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Added 'CRC-16 Checksum' operation

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This commit is contained in:
n1474335 2017-09-12 15:50:46 +00:00
parent 3c52a9faab
commit 174cabdc74
6 changed files with 30 additions and 31 deletions
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42
src/core/operations/Checksum.js
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@ -1,3 +1,4 @@
import * as CRC from "js-crc";
import Utils from "../Utils.js";
@ -119,19 +120,24 @@ const Checksum = {
/**
* CRC-32 Checksum operation.
*
* @param {byteArray} input
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
runCRC32: function(input, args) {
let crcTable = global.crcTable || (global.crcTable = Checksum._genCRCTable()),
crc = 0 ^ (-1);
return CRC.crc32(input);
},
for (let i = 0; i < input.length; i++) {
crc = (crc >>> 8) ^ crcTable[(crc ^ input[i]) & 0xff];
}
return Utils.hex((crc ^ (-1)) >>> 0);
/**
* CRC-16 Checksum operation.
*
* @param {string} input
* @param {Object[]} args
* @returns {string}
*/
runCRC16: function(input, args) {
return CRC.crc16(input);
},
@ -168,28 +174,6 @@ const Checksum = {
return Utils.hex(0xffff - csum);
},
/**
* Generates a CRC table for use with CRC checksums.
*
* @private
* @returns {array}
*/
_genCRCTable: function() {
let c,
crcTable = [];
for (let n = 0; n < 256; n++) {
c = n;
for (let k = 0; k < 8; k++) {
c = ((c & 1) ? (0xEDB88320 ^ (c >>> 1)) : (c >>> 1));
}
crcTable[n] = c;
}
return crcTable;
},
};
export default Checksum;