js-crc32/ctest/crc32.js

117 lines
3.4 KiB
JavaScript
Raw Normal View History

/* crc32.js (C) 2014-present SheetJS -- http://sheetjs.com */
2014-06-16 21:27:47 +00:00
/* vim: set ts=2: */
/*exported CRC32 */
2015-05-06 22:27:03 +00:00
var CRC32;
(function (factory) {
/*jshint ignore:start */
2015-05-06 22:27:03 +00:00
if(typeof DO_NOT_EXPORT_CRC === 'undefined') {
if('object' === typeof exports) {
factory(exports);
} else if ('function' === typeof define && define.amd) {
define(function () {
var module = {};
factory(module);
return module;
});
} else {
factory(CRC32 = {});
2015-05-06 22:27:03 +00:00
}
} else {
factory(CRC32 = {});
}
/*jshint ignore:end */
2015-05-06 22:27:03 +00:00
}(function(CRC32) {
CRC32.version = '1.0.0';
2014-06-16 21:27:47 +00:00
/* see perf/crc32table.js */
/*global Int32Array */
2014-06-16 21:27:47 +00:00
function signed_crc_table() {
2015-05-06 21:47:18 +00:00
var c = 0, table = new Array(256);
2014-06-16 21:27:47 +00:00
for(var n =0; n != 256; ++n){
c = n;
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
table[n] = c;
}
return typeof Int32Array !== 'undefined' ? new Int32Array(table) : table;
2014-06-16 21:27:47 +00:00
}
var T = signed_crc_table();
/*global Buffer */
var use_buffer = typeof Buffer !== 'undefined';
function crc32_bstr(bstr, seed) {
if(bstr.length > 32768) if(use_buffer) return crc32_buf_8(new Buffer(bstr), seed);
var C = seed ^ -1, L = bstr.length - 1;
for(var i = 0; i < L;) {
C = (C>>>8) ^ T[(C^bstr.charCodeAt(i++))&0xFF];
C = (C>>>8) ^ T[(C^bstr.charCodeAt(i++))&0xFF];
2014-06-16 21:27:47 +00:00
}
if(i === L) C = (C>>>8) ^ T[(C ^ bstr.charCodeAt(i))&0xFF];
return C ^ -1;
2014-06-16 21:27:47 +00:00
}
function crc32_buf(buf, seed) {
if(buf.length > 10000) return crc32_buf_8(buf, seed);
var C = seed ^ -1, L = buf.length - 3;
for(var i = 0; i < L;) {
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
2014-06-16 21:27:47 +00:00
}
while(i < L+3) C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
return C ^ -1;
2014-06-21 02:15:23 +00:00
}
function crc32_buf_8(buf, seed) {
var C = seed ^ -1, L = buf.length - 7;
for(var i = 0; i < L;) {
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
2014-06-21 02:15:23 +00:00
}
while(i < L+7) C = (C>>>8) ^ T[(C^buf[i++])&0xFF];
return C ^ -1;
2014-06-16 21:27:47 +00:00
}
function crc32_str(str, seed) {
var C = seed ^ -1;
for(var i = 0, L=str.length, c, d; i < L;) {
2014-06-16 21:27:47 +00:00
c = str.charCodeAt(i++);
if(c < 0x80) {
C = (C>>>8) ^ T[(C ^ c)&0xFF];
2014-06-16 21:27:47 +00:00
} else if(c < 0x800) {
C = (C>>>8) ^ T[(C ^ (192|((c>>6)&31)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|(c&63)))&0xFF];
2014-06-16 21:27:47 +00:00
} else if(c >= 0xD800 && c < 0xE000) {
c = (c&1023)+64; d = str.charCodeAt(i++)&1023;
C = (C>>>8) ^ T[(C ^ (240|((c>>8)&7)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|((c>>2)&63)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|((d>>6)&15)|((c&3)<<4)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|(d&63)))&0xFF];
2014-06-16 21:27:47 +00:00
} else {
C = (C>>>8) ^ T[(C ^ (224|((c>>12)&15)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|((c>>6)&63)))&0xFF];
C = (C>>>8) ^ T[(C ^ (128|(c&63)))&0xFF];
2014-06-16 21:27:47 +00:00
}
}
return C ^ -1;
2014-06-16 21:27:47 +00:00
}
CRC32.table = T;
2014-06-16 21:27:47 +00:00
CRC32.bstr = crc32_bstr;
CRC32.buf = crc32_buf;
CRC32.str = crc32_str;
2015-05-06 22:27:03 +00:00
}));