610 lines
14 KiB
JavaScript
610 lines
14 KiB
JavaScript
/**
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* Module dependencies.
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*/
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var keys = require('./keys');
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var hasBinary = require('has-binary');
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var sliceBuffer = require('arraybuffer.slice');
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var after = require('after');
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var utf8 = require('wtf-8');
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var base64encoder;
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if (global && global.ArrayBuffer) {
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base64encoder = require('base64-arraybuffer');
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}
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/**
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* Check if we are running an android browser. That requires us to use
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* ArrayBuffer with polling transports...
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*
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* http://ghinda.net/jpeg-blob-ajax-android/
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*/
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var isAndroid = typeof navigator !== 'undefined' && /Android/i.test(navigator.userAgent);
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/**
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* Check if we are running in PhantomJS.
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* Uploading a Blob with PhantomJS does not work correctly, as reported here:
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* https://github.com/ariya/phantomjs/issues/11395
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* @type boolean
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*/
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var isPhantomJS = typeof navigator !== 'undefined' && /PhantomJS/i.test(navigator.userAgent);
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/**
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* When true, avoids using Blobs to encode payloads.
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* @type boolean
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*/
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var dontSendBlobs = isAndroid || isPhantomJS;
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/**
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* Current protocol version.
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*/
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exports.protocol = 3;
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/**
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* Packet types.
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*/
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var packets = exports.packets = {
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open: 0 // non-ws
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, close: 1 // non-ws
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, ping: 2
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, pong: 3
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, message: 4
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, upgrade: 5
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, noop: 6
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};
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var packetslist = keys(packets);
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/**
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* Premade error packet.
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*/
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var err = { type: 'error', data: 'parser error' };
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/**
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* Create a blob api even for blob builder when vendor prefixes exist
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*/
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var Blob = require('blob');
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/**
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* Encodes a packet.
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*
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* <packet type id> [ <data> ]
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*
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* Example:
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*
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* 5hello world
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* 3
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* 4
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*
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* Binary is encoded in an identical principle
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*
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* @api private
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*/
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exports.encodePacket = function (packet, supportsBinary, utf8encode, callback) {
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if ('function' == typeof supportsBinary) {
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callback = supportsBinary;
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supportsBinary = false;
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}
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if ('function' == typeof utf8encode) {
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callback = utf8encode;
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utf8encode = null;
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}
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var data = (packet.data === undefined)
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? undefined
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: packet.data.buffer || packet.data;
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if (global.ArrayBuffer && data instanceof ArrayBuffer) {
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return encodeArrayBuffer(packet, supportsBinary, callback);
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} else if (Blob && data instanceof global.Blob) {
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return encodeBlob(packet, supportsBinary, callback);
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}
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// might be an object with { base64: true, data: dataAsBase64String }
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if (data && data.base64) {
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return encodeBase64Object(packet, callback);
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}
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// Sending data as a utf-8 string
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var encoded = packets[packet.type];
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// data fragment is optional
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if (undefined !== packet.data) {
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encoded += utf8encode ? utf8.encode(String(packet.data)) : String(packet.data);
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}
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return callback('' + encoded);
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};
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function encodeBase64Object(packet, callback) {
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// packet data is an object { base64: true, data: dataAsBase64String }
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var message = 'b' + exports.packets[packet.type] + packet.data.data;
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return callback(message);
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}
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/**
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* Encode packet helpers for binary types
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*/
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function encodeArrayBuffer(packet, supportsBinary, callback) {
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if (!supportsBinary) {
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return exports.encodeBase64Packet(packet, callback);
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}
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var data = packet.data;
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var contentArray = new Uint8Array(data);
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var resultBuffer = new Uint8Array(1 + data.byteLength);
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resultBuffer[0] = packets[packet.type];
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for (var i = 0; i < contentArray.length; i++) {
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resultBuffer[i+1] = contentArray[i];
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}
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return callback(resultBuffer.buffer);
