Created
July 18, 2014 05:03
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A javascript CRC32. Original code from http://stackoverflow.com/questions/18638900/javascript-crc32 (and http://jsperf.com/js-crc32). Does not support UTF8
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var makeCRCTable = function(){ | |
var c; | |
var crcTable = []; | |
for(var n =0; n < 256; n++){ | |
c = n; | |
for(var k =0; k < 8; k++){ | |
c = ((c&1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1)); | |
} | |
crcTable[n] = c; | |
} | |
return crcTable; | |
} | |
var crc32 = function(str) { | |
var crcTable = window.crcTable || (window.crcTable = makeCRCTable()); | |
var crc = 0 ^ (-1); | |
for (var i = 0; i < str.length; i++ ) { | |
crc = (crc >>> 8) ^ crcTable[(crc ^ str.charCodeAt(i)) & 0xFF]; | |
} | |
return (crc ^ (-1)) >>> 0; | |
}; |
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