001/*
002 * PlotSquared, a land and world management plugin for Minecraft.
003 * Copyright (C) IntellectualSites <https://intellectualsites.com>
004 * Copyright (C) IntellectualSites team and contributors
005 *
006 * This program is free software: you can redistribute it and/or modify
007 * it under the terms of the GNU General Public License as published by
008 * the Free Software Foundation, either version 3 of the License, or
009 * (at your option) any later version.
010 *
011 * This program is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
014 * GNU General Public License for more details.
015 *
016 * You should have received a copy of the GNU General Public License
017 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
018 */
019package com.plotsquared.core.util;
020
021import org.checkerframework.checker.nullness.qual.NonNull;
022
023public final class HashUtil {
024
025    private HashUtil() {
026    }
027
028    /**
029     * Hashcode of a boolean array.<br>
030     * - Used for traversing mega plots quickly.
031     *
032     * @param array Booleans to hash
033     * @return hashcode
034     */
035    public static int hash(final @NonNull boolean[] array) {
036        if (array.length == 4) {
037            if (!array[0] && !array[1] && !array[2] && !array[3]) {
038                return 0;
039            }
040            return ((array[0] ? 1 : 0) << 3) + ((array[1] ? 1 : 0) << 2) + ((array[2] ? 1 : 0) << 1)
041                    + (array[3] ? 1 : 0);
042        }
043        int n = 0;
044        for (boolean anArray : array) {
045            n = (n << 1) + (anArray ? 1 : 0);
046        }
047        return n;
048    }
049
050}