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}
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function encodeBlobAsArrayBuffer(packet, supportsBinary, callback) {
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if (!supportsBinary) {
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return exports.encodeBase64Packet(packet, callback);
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}
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var fr = new FileReader();
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fr.onload = function() {
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packet.data = fr.result;
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exports.encodePacket(packet, supportsBinary, true, callback);
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};
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return fr.readAsArrayBuffer(packet.data);
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}
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function encodeBlob(packet, supportsBinary, callback) {
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if (!supportsBinary) {
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return exports.encodeBase64Packet(packet, callback);
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}
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if (dontSendBlobs) {
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return encodeBlobAsArrayBuffer(packet, supportsBinary, callback);
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}
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var length = new Uint8Array(1);
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length[0] = packets[packet.type];
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var blob = new Blob([length.buffer, packet.data]);
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return callback(blob);
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}
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/**
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* Encodes a packet with binary data in a base64 string
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*
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* @param {Object} packet, has `type` and `data`
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* @return {String} base64 encoded message
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*/
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exports.encodeBase64Packet = function(packet, callback) {
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var message = 'b' + exports.packets[packet.type];
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if (Blob && packet.data instanceof global.Blob) {
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var fr = new FileReader();
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fr.onload = function() {
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var b64 = fr.result.split(',')[1];
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callback(message + b64);
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};
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return fr.readAsDataURL(packet.data);
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}
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var b64data;
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try {
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b64data = String.fromCharCode.apply(null, new Uint8Array(packet.data));
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} catch (e) {
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// iPhone Safari doesn't let you apply with typed arrays
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var typed = new Uint8Array(packet.data);
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var basic = new Array(typed.length);
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for (var i = 0; i < typed.length; i++) {
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basic[i] = typed[i];
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}
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b64data = String.fromCharCode.apply(null, basic);
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}
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message += global.btoa(b64data);
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return callback(message);
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};
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/**
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* Decodes a packet. Changes format to Blob if requested.
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*
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* @return {Object} with `type` and `data` (if any)
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* @api private
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*/
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exports.decodePacket = function (data, binaryType, utf8decode) {
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if (data === undefined) {
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return err;
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}
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// String data
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if (typeof data == 'string') {
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if (data.charAt(0) == 'b') {
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return exports.decodeBase64Packet(data.substr(1), binaryType);
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}
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if (utf8decode) {
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data = tryDecode(data);
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if (data === false) {
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return err;
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}
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}
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var type = data.charAt(0);
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if (Number(type) != type || !packetslist[type]) {
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return err;
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}
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if (data.length > 1) {
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return { type: packetslist[type], data: data.substring(1) };
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} else {
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return { type: packetslist[type] };
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}
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}
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var asArray = new Uint8Array(data);
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var type = asArray[0];
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var rest = sliceBuffer(data, 1);
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if (Blob && binaryType === 'blob') {
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rest = new Blob([rest]);
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}
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return { type: packetslist[type], data: rest };
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};
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function tryDecode(data) {
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try {
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data = utf8.decode(data);
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} catch (e) {
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return false;
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}
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return data;
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}
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/**
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* Decodes a packet encoded in a base64 string
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*
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* @param {String} base64 encoded message
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* @return {Object} with `type` and `data` (if any)
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*/
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exports.decodeBase64Packet = function(msg, binaryType) {
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var type = packetslist[msg.charAt(0)];
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if (!base64encoder) {
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return { type: type, data: { base64: true, data: msg.substr(1) } };
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}
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var data = base64encoder.decode(msg.substr(1));
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if (binaryType === 'blob' && Blob) {
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data = new Blob([data]);
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}
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return { type: type, data: data };
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};
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/**
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* Encodes multiple messages (payload).
