1/*!
  2 * ws: a node.js websocket client
  3 * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
  4 * MIT Licensed
  5 */
  6
  7var events = require('events')
  8  , util = require('util')
  9  , EventEmitter = events.EventEmitter;
 10
 11/**
 12 * Hixie Sender implementation
 13 */
 14
 15function Sender(socket) {
 16  if (this instanceof Sender === false) {
 17    throw new TypeError("Classes can't be function-called");
 18  }
 19
 20  events.EventEmitter.call(this);
 21
 22  this.socket = socket;
 23  this.continuationFrame = false;
 24  this.isClosed = false;
 25}
 26
 27module.exports = Sender;
 28
 29/**
 30 * Inherits from EventEmitter.
 31 */
 32
 33util.inherits(Sender, events.EventEmitter);
 34
 35/**
 36 * Frames and writes data.
 37 *
 38 * @api public
 39 */
 40
 41Sender.prototype.send = function(data, options, cb) {
 42  if (this.isClosed) return;
 43
 44  var isString = typeof data == 'string'
 45    , length = isString ? Buffer.byteLength(data) : data.length
 46    , lengthbytes = (length > 127) ? 2 : 1 // assume less than 2**14 bytes
 47    , writeStartMarker = this.continuationFrame == false
 48    , writeEndMarker = !options || !(typeof options.fin != 'undefined' && !options.fin)
 49    , buffer = new Buffer((writeStartMarker ? ((options && options.binary) ? (1 + lengthbytes) : 1) : 0) + length + ((writeEndMarker && !(options && options.binary)) ? 1 : 0))
 50    , offset = writeStartMarker ? 1 : 0;
 51
 52  if (writeStartMarker) {
 53    if (options && options.binary) {
 54      buffer.write('\x80', 'binary');
 55      // assume length less than 2**14 bytes
 56      if (lengthbytes > 1)
 57        buffer.write(String.fromCharCode(128+length/128), offset++, 'binary');
 58      buffer.write(String.fromCharCode(length&0x7f), offset++, 'binary');
 59    } else
 60      buffer.write('\x00', 'binary');
 61  }
 62
 63  if (isString) buffer.write(data, offset, 'utf8');
 64  else data.copy(buffer, offset, 0);
 65
 66  if (writeEndMarker) {
 67    if (options && options.binary) {
 68      // sending binary, not writing end marker
 69    } else
 70      buffer.write('\xff', offset + length, 'binary');
 71    this.continuationFrame = false;
 72  }
 73  else this.continuationFrame = true;
 74
 75  try {
 76    this.socket.write(buffer, 'binary', cb);
 77  } catch (e) {
 78    this.error(e.toString());
 79  }
 80};
 81
 82/**
 83 * Sends a close instruction to the remote party.
 84 *
 85 * @api public
 86 */
 87
 88Sender.prototype.close = function(code, data, mask, cb) {
 89  if (this.isClosed) return;
 90  this.isClosed = true;
 91  try {
 92    if (this.continuationFrame) this.socket.write(new Buffer([0xff], 'binary'));
 93    this.socket.write(new Buffer([0xff, 0x00]), 'binary', cb);
 94  } catch (e) {
 95    this.error(e.toString());
 96  }
 97};
 98
 99/**
100 * Sends a ping message to the remote party. Not available for hixie.
101 *
102 * @api public
103 */
104
105Sender.prototype.ping = function(data, options) {};
106
107/**
108 * Sends a pong message to the remote party. Not available for hixie.
109 *
110 * @api public
111 */
112
113Sender.prototype.pong = function(data, options) {};
114
115/**
116 * Handles an error
117 *
118 * @api private
119 */
120
121Sender.prototype.error = function (reason) {
122  this.emit('error', reason);
123  return this;
124};