/*!
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* ws: a node.js websocket client
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* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
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* MIT Licensed
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*/
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var util = require('util')
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, Validation = require('./Validation').Validation
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, ErrorCodes = require('./ErrorCodes')
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, BufferPool = require('./BufferPool')
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, bufferUtil = require('./BufferUtil').BufferUtil;
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/**
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* Node version 0.4 and 0.6 compatibility
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*/
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var isNodeV4 = /^v0\.4/.test(process.version);
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/**
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* HyBi Receiver implementation
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*/
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function Receiver () {
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// memory pool for fragmented messages
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var fragmentedPoolPrevUsed = -1;
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this.fragmentedBufferPool = new BufferPool(1024, function(db, length) {
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return db.used + length;
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}, function(db) {
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return fragmentedPoolPrevUsed = fragmentedPoolPrevUsed >= 0 ?
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(fragmentedPoolPrevUsed + db.used) / 2 :
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db.used;
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});
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// memory pool for unfragmented messages
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var unfragmentedPoolPrevUsed = -1;
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this.unfragmentedBufferPool = new BufferPool(1024, function(db, length) {
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return db.used + length;
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}, function(db) {
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return unfragmentedPoolPrevUsed = unfragmentedPoolPrevUsed >= 0 ?
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(unfragmentedPoolPrevUsed + db.used) / 2 :
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db.used;
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});
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this.state = {
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activeFragmentedOperation: null,
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lastFragment: false,
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masked: false,
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opcode: 0,
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fragmentedOperation: false
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};
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this.overflow = [];
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this.headerBuffer = new Buffer(10);
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this.expectOffset = 0;
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this.expectBuffer = null;
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this.expectHandler = null;
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this.currentMessage = [];
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this.expectHeader(2, this.processPacket);
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this.dead = false;
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this.onerror = function() {};
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this.ontext = function() {};
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this.onbinary = function() {};
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this.onclose = function() {};
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this.onping = function() {};
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this.onpong = function() {};
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};
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module.exports = Receiver;
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/**
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* Add new data to the parser.
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*
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* @api public
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*/
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Receiver.prototype.add = function(data) {
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var dataLength = data.length;
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if (dataLength == 0) return;
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if (this.expectBuffer == null) {
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this.overflow.push(data);
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return;
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}
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var toRead = Math.min(dataLength, this.expectBuffer.length - this.expectOffset);
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fastCopy(toRead, data, this.expectBuffer, this.expectOffset);
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this.expectOffset += toRead;
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if (toRead < dataLength) {
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this.overflow.push(data.slice(toRead));
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}
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while (this.expectBuffer && this.expectOffset == this.expectBuffer.length) {
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var bufferForHandler = this.expectBuffer;
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this.expectBuffer = null;
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this.expectOffset = 0;
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this.expectHandler.call(this, bufferForHandler);
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}
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}
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/**
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* Releases all resources used by the receiver.
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*
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* @api public
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*/
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Receiver.prototype.cleanup = function() {
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this.dead = true;
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this.overflow = null;
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this.headerBuffer = null;
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this.expectBuffer = null;
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this.expectHandler = null;
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this.unfragmentedBufferPool = null;
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this.fragmentedBufferPool = null;
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this.state = null;
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this.currentMessage = null;
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this.onerror = null;
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this.ontext = null;
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this.onbinary = null;
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this.onclose = null;
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this.onping = null;
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this.onpong = null;
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}
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/**
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* Waits for a certain amount of header bytes to be available, then fires a callback.
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*
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* @api private
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*/
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Receiver.prototype.expectHeader = function(length, handler) {
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if (length == 0) {
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handler(null);
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return;
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}
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this.expectBuffer = this.headerBuffer.slice(this.expectOffset, this.expectOffset + length);
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this.expectHandler = handler;
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var toRead = length;
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while (toRead > 0 && this.overflow.length > 0) {
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var fromOverflow = this.overflow.pop();
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if (toRead < fromOverflow.length) this.overflow.push(fromOverflow.slice(toRead));
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var read = Math.min(fromOverflow.length, toRead);
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fastCopy(read, fromOverflow, this.expectBuffer, this.expectOffset);
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this.expectOffset += read;
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toRead -= read;
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}
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}
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/**
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* Waits for a certain amount of data bytes to be available, then fires a callback.