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*
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* <length>:data
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*
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* Example:
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*
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* 11:hello world2:hi
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*
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* If any contents are binary, they will be encoded as base64 strings. Base64
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* encoded strings are marked with a b before the length specifier
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*
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* @param {Array} packets
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* @api private
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*/
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exports.encodePayload = function (packets, supportsBinary, callback) {
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if (typeof supportsBinary == 'function') {
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callback = supportsBinary;
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supportsBinary = null;
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}
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var isBinary = hasBinary(packets);
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if (supportsBinary && isBinary) {
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if (Blob && !dontSendBlobs) {
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return exports.encodePayloadAsBlob(packets, callback);
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}
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return exports.encodePayloadAsArrayBuffer(packets, callback);
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}
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if (!packets.length) {
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return callback('0:');
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}
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function setLengthHeader(message) {
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return message.length + ':' + message;
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}
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function encodeOne(packet, doneCallback) {
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exports.encodePacket(packet, !isBinary ? false : supportsBinary, true, function(message) {
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doneCallback(null, setLengthHeader(message));
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});
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}
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map(packets, encodeOne, function(err, results) {
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return callback(results.join(''));
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});
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};
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/**
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* Async array map using after
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*/
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function map(ary, each, done) {
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var result = new Array(ary.length);
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var next = after(ary.length, done);
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var eachWithIndex = function(i, el, cb) {
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each(el, function(error, msg) {
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result[i] = msg;
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cb(error, result);
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});
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};
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for (var i = 0; i < ary.length; i++) {
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eachWithIndex(i, ary[i], next);
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}
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}
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/*
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* Decodes data when a payload is maybe expected. Possible binary contents are
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* decoded from their base64 representation
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*
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* @param {String} data, callback method
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* @api public
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*/
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exports.decodePayload = function (data, binaryType, callback) {
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if (typeof data != 'string') {
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return exports.decodePayloadAsBinary(data, binaryType, callback);
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}
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if (typeof binaryType === 'function') {
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callback = binaryType;
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binaryType = null;
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}
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var packet;
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if (data == '') {
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// parser error - ignoring payload
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return callback(err, 0, 1);
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}
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var length = ''
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, n, msg;
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for (var i = 0, l = data.length; i < l; i++) {
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var chr = data.charAt(i);
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if (':' != chr) {
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length += chr;
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} else {
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if ('' == length || (length != (n = Number(length)))) {
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// parser error - ignoring payload
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return callback(err, 0, 1);
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}
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msg = data.substr(i + 1, n);
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if (length != msg.length) {
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// parser error - ignoring payload
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return callback(err, 0, 1);
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}
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if (msg.length) {
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packet = exports.decodePacket(msg, binaryType, true);
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if (err.type == packet.type && err.data == packet.data) {
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// parser error in individual packet - ignoring payload
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return callback(err, 0, 1);
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}
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var ret = callback(packet, i + n, l);
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if (false === ret) return;
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}
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// advance cursor
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i += n;
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length = '';
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}
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}
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if (length != '') {
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// parser error - ignoring payload
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return callback(err, 0, 1);
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}
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};
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/**
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* Encodes multiple messages (payload) as binary.
