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"use strict";
// imported from https://github.com/socketio/engine.io-parser/tree/2.2.x
Object.defineProperty(exports, "__esModule", { value: true });
exports.decodePayloadAsBinary = exports.encodePayloadAsBinary = exports.decodePayload = exports.encodePayload = exports.decodeBase64Packet = exports.decodePacket = exports.encodeBase64Packet = exports.encodePacket = exports.packets = exports.protocol = void 0;
/**
* Module dependencies.
*/
var utf8 = require('./utf8');
/**
* Current protocol version.
*/
exports.protocol = 3;
const hasBinary = (packets) => {
for (const packet of packets) {
if (packet.data instanceof ArrayBuffer || ArrayBuffer.isView(packet.data)) {
return true;
}
}
return false;
};
/**
* Packet types.
*/
exports.packets = {
open: 0 // non-ws
,
close: 1 // non-ws
,
ping: 2,
pong: 3,
message: 4,
upgrade: 5,
noop: 6
};
var packetslist = Object.keys(exports.packets);
/**
* Premade error packet.
*/
var err = { type: 'error', data: 'parser error' };
const EMPTY_BUFFER = Buffer.concat([]);
/**
* Encodes a packet.
*
* <packet type id> [ <data> ]
*
* Example:
*
* 5hello world
* 3
* 4
*
* Binary is encoded in an identical principle
*
* @api private
*/
function encodePacket(packet, supportsBinary, utf8encode, callback) {
if (typeof supportsBinary === 'function') {
callback = supportsBinary;
supportsBinary = null;
}
if (typeof utf8encode === 'function') {
callback = utf8encode;
utf8encode = null;
}
if (Buffer.isBuffer(packet.data)) {
return encodeBuffer(packet, supportsBinary, callback);
}
else if (packet.data && (packet.data.buffer || packet.data) instanceof ArrayBuffer) {
return encodeBuffer({ type: packet.type, data: arrayBufferToBuffer(packet.data) }, supportsBinary, callback);
}
// Sending data as a utf-8 string
var encoded = exports.packets[packet.type];
// data fragment is optional
if (undefined !== packet.data) {
encoded += utf8encode ? utf8.encode(String(packet.data), { strict: false }) : String(packet.data);
}
return callback('' + encoded);
}
exports.encodePacket = encodePacket;
;
/**
* Encode Buffer data
*/
function encodeBuffer(packet, supportsBinary, callback) {
if (!supportsBinary) {
return encodeBase64Packet(packet, callback);
}
var data = packet.data;
var typeBuffer = Buffer.allocUnsafe(1);
typeBuffer[0] = exports.packets[packet.type];
return callback(Buffer.concat([typeBuffer, data]));
}
/**
* Encodes a packet with binary data in a base64 string
*
* @param {Object} packet, has `type` and `data`
* @return {String} base64 encoded message
*/
function encodeBase64Packet(packet, callback) {
var data = Buffer.isBuffer(packet.data) ? packet.data : arrayBufferToBuffer(packet.data);
var message = 'b' + exports.packets[packet.type];
message += data.toString('base64');
return callback(message);
}
exports.encodeBase64Packet = encodeBase64Packet;
;
/**
* Decodes a packet. Data also available as an ArrayBuffer if requested.
*
* @return {Object} with `type` and `data` (if any)
* @api private
*/
function decodePacket(data, binaryType, utf8decode) {
if (data === undefined) {
return err;
}
var type;
// String data
if (typeof data === 'string') {
type = data.charAt(0);
if (type === 'b') {
return decodeBase64Packet(data.slice(1), binaryType);
}
if (utf8decode) {
data = tryDecode(data);
if (data === false) {
return err;
}
}
if (Number(type) != type || !packetslist[type]) {
return err;
}
if (data.length > 1) {
return { type: packetslist[type], data: data.slice(1) };
}
else {
return { type: packetslist[type] };
}
}
// Binary data
if (binaryType === 'arraybuffer') {
// wrap Buffer/ArrayBuffer data into an Uint8Array
var intArray = new Uint8Array(data);
type = intArray[0];
return { type: packetslist[type], data: intArray.buffer.slice(1) };
}
if (data instanceof ArrayBuffer) {
data = arrayBufferToBuffer(data);
}
type = data[0];
return { type: packetslist[type], data: data.slice(1) };
}
exports.decodePacket = decodePacket;
;
function tryDecode(data) {
try {
data = utf8.decode(data, { strict: false });
}
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)
*/
function decodeBase64Packet(msg, binaryType) {
var type = packetslist[msg.charAt(0)];
var data = Buffer.from(msg.slice(1), 'base64');
if (binaryType === 'arraybuffer') {
var abv = new Uint8Array(data.length);
for (var i = 0; i < abv.length; i++) {
abv[i] = data[i];
}
// @ts-ignore
data = abv.buffer;
}
return { type: type, data: data };
}
exports.decodeBase64Packet = decodeBase64Packet;
;
/**
* 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
*/
function encodePayload(packets, supportsBinary, callback) {
if (typeof supportsBinary === 'function') {
callback = supportsBinary;
supportsBinary = null;
}
if (supportsBinary && hasBinary(packets)) {
return encodePayloadAsBinary(packets, callback);
}
if (!packets.length) {
return callback('0:');
}
function encodeOne(packet, doneCallback) {
encodePacket(packet, supportsBinary, false, function (message) {
