|
6934
|
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_UTILITIES_RESOURCEHASH_HPP
|
|
|
26 #define SHARE_VM_UTILITIES_RESOURCEHASH_HPP
|
|
|
27
|
|
|
28 #include "memory/allocation.hpp"
|
|
|
29 #include "utilities/top.hpp"
|
|
|
30
|
|
|
31 template<typename K> struct ResourceHashtableFns {
|
|
|
32 typedef unsigned (*hash_fn)(K const&);
|
|
|
33 typedef bool (*equals_fn)(K const&, K const&);
|
|
|
34 };
|
|
|
35
|
|
|
36 template<typename K> unsigned primitive_hash(const K& k) {
|
|
|
37 unsigned hash = (unsigned)((uintptr_t)k);
|
|
|
38 return hash ^ (hash > 3); // just in case we're dealing with aligned ptrs
|
|
|
39 }
|
|
|
40
|
|
|
41 template<typename K> bool primitive_equals(const K& k0, const K& k1) {
|
|
|
42 return k0 == k1;
|
|
|
43 }
|
|
|
44
|
|
|
45 template<
|
|
|
46 typename K, typename V,
|
|
14411
|
47 // xlC does not compile this:
|
|
|
48 // http://stackoverflow.com/questions/8532961/template-argument-of-type-that-is-defined-by-inner-typedef-from-other-template-c
|
|
|
49 //typename ResourceHashtableFns<K>::hash_fn HASH = primitive_hash<K>,
|
|
|
50 //typename ResourceHashtableFns<K>::equals_fn EQUALS = primitive_equals<K>,
|
|
|
51 unsigned (*HASH) (K const&) = primitive_hash<K>,
|
|
|
52 bool (*EQUALS)(K const&, K const&) = primitive_equals<K>,
|
|
6934
|
53 unsigned SIZE = 256
|
|
|
54 >
|
|
|
55 class ResourceHashtable : public ResourceObj {
|
|
|
56 private:
|
|
|
57
|
|
|
58 class Node : public ResourceObj {
|
|
|
59 public:
|
|
|
60 unsigned _hash;
|
|
|
61 K _key;
|
|
|
62 V _value;
|
|
|
63 Node* _next;
|
|
|
64
|
|
|
65 Node(unsigned hash, K const& key, V const& value) :
|
|
|
66 _hash(hash), _key(key), _value(value), _next(NULL) {}
|
|
|
67 };
|
|
|
68
|
|
|
69 Node* _table[SIZE];
|
|
|
70
|
|
|
71 // Returns a pointer to where the node where the value would reside if
|
|
|
72 // it's in the table.
|
|
|
73 Node** lookup_node(unsigned hash, K const& key) {
|
|
|
74 unsigned index = hash % SIZE;
|
|
|
75 Node** ptr = &_table[index];
|
|
|
76 while (*ptr != NULL) {
|
|
|
77 Node* node = *ptr;
|
|
|
78 if (node->_hash == hash && EQUALS(key, node->_key)) {
|
|
|
79 break;
|
|
|
80 }
|
|
|
81 ptr = &(node->_next);
|
|
|
82 }
|
|
|
83 return ptr;
|
|
|
84 }
|
|
|
85
|
|
|
86 Node const** lookup_node(unsigned hash, K const& key) const {
|
|
|
87 return const_cast<Node const**>(
|
|
|
88 const_cast<ResourceHashtable*>(this)->lookup_node(hash, key));
|
|
|
89 }
|
|
|
90
|
|
|
91 public:
|
|
|
92 ResourceHashtable() { memset(_table, 0, SIZE * sizeof(Node*)); }
|
|
|
93
|
|
|
94 bool contains(K const& key) const {
|
|
|
95 return get(key) != NULL;
|
|
|
96 }
|
|
|
97
|
|
|
98 V* get(K const& key) const {
|
|
|
99 unsigned hv = HASH(key);
|
|
|
100 Node const** ptr = lookup_node(hv, key);
|
|
|
101 if (*ptr != NULL) {
|
|
|
102 return const_cast<V*>(&(*ptr)->_value);
|
|
|
103 } else {
|
|
|
104 return NULL;
|
|
|
105 }
|
|
|
106 }
|
|
|
107
|
|
|
108 // Inserts or replaces a value in the table
|
|
|
109 void put(K const& key, V const& value) {
|
|
|
110 unsigned hv = HASH(key);
|
|
|
111 Node** ptr = lookup_node(hv, key);
|
|
|
112 if (*ptr != NULL) {
|
|
|
113 (*ptr)->_value = value;
|
|
|
114 } else {
|
|
|
115 *ptr = new Node(hv, key, value);
|
|
|
116 }
|
|
|
117 }
|
|
|
118
|
|
|
119 // ITER contains bool do_entry(K const&, V const&), which will be
|
|
|
120 // called for each entry in the table. If do_entry() returns false,
|
|
|
121 // the iteration is cancelled.
|
|
|
122 template<class ITER>
|
|
|
123 void iterate(ITER* iter) const {
|
|
|
124 Node* const* bucket = _table;
|
|
|
125 while (bucket < &_table[SIZE]) {
|
|
|
126 Node* node = *bucket;
|
|
|
127 while (node != NULL) {
|
|
|
128 bool cont = iter->do_entry(node->_key, node->_value);
|
|
|
129 if (!cont) { return; }
|
|
|
130 node = node->_next;
|
|
|
131 }
|
|
|
132 ++bucket;
|
|
|
133 }
|
|
|
134 }
|
|
|
135 };
|
|
|
136
|
|
|
137
|
|
|
138 #endif // SHARE_VM_UTILITIES_RESOURCEHASH_HPP
|
