WSStream = function(ws, wsOptions, streamingOptions) { // Only the websocket (ws) is mandatory
|
||
|
|
// Proper duplex stream with automatic flow control (backpressure) management
|
||
|
|
if(!(this instanceof WSStream)) return new WSStream(ws, wsOptions, streamingOptions);
|
||
|
|
if(!(wsOptions instanceof Object)) wsOptions = {binary: false};
|
||
|
|
Duplex.call(this, streamingOptions);
|
||
|
|
this.waitingForData = true;
|
||
|
|
this.writeModBufferEmpty = true;
|
||
|
|
this.webSocket = ws;
|
||
|
|
this.webSocketOptions = wsOptions;
|
||
|
|
this.on('finish', finishEventHandler(this));
|
||
|
|
ws._socket.write = writeMod(ws._socket.write, this);
|
||
|
|
ws._socket.on('drain', drainEventHandler(this));
|
||
|
|
ws._socket.on('error', errorRouter(this));
|
||
|
|
ws.on('close', closeEventHandler(this));
|
||
|
|
ws.on('message', messageHandler(this));
|
||
|
|
},
|
||
|
|
finishEventHandler = function(self) {
|
||
|
|
return function() {
|
||
|
|
if(self.webSocket !== null) {
|
||
|
|
self.webSocket.close();
|
||
|
|
self.webSocket = null;
|
||
|
|
};
|
||
|
|
self.emit('close');
|
||
|
|
};
|
||
|
|
},
|
||
|
|
writeMod = function(nativeWriteFunction, self) {
|
||
|
|
return function() {
|
||
|
|
return self.writeModBufferEmpty = nativeWriteFunction.apply(this, arguments);
|
||
|
|
};
|
||
|
|
},
|
||
|
|
drainEventHandler = function(self) {
|
||
|
|
return function() {
|
||
|
|
self.writeModBufferEmpty = true;
|
||
|
|
self.emit('drain');
|
||
|
|
};
|
||
|
|
},
|
||
|
|
closeEventHandler = function(self) {
|
||
|
|
return function() {
|
||
|
|
self.push(null);
|
||
|
|
}
|
||
|
|
},
|
||
|
|
errorRouter = function(self) {
|
||
|
|
return function() {
|
||
|
|
self.emit.apply(self, ['error'].concat(arguments));
|
||
|
|
};
|
||
|
|
},
|
||
|
|
messageHandler = function(self) {
|
||
|
|
return function(data) {
|
||
|
|
if(!self.push(data) && self.waitingForData) {
|
||
|
|
self.webSocket._socket.pause();
|
||
|
|
self.waitingForData = false;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
};
|
||
|
|
util.inherits(WSStream, Duplex);
|
||
|
|
WSStream.prototype._read = function(size) {
|
||
|
|
if(!this.waitingForData) {
|
||
|
|
this.waitingForData = true;
|
||
|
|
this.webSocket._socket.resume();
|
||
|
|
}
|
||
|
|
};
|
||
|
|
WSStream.prototype._write = function(chunk, encoding, callback) {
|
||
|
|
this.webSocket.send(chunk, this.webSocketOptions, callback);
|
||
|
|
return this.writeModBufferEmpty;
|
||
|
|
};
|
||
|
|
return WSStream;
|
||
|
|
}());
|
||
|
|
module.exports.create = function (ws, wsOpts, streamOpts) {
|
||
|
|
return new WSStream(ws, wsOpts, streamOpts);
|
||
|
|
};
|