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*
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* @api private
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*/
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Receiver.prototype.expectData = function(length, handler) {
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if (length == 0) {
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handler(null);
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return;
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}
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this.expectBuffer = this.allocateFromPool(length, this.state.fragmentedOperation);
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this.expectHandler = handler;
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var toRead = length;
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while (toRead > 0 && this.overflow.length > 0) {
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var fromOverflow = this.overflow.pop();
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if (toRead < fromOverflow.length) this.overflow.push(fromOverflow.slice(toRead));
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var read = Math.min(fromOverflow.length, toRead);
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fastCopy(read, fromOverflow, this.expectBuffer, this.expectOffset);
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this.expectOffset += read;
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toRead -= read;
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}
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}
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/**
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* Allocates memory from the buffer pool.
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*
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* @api private
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*/
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Receiver.prototype.allocateFromPool = !isNodeV4
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? function(length, isFragmented) { return (isFragmented ? this.fragmentedBufferPool : this.unfragmentedBufferPool).get(length); }
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: function(length) { return new Buffer(length); };
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/**
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* Start processing a new packet.
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*
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* @api private
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*/
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Receiver.prototype.processPacket = function (data) {
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if ((data[0] & 0x70) != 0) {
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this.error('reserved fields must be empty', 1002);
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return;
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}
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this.state.lastFragment = (data[0] & 0x80) == 0x80;
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this.state.masked = (data[1] & 0x80) == 0x80;
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var opcode = data[0] & 0xf;
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if (opcode === 0) {
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// continuation frame
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this.state.fragmentedOperation = true;
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this.state.opcode = this.state.activeFragmentedOperation;
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if (!(this.state.opcode == 1 || this.state.opcode == 2)) {
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this.error('continuation frame cannot follow current opcode', 1002);
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return;
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}
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}
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else {
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if (opcode < 3 && this.state.activeFragmentedOperation != null) {
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this.error('data frames after the initial data frame must have opcode 0', 1002);
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return;
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}
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this.state.opcode = opcode;
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if (this.state.lastFragment === false) {
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this.state.fragmentedOperation = true;
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this.state.activeFragmentedOperation = opcode;
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}
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else this.state.fragmentedOperation = false;
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}
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var handler = opcodes[this.state.opcode];
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if (typeof handler == 'undefined') this.error('no handler for opcode ' + this.state.opcode, 1002);
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else {
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handler.start.call(this, data);
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}
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}
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/**
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* Endprocessing a packet.
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*
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* @api private
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*/
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Receiver.prototype.endPacket = function() {
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if (!this.state.fragmentedOperation) this.unfragmentedBufferPool.reset(true);
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else if (this.state.lastFragment) this.fragmentedBufferPool.reset(false);
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this.expectOffset = 0;
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this.expectBuffer = null;
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this.expectHandler = null;
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if (this.state.lastFragment && this.state.opcode === this.state.activeFragmentedOperation) {
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// end current fragmented operation
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this.state.activeFragmentedOperation = null;
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}
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this.state.lastFragment = false;
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this.state.opcode = this.state.activeFragmentedOperation != null ? this.state.activeFragmentedOperation : 0;
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this.state.masked = false;
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this.expectHeader(2, this.processPacket);
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}
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/**
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* Reset the parser state.
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*
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* @api private
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*/
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Receiver.prototype.reset = function() {
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if (this.dead) return;
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this.state = {
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activeFragmentedOperation: null,
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lastFragment: false,
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masked: false,
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opcode: 0,
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fragmentedOperation: false
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};
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this.fragmentedBufferPool.reset(true);
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this.unfragmentedBufferPool.reset(true);
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this.expectOffset = 0;
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this.expectBuffer = null;
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this.expectHandler = null;
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this.overflow = [];
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this.currentMessage = [];
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}
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/**
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* Unmask received data.
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*
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* @api private
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*/
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Receiver.prototype.unmask = function (mask, buf, binary) {
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if (mask != null && buf != null) bufferUtil.unmask(buf, mask);
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if (binary) return buf;
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return buf != null ? buf.toString('utf8') : '';
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}
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/**
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* Concatenates a list of buffers.
