50 lines
1 KiB
JavaScript
50 lines
1 KiB
JavaScript
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/*
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MIT License http://www.opensource.org/licenses/mit-license.php
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Author Tobias Koppers @sokra
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*/
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"use strict";
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class StringXor {
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constructor() {
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this._value = undefined;
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this._buffer = undefined;
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}
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add(str) {
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let buf = this._buffer;
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let value;
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if (buf === undefined) {
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buf = this._buffer = Buffer.from(str, "latin1");
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this._value = Buffer.from(buf);
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return;
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} else if (buf.length !== str.length) {
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value = this._value;
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buf = this._buffer = Buffer.from(str, "latin1");
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if (value.length < buf.length) {
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this._value = Buffer.allocUnsafe(buf.length);
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value.copy(this._value);
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this._value.fill(0, value.length);
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value = this._value;
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}
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} else {
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value = this._value;
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buf.write(str, "latin1");
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}
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const len = buf.length;
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for (let i = 0; i < len; i++) {
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value[i] = value[i] ^ buf[i];
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}
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}
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toString() {
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return this._value === undefined ? "" : this._value.toString("latin1");
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}
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updateHash(hash) {
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if (this._value !== undefined) hash.update(this._value);
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}
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}
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module.exports = StringXor;
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