Mercurial > hg > truffle
diff src/share/vm/classfile/altHashing.hpp @ 6162:e9140bf80b4a
7158800: Improve storage of symbol tables
Summary: Use an alternate version of hashing algorithm for symbol string tables and after a certain bucket size to improve performance
Reviewed-by: pbk, kamg, dlong, kvn, fparain
author | coleenp |
---|---|
date | Wed, 13 Jun 2012 19:52:59 -0400 |
parents | |
children | cd6b3f1a94ff |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/classfile/altHashing.hpp Wed Jun 13 19:52:59 2012 -0400 @@ -0,0 +1,62 @@ +/* + * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_CLASSFILE_ALTHASHING_HPP +#define SHARE_VM_CLASSFILE_ALTHASHING_HPP + +#include "prims/jni.h" +#include "classfile/symbolTable.hpp" + +/** + * Hashing utilities. + * + * Implementation of Murmur3 hashing. + * This code was translated from src/share/classes/sun/misc/Hashing.java + * code in the JDK. + */ + +class AltHashing : AllStatic { + + // utility function copied from java/lang/Integer + static jint Integer_rotateLeft(jint i, int distance) { + return (i << distance) | (((juint)i) >> (32-distance)); + } + static jint murmur3_32(const int* data, int len); + static jint murmur3_32(jint seed, const int* data, int len); + +#ifndef PRODUCT + // Hashing functions used for internal testing + static jint murmur3_32(const jbyte* data, int len); + static jint murmur3_32(const jchar* data, int len); + static void testMurmur3_32_ByteArray(); + static void testEquivalentHashes(); +#endif // PRODUCT + + public: + static jint compute_seed(); + static jint murmur3_32(jint seed, const jbyte* data, int len); + static jint murmur3_32(jint seed, const jchar* data, int len); + NOT_PRODUCT(static void test_alt_hash();) +}; +#endif // SHARE_VM_CLASSFILE_ALTHASHING_HPP