91 lines
2.4 KiB
JavaScript
91 lines
2.4 KiB
JavaScript
'use strict';
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Object.defineProperty(exports, '__esModule', { value: true });
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var math = require('./math-96d5e8c4.cjs');
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var buffer = require('./buffer-3e750729.cjs');
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require('./string-fddc5f8b.cjs');
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require('./array-78849c95.cjs');
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require('./set-5b47859e.cjs');
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require('./environment-1c97264d.cjs');
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require('./map-24d263c0.cjs');
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require('./conditions-f5c0c102.cjs');
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require('./storage.cjs');
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require('./function-314580f7.cjs');
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require('./object-c0c9435b.cjs');
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require('./equality.cjs');
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require('./encoding-1a745c43.cjs');
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require('./number-1fb57bba.cjs');
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require('./binary-ac8e39e2.cjs');
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require('./decoding-76e75827.cjs');
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require('./error-0c1f634f.cjs');
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/**
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* It is not recommended to use this package. This is the uncached implementation of the rabin
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* fingerprint algorithm. However, it can be used to verify the `rabin.js` implementation.
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*
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* @module rabin-uncached
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*/
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class RabinUncachedEncoder {
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/**
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* @param {Uint8Array} m assert(m[0] === 1)
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*/
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constructor (m) {
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this.m = m;
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this.blen = m.byteLength;
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this.bs = new Uint8Array(this.blen);
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/**
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* This describes the position of the most significant byte (starts with 0 and increases with
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* shift)
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*/
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this.bpos = 0;
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}
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/**
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* Add/Xor/Substract bytes.
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*
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* Discards bytes that are out of range.
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* @todo put this in function or inline
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*
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* @param {Uint8Array} cs
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*/
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add (cs) {
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const copyLen = math.min(this.blen, cs.byteLength);
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// copy from right to left until max is reached
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for (let i = 0; i < copyLen; i++) {
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this.bs[(this.bpos + this.blen - i - 1) % this.blen] ^= cs[cs.byteLength - i - 1];
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}
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}
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/**
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* @param {number} byte
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*/
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write (byte) {
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// [0,m1,m2,b]
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// x <- bpos
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// Shift one byte to the left, add b
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this.bs[this.bpos] = byte;
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this.bpos = (this.bpos + 1) % this.blen;
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// mod
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for (let i = 7; i >= 0; i--) {
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if (((this.bs[this.bpos] >>> i) & 1) === 1) {
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this.add(buffer.shiftNBitsLeft(this.m, i));
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}
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}
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// if (this.bs[this.bpos] !== 0) { error.unexpectedCase() }
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// assert(this.bs[this.bpos] === 0)
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}
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getFingerprint () {
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const result = new Uint8Array(this.blen - 1);
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for (let i = 0; i < result.byteLength; i++) {
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result[i] = this.bs[(this.bpos + i + 1) % this.blen];
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}
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return result
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}
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}
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exports.RabinUncachedEncoder = RabinUncachedEncoder;
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//# sourceMappingURL=rabin-uncached.cjs.map
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