2 * ws: a node.js websocket client
3 * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
7 module.exports.BufferUtil = {
8 merge: function(mergedBuffer, buffers) {
10 for (var i = 0, l = buffers.length; i < l; ++i) {
12 buf.copy(mergedBuffer, offset);
16 mask: function(source, mask, output, offset, length) {
17 var maskNum = mask.readUInt32LE(0, true);
19 for (; i < length - 3; i += 4) {
20 var num = maskNum ^ source.readUInt32LE(i, true);
21 if (num < 0) num = 4294967296 + num;
22 output.writeUInt32LE(num, offset + i, true);
25 case 3: output[offset + i + 2] = source[i + 2] ^ mask[2];
26 case 2: output[offset + i + 1] = source[i + 1] ^ mask[1];
27 case 1: output[offset + i] = source[i] ^ mask[0];
31 unmask: function(data, mask) {
32 var maskNum = mask.readUInt32LE(0, true);
33 var length = data.length;
35 for (; i < length - 3; i += 4) {
36 var num = maskNum ^ data.readUInt32LE(i, true);
37 if (num < 0) num = 4294967296 + num;
38 data.writeUInt32LE(num, i, true);
41 case 3: data[i + 2] = data[i + 2] ^ mask[2];
42 case 2: data[i + 1] = data[i + 1] ^ mask[1];
43 case 1: data[i] = data[i] ^ mask[0];