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'use strict';
var Buffer = require('safe-buffer').Buffer,
Emitter = require('events').EventEmitter,
util = require('util'),
streams = require('../streams'),
Headers = require('./headers'),
Reader = require('./stream_reader');
var Base = function(request, url, options) {
Emitter.call(this);
Base.validateOptions(options || {}, ['maxLength', 'masking', 'requireMasking', 'protocols']);
this._request = request;
this._reader = new Reader();
this._options = options || {};
this._maxLength = this._options.maxLength || this.MAX_LENGTH;
this._headers = new Headers();
this.__queue = [];
this.readyState = 0;
this.url = url;
this.io = new streams.IO(this);
this.messages = new streams.Messages(this);
this._bindEventListeners();
};
util.inherits(Base, Emitter);
Base.isWebSocket = function(request) {
var connection = request.headers.connection || '',
upgrade = request.headers.upgrade || '';
return request.method === 'GET' &&
connection.toLowerCase().split(/ *, */).indexOf('upgrade') >= 0 &&
upgrade.toLowerCase() === 'websocket';
};
Base.validateOptions = function(options, validKeys) {
for (var key in options) {
if (validKeys.indexOf(key) < 0)
throw new Error('Unrecognized option: ' + key);
}
};
var instance = {
// This is 64MB, small enough for an average VPS to handle without
// crashing from process out of memory
MAX_LENGTH: 0x3ffffff,
STATES: ['connecting', 'open', 'closing', 'closed'],
_bindEventListeners: function() {
var self = this;
// Protocol errors are informational and do not have to be handled
this.messages.on('error', function() {});
this.on('message', function(event) {
var messages = self.messages;
if (messages.readable) messages.emit('data', event.data);
});
this.on('error', function(error) {
var messages = self.messages;
if (messages.readable) messages.emit('error', error);
});
this.on('close', function() {
var messages = self.messages;
if (!messages.readable) return;
messages.readable = messages.writable = false;
messages.emit('end');
});
},
getState: function() {
return this.STATES[this.readyState] || null;
},
addExtension: function(extension) {
return false;
},
setHeader: function(name, value) {
if (this.readyState > 0) return false;
this._headers.set(name, value);
return true;
},
start: function() {
if (this.readyState !== 0) return false;
if (!Base.isWebSocket(this._request))
return this._failHandshake(new Error('Not a WebSocket request'));
var response;
try {
response = this._handshakeResponse();
} catch (error) {
return this._failHandshake(error);
}
this._write(response);
if (this._stage !== -1) this._open();
return true;
},
_failHandshake: function(error) {
var headers = new Headers();
headers.set('Content-Type', 'text/plain');
headers.set('Content-Length', Buffer.byteLength(error.message, 'utf8'));
headers = ['HTTP/1.1 400 Bad Request', headers.toString(), error.message];
this._write(Buffer.from(headers.join('\r\n'), 'utf8'));
this._fail('protocol_error', error.message);
return false;
},
text: function(message) {
return this.frame(message);
},
binary: function(message) {
return false;
},
ping: function() {
return false;
},
pong: function() {
return false;
},
close: function(reason, code) {
if (this.readyState !== 1) return false;
this.readyState = 3;
this.emit('close', new Base.CloseEvent(null, null));
return true;
},
_open: function() {
this.readyState = 1;
this.__queue.forEach(function(args) { this.frame.apply(this, args) }, this);
this.__queue = [];
this.emit('open', new Base.OpenEvent());
},
_queue: function(message) {
this.__queue.push(message);
return true;
},
_write: function(chunk) {
var io = this.io;
if (io.readable) io.emit('data', chunk);
},
_fail: function(type, message) {
this.readyState = 2;
this.emit('error', new Error(message));
this.close();
}
};
for (var key in instance)
Base.prototype[key] = instance[key];
Base.ConnectEvent = function() {};
Base.OpenEvent = function() {};
Base.CloseEvent = function(code, reason) {
this.code = code;
this.reason = reason;
};
Base.MessageEvent = function(data) {
this.data = data;
};
Base.PingEvent = function(data) {
this.data = data;
};
Base.PongEvent = function(data) {
this.data = data;
};
module.exports = Base;
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