3 * ws: a node.js websocket client
4 * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
10 module.exports.BufferUtil = {
11 merge: function(mergedBuffer, buffers) {
13 for (var i = 0, l = buffers.length; i < l; ++i) {
15 buf.copy(mergedBuffer, offset);
19 mask: function(source, mask, output, offset, length) {
20 var maskNum = mask.readUInt32LE(0);
22 for (; i < length - 3; i += 4) {
23 var num = maskNum ^ source.readUInt32LE(i);
24 if (num < 0) { num = 4294967296 + num; }
25 output.writeUInt32LE(num, offset + i);
28 case 3: output[offset + i + 2] = source[i + 2] ^ mask[2];
29 case 2: output[offset + i + 1] = source[i + 1] ^ mask[1];
30 case 1: output[offset + i] = source[i] ^ mask[0];
34 unmask: function(data, mask) {
35 var maskNum = mask.readUInt32LE(0);
36 var length = data.length;
38 for (; i < length - 3; i += 4) {
39 var num = maskNum ^ data.readUInt32LE(i);
40 if (num < 0) { num = 4294967296 + num; }
41 data.writeUInt32LE(num, i);
44 case 3: data[i + 2] = data[i + 2] ^ mask[2];
45 case 2: data[i + 1] = data[i + 1] ^ mask[1];
46 case 1: data[i] = data[i] ^ mask[0];