106 lines
2.3 KiB
JavaScript
106 lines
2.3 KiB
JavaScript
/*!
|
|
* ws: a node.js websocket client
|
|
* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
|
|
* MIT Licensed
|
|
*/
|
|
|
|
/**
|
|
* Returns a Buffer from a "ff 00 ff"-type hex string.
|
|
*/
|
|
|
|
getBufferFromHexString = function(byteStr) {
|
|
var bytes = byteStr.split(' ');
|
|
var buf = new Buffer(bytes.length);
|
|
for (var i = 0; i < bytes.length; ++i) {
|
|
buf[i] = parseInt(bytes[i], 16);
|
|
}
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* Returns a hex string from a Buffer.
|
|
*/
|
|
|
|
getHexStringFromBuffer = function(data) {
|
|
var s = '';
|
|
for (var i = 0; i < data.length; ++i) {
|
|
s += padl(data[i].toString(16), 2, '0') + ' ';
|
|
}
|
|
return s.trim();
|
|
}
|
|
|
|
/**
|
|
* Splits a buffer in two parts.
|
|
*/
|
|
|
|
splitBuffer = function(buffer) {
|
|
var b1 = new Buffer(Math.ceil(buffer.length / 2));
|
|
buffer.copy(b1, 0, 0, b1.length);
|
|
var b2 = new Buffer(Math.floor(buffer.length / 2));
|
|
buffer.copy(b2, 0, b1.length, b1.length + b2.length);
|
|
return [b1, b2];
|
|
}
|
|
|
|
/**
|
|
* Performs hybi07+ type masking on a hex string or buffer.
|
|
*/
|
|
|
|
mask = function(buf, maskString) {
|
|
if (typeof buf == 'string') buf = new Buffer(buf);
|
|
var mask = getBufferFromHexString(maskString || '34 83 a8 68');
|
|
for (var i = 0; i < buf.length; ++i) {
|
|
buf[i] ^= mask[i % 4];
|
|
}
|
|
return buf;
|
|
}
|
|
|
|
/**
|
|
* Returns a hex string representing the length of a message
|
|
*/
|
|
|
|
getHybiLengthAsHexString = function(len, masked) {
|
|
if (len < 126) {
|
|
var buf = new Buffer(1);
|
|
buf[0] = (masked ? 0x80 : 0) | len;
|
|
}
|
|
else if (len < 65536) {
|
|
var buf = new Buffer(3);
|
|
buf[0] = (masked ? 0x80 : 0) | 126;
|
|
getBufferFromHexString(pack(4, len)).copy(buf, 1);
|
|
}
|
|
else {
|
|
var buf = new Buffer(9);
|
|
buf[0] = (masked ? 0x80 : 0) | 127;
|
|
getBufferFromHexString(pack(16, len)).copy(buf, 1);
|
|
}
|
|
return getHexStringFromBuffer(buf);
|
|
}
|
|
|
|
/**
|
|
* Unpacks a Buffer into a number.
|
|
*/
|
|
|
|
unpack = function(buffer) {
|
|
var n = 0;
|
|
for (var i = 0; i < buffer.length; ++i) {
|
|
n = (i == 0) ? buffer[i] : (n * 256) + buffer[i];
|
|
}
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* Returns a hex string, representing a specific byte count 'length', from a number.
|
|
*/
|
|
|
|
pack = function(length, number) {
|
|
return padl(number.toString(16), length, '0').replace(/([0-9a-f][0-9a-f])/gi, '$1 ').trim();
|
|
}
|
|
|
|
/**
|
|
* Left pads the string 's' to a total length of 'n' with char 'c'.
|
|
*/
|
|
|
|
padl = function(s, n, c) {
|
|
return new Array(1 + n - s.length).join(c) + s;
|
|
}
|