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