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