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*
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* <1 = binary, 0 = string><number from 0-9><number from 0-9>[...]<number
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* 255><data>
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*
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* Example:
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* 1 3 255 1 2 3, if the binary contents are interpreted as 8 bit integers
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*
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* @param {Array} packets
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* @return {ArrayBuffer} encoded payload
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* @api private
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*/
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exports.encodePayloadAsArrayBuffer = function(packets, callback) {
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if (!packets.length) {
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return callback(new ArrayBuffer(0));
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}
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function encodeOne(packet, doneCallback) {
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exports.encodePacket(packet, true, true, function(data) {
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return doneCallback(null, data);
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});
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}
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map(packets, encodeOne, function(err, encodedPackets) {
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var totalLength = encodedPackets.reduce(function(acc, p) {
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var len;
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if (typeof p === 'string'){
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len = p.length;
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} else {
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len = p.byteLength;
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}
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return acc + len.toString().length + len + 2; // string/binary identifier + separator = 2
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}, 0);
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var resultArray = new Uint8Array(totalLength);
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var bufferIndex = 0;
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encodedPackets.forEach(function(p) {
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var isString = typeof p === 'string';
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var ab = p;
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if (isString) {
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var view = new Uint8Array(p.length);
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for (var i = 0; i < p.length; i++) {
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view[i] = p.charCodeAt(i);
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}
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ab = view.buffer;
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}
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if (isString) { // not true binary
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resultArray[bufferIndex++] = 0;
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} else { // true binary
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resultArray[bufferIndex++] = 1;
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}
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var lenStr = ab.byteLength.toString();
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for (var i = 0; i < lenStr.length; i++) {
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resultArray[bufferIndex++] = parseInt(lenStr[i]);
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}
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resultArray[bufferIndex++] = 255;
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var view = new Uint8Array(ab);
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for (var i = 0; i < view.length; i++) {
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resultArray[bufferIndex++] = view[i];
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}
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});
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return callback(resultArray.buffer);
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});
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};
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/**
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* Encode as Blob
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*/
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exports.encodePayloadAsBlob = function(packets, callback) {
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function encodeOne(packet, doneCallback) {
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exports.encodePacket(packet, true, true, function(encoded) {
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var binaryIdentifier = new Uint8Array(1);
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binaryIdentifier[0] = 1;
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if (typeof encoded === 'string') {
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var view = new Uint8Array(encoded.length);
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for (var i = 0; i < encoded.length; i++) {
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view[i] = encoded.charCodeAt(i);
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}
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encoded = view.buffer;
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binaryIdentifier[0] = 0;
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}
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var len = (encoded instanceof ArrayBuffer)
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? encoded.byteLength
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: encoded.size;
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var lenStr = len.toString();
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var lengthAry = new Uint8Array(lenStr.length + 1);
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for (var i = 0; i < lenStr.length; i++) {
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lengthAry[i] = parseInt(lenStr[i]);
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}
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lengthAry[lenStr.length] = 255;
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if (Blob) {
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var blob = new Blob([binaryIdentifier.buffer, lengthAry.buffer, encoded]);
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doneCallback(null, blob);
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}
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});
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}
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map(packets, encodeOne, function(err, results) {
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return callback(new Blob(results));
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});
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};
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/*
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* Decodes data when a payload is maybe expected. Strings are decoded by
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* interpreting each byte as a key code for entries marked to start with 0. See
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* description of encodePayloadAsBinary
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*
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* @param {ArrayBuffer} data, callback method
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* @api public
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*/
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exports.decodePayloadAsBinary = function (data, binaryType, callback) {
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if (typeof binaryType === 'function') {
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callback = binaryType;
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binaryType = null;
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}
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var bufferTail = data;
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var buffers = [];
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var numberTooLong = false;
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while (bufferTail.byteLength > 0) {
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var tailArray = new Uint8Array(bufferTail);
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var isString = tailArray[0] === 0;
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var msgLength = '';
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for (var i = 1; ; i++) {
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if (tailArray[i] == 255) break;
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if (msgLength.length > 310) {
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numberTooLong = true;
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break;
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}
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msgLength += tailArray[i];
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}
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if(numberTooLong) return callback(err, 0, 1);
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bufferTail = sliceBuffer(bufferTail, 2 + msgLength.length);
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msgLength = parseInt(msgLength);
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var msg = sliceBuffer(bufferTail, 0, msgLength);
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if (isString) {
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try {
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msg = String.fromCharCode.apply(null, new Uint8Array(msg));
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} catch (e) {
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// iPhone Safari doesn't let you apply to typed arrays
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var typed = new Uint8Array(msg);
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msg = '';
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|
for (var i = 0; i < typed.length; i++) {
|
|
msg += String.fromCharCode(typed[i]);
|
|
}
|
|
}
|
|
}
|
|
|
|
buffers.push(msg);
|
|
bufferTail = sliceBuffer(bufferTail, msgLength);
|
|
}
|
|
|
|
var total = buffers.length;
|
|
buffers.forEach(function(buffer, i) {
|
|
callback(exports.decodePacket(buffer, binaryType, true), i, total);
|
|
});
|
|
};
|