websocket.js 5.9 KB

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  1. /**
  2. * Module dependencies.
  3. */
  4. var Transport = require('../transport');
  5. var parser = require('engine.io-parser');
  6. var parseqs = require('parseqs');
  7. var inherit = require('component-inherit');
  8. var yeast = require('yeast');
  9. var debug = require('debug')('engine.io-client:websocket');
  10. var BrowserWebSocket = global.WebSocket || global.MozWebSocket;
  11. /**
  12. * Get either the `WebSocket` or `MozWebSocket` globals
  13. * in the browser or try to resolve WebSocket-compatible
  14. * interface exposed by `ws` for Node-like environment.
  15. */
  16. var WebSocket = BrowserWebSocket;
  17. if (!WebSocket && typeof window === 'undefined') {
  18. try {
  19. WebSocket = require('ws');
  20. } catch (e) { }
  21. }
  22. /**
  23. * Module exports.
  24. */
  25. module.exports = WS;
  26. /**
  27. * WebSocket transport constructor.
  28. *
  29. * @api {Object} connection options
  30. * @api public
  31. */
  32. function WS(opts){
  33. var forceBase64 = (opts && opts.forceBase64);
  34. if (forceBase64) {
  35. this.supportsBinary = false;
  36. }
  37. this.perMessageDeflate = opts.perMessageDeflate;
  38. Transport.call(this, opts);
  39. }
  40. /**
  41. * Inherits from Transport.
  42. */
  43. inherit(WS, Transport);
  44. /**
  45. * Transport name.
  46. *
  47. * @api public
  48. */
  49. WS.prototype.name = 'websocket';
  50. /*
  51. * WebSockets support binary
  52. */
  53. WS.prototype.supportsBinary = true;
  54. /**
  55. * Opens socket.
  56. *
  57. * @api private
  58. */
  59. WS.prototype.doOpen = function(){
  60. if (!this.check()) {
  61. // let probe timeout
  62. return;
  63. }
  64. var self = this;
  65. var uri = this.uri();
  66. var protocols = void(0);
  67. var opts = {
  68. agent: this.agent,
  69. perMessageDeflate: this.perMessageDeflate
  70. };
  71. // SSL options for Node.js client
  72. opts.pfx = this.pfx;
  73. opts.key = this.key;
  74. opts.passphrase = this.passphrase;
  75. opts.cert = this.cert;
  76. opts.ca = this.ca;
  77. opts.ciphers = this.ciphers;
  78. opts.rejectUnauthorized = this.rejectUnauthorized;
  79. if (this.extraHeaders) {
  80. opts.headers = this.extraHeaders;
  81. }
  82. this.ws = BrowserWebSocket ? new WebSocket(uri) : new WebSocket(uri, protocols, opts);
  83. if (this.ws.binaryType === undefined) {
  84. this.supportsBinary = false;
  85. }
  86. if (this.ws.supports && this.ws.supports.binary) {
  87. this.supportsBinary = true;
  88. this.ws.binaryType = 'buffer';
  89. } else {
  90. this.ws.binaryType = 'arraybuffer';
  91. }
  92. this.addEventListeners();
  93. };
  94. /**
  95. * Adds event listeners to the socket
  96. *
  97. * @api private
  98. */
  99. WS.prototype.addEventListeners = function(){
  100. var self = this;
  101. this.ws.onopen = function(){
  102. self.onOpen();
  103. };
  104. this.ws.onclose = function(){
  105. self.onClose();
  106. };
  107. this.ws.onmessage = function(ev){
  108. self.onData(ev.data);
  109. };
  110. this.ws.onerror = function(e){
  111. self.onError('websocket error', e);
  112. };
  113. };
  114. /**
  115. * Override `onData` to use a timer on iOS.
