source: trip-planner-front/node_modules/webpack/lib/util/StringXor.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Tobias Koppers @sokra
*/

"use strict";

class StringXor {
        constructor() {
                this._value = undefined;
                this._buffer = undefined;
        }

        add(str) {
                let buf = this._buffer;
                let value;
                if (buf === undefined) {
                        buf = this._buffer = Buffer.from(str, "latin1");
                        this._value = Buffer.from(buf);
                        return;
                } else if (buf.length !== str.length) {
                        value = this._value;
                        buf = this._buffer = Buffer.from(str, "latin1");
                        if (value.length < buf.length) {
                                this._value = Buffer.allocUnsafe(buf.length);
                                value.copy(this._value);
                                this._value.fill(0, value.length);
                                value = this._value;
                        }
                } else {
                        value = this._value;
                        buf.write(str, "latin1");
                }
                const len = buf.length;
                for (let i = 0; i < len; i++) {
                        value[i] = value[i] ^ buf[i];
                }
        }

        toString() {
                return this._value === undefined ? "" : this._value.toString("latin1");
        }

        updateHash(hash) {
                if (this._value !== undefined) hash.update(this._value);
        }
}

module.exports = StringXor;