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