doneCallback(null, setLengthHeader(message));
});
}
map(packets, encodeOne, function (err, results) {
return callback(results.join(''));
});
}
exports.encodePayload = encodePayload;
;
function setLengthHeader(message) {
return message.length + ':' + message;
}
/**
* Async array map using after
*/
function map(ary, each, done) {
const results = new Array(ary.length);
let count = 0;
for (let i = 0; i < ary.length; i++) {
each(ary[i], (error, msg) => {
results[i] = msg;
if (++count === ary.length) {
done(null, results);
}
});
}
}
/*
* Decodes data when a payload is maybe expected. Possible binary contents are
* decoded from their base64 representation
*
* @param {String} data, callback method
* @api public
*/
function decodePayload(data, binaryType, callback) {
if (typeof data !== 'string') {
return decodePayloadAsBinary(data, binaryType, callback);
}
if (typeof binaryType === 'function') {
callback = binaryType;
binaryType = null;
}
if (data === '') {
// parser error - ignoring payload
return callback(err, 0, 1);
}
var length = '', n, msg, packet;
for (var i = 0, l = data.length; i < l; i++) {
var chr = data.charAt(i);
if (chr !== ':') {
length += chr;
continue;
}
// @ts-ignore
if (length === '' || (length != (n = Number(length)))) {
// parser error - ignoring payload
return callback(err, 0, 1);
}
msg = data.slice(i + 1, i + 1 + n);
if (length != msg.length) {
// parser error - ignoring payload
return callback(err, 0, 1);
}
if (msg.length) {
packet = decodePacket(msg, binaryType, false);
if (err.type === packet.type && err.data === packet.data) {
// parser error in individual packet - ignoring payload
return callback(err, 0, 1);
}
var more = callback(packet, i + n, l);
if (false === more)
return;
}
// advance cursor
i += n;
length = '';
}
if (length !== '') {
// parser error - ignoring payload
return callback(err, 0, 1);
}
}
exports.decodePayload = decodePayload;
;
/**
*
* Converts a buffer to a utf8.js encoded string
*
* @api private
*/
function bufferToString(buffer) {
var str = '';
for (var i = 0, l = buffer.length; i < l; i++) {
str += String.fromCharCode(buffer[i]);
}
return str;
}
/**
*
* Converts a utf8.js encoded string to a buffer
*
* @api private
*/
function stringToBuffer(string) {
var buf = Buffer.allocUnsafe(string.length);
for (var i = 0, l = string.length; i < l; i++) {
buf.writeUInt8(string.charCodeAt(i), i);
}
return buf;
}
/**
*
* Converts an ArrayBuffer to a Buffer
*
* @api private
*/
function arrayBufferToBuffer(data) {
// data is either an ArrayBuffer or ArrayBufferView.
var length = data.byteLength || data.length;
var offset = data.byteOffset || 0;
return Buffer.from(data.buffer || data, offset, length);
}
/**
* 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 {Buffer} encoded payload
* @api private
*/
function encodePayloadAsBinary(packets, callback) {
if (!packets.length) {
return callback(EMPTY_BUFFER);
}
map(packets, encodeOneBinaryPacket, function (err, results) {
return callback(Buffer.concat(results));
});
}
exports.encodePayloadAsBinary = encodePayloadAsBinary;
;
function encodeOneBinaryPacket(p, doneCallback) {
function onBinaryPacketEncode(packet) {
var encodingLength = '' + packet.length;
var sizeBuffer;
if (typeof packet === 'string') {
sizeBuffer = Buffer.allocUnsafe(encodingLength.length + 2);
sizeBuffer[0] = 0; // is a string (not true binary = 0)
for (var i = 0; i < encodingLength.length; i++) {
sizeBuffer[i + 1] = parseInt(encodingLength[i], 10);
}
sizeBuffer[sizeBuffer.length - 1] = 255;
return doneCallback(null, Buffer.concat([sizeBuffer, stringToBuffer(packet)]));
}
sizeBuffer = Buffer.allocUnsafe(encodingLength.length + 2);
sizeBuffer[0] = 1; // is binary (true binary = 1)
for (var i = 0; i < encodingLength.length; i++) {
sizeBuffer[i + 1] = parseInt(encodingLength[i], 10);
}
sizeBuffer[sizeBuffer.length - 1] = 255;
doneCallback(null, Buffer.concat([sizeBuffer, packet]));
}
encodePacket(p, true, true, onBinaryPacketEncode);
}
/*
* 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 {Buffer} data, callback method
* @api public
*/
function decodePayloadAsBinary(data, binaryType, callback) {
if (typeof binaryType === 'function') {
callback = binaryType;
binaryType = null;
}
var bufferTail = data;
var buffers = [];
var i;
while (bufferTail.length > 0) {
var strLen = '';
var isString = bufferTail[0] === 0;
for (i = 1;; i++) {
if (bufferTail[i] === 255)
break;
// 310 = char length of Number.MAX_VALUE
if (strLen.length > 310) {
return callback(err, 0, 1);
}
strLen += '' + bufferTail[i];
}
bufferTail = bufferTail.slice(strLen.length + 1);
var msgLength = parseInt(strLen, 10);
var msg = bufferTail.slice(1, msgLength + 1);
if (isString)
msg = bufferToString(msg);
buffers.push(msg);
bufferTail = bufferTail.slice(msgLength + 1);
}
var total = buffers.length;
for (i = 0; i < total; i++) {
var buffer = buffers[i];
callback(decodePacket(buffer, binaryType, true), i, total);
}
}
exports.decodePayloadAsBinary = decodePayloadAsBinary;
;