  116. * See: https://gist.github.com/mloughran/2052006
  117. *
  118. * @api private
  119. */
  120. if ('undefined' != typeof navigator
  121. && /iPad|iPhone|iPod/i.test(navigator.userAgent)) {
  122. WS.prototype.onData = function(data){
  123. var self = this;
  124. setTimeout(function(){
  125. Transport.prototype.onData.call(self, data);
  126. }, 0);
  127. };
  128. }
  129. /**
  130. * Writes data to socket.
  131. *
  132. * @param {Array} array of packets.
  133. * @api private
  134. */
  135. WS.prototype.write = function(packets){
  136. var self = this;
  137. this.writable = false;
  138. // encodePacket efficient as it uses WS framing
  139. // no need for encodePayload
  140. var total = packets.length;
  141. for (var i = 0, l = total; i < l; i++) {
  142. (function(packet) {
  143. parser.encodePacket(packet, self.supportsBinary, function(data) {
  144. if (!BrowserWebSocket) {
  145. // always create a new object (GH-437)
  146. var opts = {};
  147. if (packet.options) {
  148. opts.compress = packet.options.compress;
  149. }
  150. if (self.perMessageDeflate) {
  151. var len = 'string' == typeof data ? global.Buffer.byteLength(data) : data.length;
  152. if (len < self.perMessageDeflate.threshold) {
  153. opts.compress = false;
  154. }
  155. }
  156. }
  157. //Sometimes the websocket has already been closed but the browser didn't
  158. //have a chance of informing us about it yet, in that case send will
  159. //throw an error
  160. try {
  161. if (BrowserWebSocket) {
  162. // TypeError is thrown when passing the second argument on Safari
  163. self.ws.send(data);
  164. } else {
  165. self.ws.send(data, opts);
  166. }
  167. } catch (e){
  168. debug('websocket closed before onclose event');
  169. }
  170. --total || done();
  171. });
  172. })(packets[i]);
  173. }
  174. function done(){
  175. self.emit('flush');
  176. // fake drain
  177. // defer to next tick to allow Socket to clear writeBuffer
  178. setTimeout(function(){
  179. self.writable = true;
  180. self.emit('drain');
  181. }, 0);
  182. }
  183. };
  184. /**
  185. * Called upon close
  186. *
  187. * @api private
  188. */
  189. WS.prototype.onClose = function(){
  190. Transport.prototype.onClose.call(this);
  191. };
  192. /**
  193. * Closes socket.
  194. *
  195. * @api private
  196. */
  197. WS.prototype.doClose = function(){
  198. if (typeof this.ws !== 'undefined') {
  199. this.ws.close();
  200. }
  201. };
  202. /**
  203. * Generates uri for connection.
  204. *
  205. * @api private
  206. */
  207. WS.prototype.uri = function(){
  208. var query = this.query || {};
  209. var schema = this.secure ? 'wss' : 'ws';
  210. var port = '';
  211. // avoid port if default for schema
  212. if (this.port && (('wss' == schema && this.port != 443)
  213. || ('ws' == schema && this.port != 80))) {
  214. port = ':' + this.port;
  215. }
  216. // append timestamp to URI
  217. if (this.timestampRequests) {
  218. query[this.timestampParam] = yeast();
  219. }
  220. // communicate binary support capabilities
  221. if (!this.supportsBinary) {
  222. query.b64 = 1;
  223. }
  224. query = parseqs.encode(query);
  225. // prepend ? to query
  226. if (query.length) {
  227. query = '?' + query;
  228. }
  229. var ipv6 = this.hostname.indexOf(':') !== -1;
  230. return schema + '://' + (ipv6 ? '[' + this.hostname + ']' : this.hostname) + port + this.path + query;
  231. };
  232. /**
  233. * Feature detection for WebSocket.
  234. *
  235. * @return {Boolean} whether this transport is available.
  236. * @api public
  237. */
  238. WS.prototype.check = function(){
  239. return !!WebSocket && !('__initialize' in WebSocket && this.name === WS.prototype.name);
  240. };