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.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef SHARE_VM_CLASSFILE_ALTHASHING_HPP

    26 #define SHARE_VM_CLASSFILE_ALTHASHING_HPP

    27 

    28 #include "prims/jni.h"

    29 #include "classfile/symbolTable.hpp"

    30 

    31 /**

    32  * Hashing utilities.

    33  *

    34  * Implementation of Murmur3 hashing.

    35  * This code was translated from src/share/classes/sun/misc/Hashing.java

    36  * code in the JDK.

    37  */

    38 

    39 class AltHashing : AllStatic {

    40 

    41   // utility function copied from java/lang/Integer

    42   static jint Integer_rotateLeft(jint i, int distance) {

    43     return (i << distance) | (((juint)i) >> (32-distance));

    44   }

    45   static jint murmur3_32(const int* data, int len);

    46   static jint murmur3_32(jint seed, const int* data, int len);

    47 

    48 #ifndef PRODUCT

    49   // Hashing functions used for internal testing

    50   static jint murmur3_32(const jbyte* data, int len);

    51   static jint murmur3_32(const jchar* data, int len);

    52   static void testMurmur3_32_ByteArray();

    53   static void testEquivalentHashes();

    54 #endif // PRODUCT

    55 

    56  public:

    57   static jint compute_seed();

    58   static jint murmur3_32(jint seed, const jbyte* data, int len);

    59   static jint murmur3_32(jint seed, const jchar* data, int len);

    60   NOT_PRODUCT(static void test_alt_hash();)

    61 };

    62 #endif // SHARE_VM_CLASSFILE_ALTHASHING_HPP