Mercurial > hg > truffle
comparison 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 |
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date | Wed, 13 Jun 2012 19:52:59 -0400 |
parents | |
children | cd6b3f1a94ff |
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6129:4d399f013e5a | 6162:e9140bf80b4a |
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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 |