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/*!
* ws: a node.js websocket client
* Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
* MIT Licensed
*/
module.exports.BufferUtil = {
merge: function(mergedBuffer, buffers) {
var offset = 0;
for (var i = 0, l = buffers.length; i < l; ++i) {
var buf = buffers[i];
buf.copy(mergedBuffer, offset);
offset += buf.length;
}
},
mask: function(source, mask, output, offset, length) {
var maskNum = mask.readUInt32LE(0, true);
var i = 0;
for (; i < length - 3; i += 4) {
var num = maskNum ^ source.readUInt32LE(i, true);
if (num < 0) num = 4294967296 + num;
output.writeUInt32LE(num, offset + i, true);
}
switch (length % 4) {
case 3: output[offset + i + 2] = source[i + 2] ^ mask[2];
case 2: output[offset + i + 1] = source[i + 1] ^ mask[1];
case 1: output[offset + i] = source[i] ^ mask[0];
case 0:;
}
},
unmask: function(data, mask) {
var maskNum = mask.readUInt32LE(0, true);
var length = data.length;
var i = 0;
for (; i < length - 3; i += 4) {
var num = maskNum ^ data.readUInt32LE(i, true);
if (num < 0) num = 4294967296 + num;
data.writeUInt32LE(num, i, true);
}
switch (length % 4) {
case 3: data[i + 2] = data[i + 2] ^ mask[2];
case 2: data[i + 1] = data[i + 1] ^ mask[1];
case 1: data[i] = data[i] ^ mask[0];
case 0:;
}
}
}
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