40 lines
1.5 KiB
JavaScript
40 lines
1.5 KiB
JavaScript
/* see perf/crc32table.js */
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/*global Int32Array */
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function signed_crc_table()/*:CRC32TableType*/ {
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var c = 0, table/*:Array<number>*/ = new Array(256);
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for(var n =0; n != 256; ++n){
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c = n;
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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c = ((c&1) ? (-306674912 ^ (c >>> 1)) : (c >>> 1));
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table[n] = c;
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}
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return typeof Int32Array !== 'undefined' ? new Int32Array(table) : table;
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}
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var T = signed_crc_table();
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/*# slice by 16 tables */
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function slice_by_16_tables(T) {
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var c = 0, v = 0, n = 0, table/*:Array<number>*/ = typeof Int32Array !== 'undefined' ? new Int32Array(4096) : new Array(4096) ;
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for(n = 0; n != 256; ++n) table[n] = T[n];
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for(n = 0; n != 256; ++n) {
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v = T[n];
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for(c = 256 + n; c < 4096; c += 256) v = table[c] = (v >>> 8) ^ T[v & 0xFF];
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}
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var out = [];
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for(n = 1; n != 16; ++n) out[n - 1] = typeof Int32Array !== 'undefined' ? table.subarray(n * 256, n * 256 + 256) : table.slice(n * 256, n * 256 + 256);
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return out;
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}
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var TT = slice_by_16_tables(T);
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var T1 = TT[0], T2 = TT[1], T3 = TT[2], T4 = TT[3], T5 = TT[4];
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var T6 = TT[5], T7 = TT[6], T8 = TT[7], T9 = TT[8], Ta = TT[9];
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var Tb = TT[10], Tc = TT[11], Td = TT[12], Te = TT[13], Tf = TT[14];
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