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*
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* @api private
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*/
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Receiver.prototype.concatBuffers = function(buffers) {
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var length = 0;
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for (var i = 0, l = buffers.length; i < l; ++i) length += buffers[i].length;
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var mergedBuffer = new Buffer(length);
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bufferUtil.merge(mergedBuffer, buffers);
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return mergedBuffer;
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}
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/**
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* Handles an error
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*
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* @api private
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*/
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Receiver.prototype.error = function (reason, protocolErrorCode) {
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this.reset();
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this.onerror(reason, protocolErrorCode);
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return this;
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}
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/**
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* Buffer utilities
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*/
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function readUInt16BE(start) {
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return (this[start]<<8) +
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this[start+1];
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}
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function readUInt32BE(start) {
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return (this[start]<<24) +
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(this[start+1]<<16) +
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(this[start+2]<<8) +
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this[start+3];
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}
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function fastCopy(length, srcBuffer, dstBuffer, dstOffset) {
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switch (length) {
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default: srcBuffer.copy(dstBuffer, dstOffset, 0, length); break;
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case 16: dstBuffer[dstOffset+15] = srcBuffer[15];
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case 15: dstBuffer[dstOffset+14] = srcBuffer[14];
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case 14: dstBuffer[dstOffset+13] = srcBuffer[13];
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case 13: dstBuffer[dstOffset+12] = srcBuffer[12];
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case 12: dstBuffer[dstOffset+11] = srcBuffer[11];
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case 11: dstBuffer[dstOffset+10] = srcBuffer[10];
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case 10: dstBuffer[dstOffset+9] = srcBuffer[9];
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case 9: dstBuffer[dstOffset+8] = srcBuffer[8];
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case 8: dstBuffer[dstOffset+7] = srcBuffer[7];
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case 7: dstBuffer[dstOffset+6] = srcBuffer[6];
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case 6: dstBuffer[dstOffset+5] = srcBuffer[5];
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case 5: dstBuffer[dstOffset+4] = srcBuffer[4];
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case 4: dstBuffer[dstOffset+3] = srcBuffer[3];
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case 3: dstBuffer[dstOffset+2] = srcBuffer[2];
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case 2: dstBuffer[dstOffset+1] = srcBuffer[1];
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case 1: dstBuffer[dstOffset] = srcBuffer[0];
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}
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}
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/**
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* Opcode handlers
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*/
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var opcodes = {
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// text
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'1': {
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start: function(data) {
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var self = this;
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// decode length
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var firstLength = data[1] & 0x7f;
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if (firstLength < 126) {
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opcodes['1'].getData.call(self, firstLength);
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}
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else if (firstLength == 126) {
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self.expectHeader(2, function(data) {
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opcodes['1'].getData.call(self, readUInt16BE.call(data, 0));
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});
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}
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else if (firstLength == 127) {
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self.expectHeader(8, function(data) {
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if (readUInt32BE.call(data, 0) != 0) {
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self.error('packets with length spanning more than 32 bit is currently not supported', 1008);
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return;
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}
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opcodes['1'].getData.call(self, readUInt32BE.call(data, 4));
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});
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}
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},
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getData: function(length) {
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var self = this;
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if (self.state.masked) {
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self.expectHeader(4, function(data) {
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var mask = data;
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self.expectData(length, function(data) {
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opcodes['1'].finish.call(self, mask, data);
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});
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});
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}
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else {
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self.expectData(length, function(data) {
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opcodes['1'].finish.call(self, null, data);
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});
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}
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},
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finish: function(mask, data) {
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var packet = this.unmask(mask, data, true);
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if (packet != null) this.currentMessage.push(packet);
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if (this.state.lastFragment) {
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var messageBuffer = this.concatBuffers(this.currentMessage);
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if (!Validation.isValidUTF8(messageBuffer)) {
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this.error('invalid utf8 sequence', 1007);
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return;
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}
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this.ontext(messageBuffer.toString('utf8'), {masked: this.state.masked, buffer: messageBuffer});
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this.currentMessage = [];
