1 /* 2 * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package sun.misc; 26 27 import java.util.concurrent.ThreadLocalRandom; 28 29 /** 30 * Hashing utilities. 31 * 32 * Little endian implementations of Murmur3 hashing. 33 */ 34 public class Hashing { 35 36 /** 37 * Static utility methods only. 38 */ 39 private Hashing() { 40 throw new Error("No instances"); 41 } 42 43 // Spread bits to regularize both segment and index locations, 44 // using variant of single-word Wang/Jenkins hash. 45 // 46 // Based on commit 1424a2a1a9fc53dc8b859a77c02c924. 47 public static int singleWordWangJenkinsHash(Object k) { 48 int h = k.hashCode(); 49 50 h += (h << 15) ^ 0xffffcd7d; 51 h ^= (h >>> 10); 52 h += (h << 3); 53 h ^= (h >>> 6); 54 h += (h << 2) + (h << 14); 55 return h ^ (h >>> 16); 56 } 57 } 58