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}
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this.endPacket();
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}
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},
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// binary
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'2': {
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start: function(data) {
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var self = this;
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// decode length
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var firstLength = data[1] & 0x7f;
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if (firstLength < 126) {
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opcodes['2'].getData.call(self, firstLength);
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}
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else if (firstLength == 126) {
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self.expectHeader(2, function(data) {
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opcodes['2'].getData.call(self, readUInt16BE.call(data, 0));
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});
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}
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else if (firstLength == 127) {
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self.expectHeader(8, function(data) {
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if (readUInt32BE.call(data, 0) != 0) {
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self.error('packets with length spanning more than 32 bit is currently not supported', 1008);
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return;
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}
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opcodes['2'].getData.call(self, readUInt32BE.call(data, 4, true));
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});
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}
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},
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getData: function(length) {
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var self = this;
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if (self.state.masked) {
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self.expectHeader(4, function(data) {
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var mask = data;
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self.expectData(length, function(data) {
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opcodes['2'].finish.call(self, mask, data);
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});
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});
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}
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else {
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self.expectData(length, function(data) {
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opcodes['2'].finish.call(self, null, data);
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});
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}
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},
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finish: function(mask, data) {
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var packet = this.unmask(mask, data, true);
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if (packet != null) this.currentMessage.push(packet);
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if (this.state.lastFragment) {
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var messageBuffer = this.concatBuffers(this.currentMessage);
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this.onbinary(messageBuffer, {masked: this.state.masked, buffer: messageBuffer});
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this.currentMessage = [];
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}
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this.endPacket();
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}
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},
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// close
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'8': {
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|
start: function(data) {
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var self = this;
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if (self.state.lastFragment == false) {
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self.error('fragmented close is not supported', 1002);
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return;
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}
|
|
|
|
// decode length
|
|
var firstLength = data[1] & 0x7f;
|
|
if (firstLength < 126) {
|
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opcodes['8'].getData.call(self, firstLength);
|
|
}
|
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else {
|
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self.error('control frames cannot have more than 125 bytes of data', 1002);
|
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}
|
|
},
|
|
getData: function(length) {
|
|
var self = this;
|
|
if (self.state.masked) {
|
|
self.expectHeader(4, function(data) {
|
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var mask = data;
|
|
self.expectData(length, function(data) {
|
|
opcodes['8'].finish.call(self, mask, data);
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});
|
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});
|
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}
|
|
else {
|
|
self.expectData(length, function(data) {
|
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opcodes['8'].finish.call(self, null, data);
|
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});
|
|
}
|
|
},
|
|
finish: function(mask, data) {
|
|
var self = this;
|
|
data = self.unmask(mask, data, true);
|
|
if (data && data.length == 1) {
|
|
self.error('close packets with data must be at least two bytes long', 1002);
|
|
return;
|
|
}
|
|
var code = data && data.length > 1 ? readUInt16BE.call(data, 0) : 1000;
|
|
if (!ErrorCodes.isValidErrorCode(code)) {
|
|
self.error('invalid error code', 1002);
|
|
return;
|
|
}
|
|
var message = '';
|
|
if (data && data.length > 2) {
|
|
var messageBuffer = data.slice(2);
|
|
if (!Validation.isValidUTF8(messageBuffer)) {
|
|
self.error('invalid utf8 sequence', 1007);
|
|
return;
|
|
}
|
|
message = messageBuffer.toString('utf8');
|
|
}
|
|
this.onclose(code, message, {masked: self.state.masked});
|
|
this.reset();
|
|
},
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|
},
|
|
// ping
|
|
'9': {
|
|
start: function(data) {
|
|
var self = this;
|
|
if (self.state.lastFragment == false) {
|
|
self.error('fragmented ping is not supported', 1002);
|
|
return;
|
|
}
|
|
|
|
// decode length
|
|
var firstLength = data[1] & 0x7f;
|
|
if (firstLength < 126) {
|
|
opcodes['9'].getData.call(self, firstLength);
|
|
}
|
|
else {
|
|
self.error('control frames cannot have more than 125 bytes of data', 1002);
|
|
}
|
|
},
|
|
getData: function(length) {
|
|
var self = this;
|
|
if (self.state.masked) {
|
|
self.expectHeader(4, function(data) {
|
|
var mask = data;
|
|
self.expectData(length, function(data) {
|
|
opcodes['9'].finish.call(self, mask, data);
|
|
});
|
|
});
|
|
}
|
|
else {
|
|
self.expectData(length, function(data) {
|
|
opcodes['9'].finish.call(self, null, data);
|
|
});
|
|
}
|
|
},
|
|
finish: function(mask, data) {
|
|
this.onping(this.unmask(mask, data, true), {masked: this.state.masked, binary: true});
|
|
this.endPacket();
|
|
}
|
|
},
|
|
// pong
|
|
'10': {
|
|
start: function(data) {
|
|
var self = this;
|
|
if (self.state.lastFragment == false) {
|
|
self.error('fragmented pong is not supported', 1002);
|
|
return;
|
|
}
|
|
|
|
// decode length
|
|
var firstLength = data[1] & 0x7f;
|
|
if (firstLength < 126) {
|
|
opcodes['10'].getData.call(self, firstLength);
|
|
}
|
|
else {
|
|
self.error('control frames cannot have more than 125 bytes of data', 1002);
|
|
}
|
|
},
|
|
getData: function(length) {
|
|
var self = this;
|
|
if (this.state.masked) {
|
|
this.expectHeader(4, function(data) {
|
|
var mask = data;
|
|
self.expectData(length, function(data) {
|
|
opcodes['10'].finish.call(self, mask, data);
|
|
});
|
|
});
|
|
}
|
|
else {
|
|
this.expectData(length, function(data) {
|
|
opcodes['10'].finish.call(self, null, data);
|
|
});
|
|
}
|
|
},
|
|
finish: function(mask, data) {
|
|
this.onpong(this.unmask(mask, data, true), {masked: this.state.masked, binary: true});
|
|
this.endPacket();
|
|
}
|
|
}
|
|
}
|