Mercurial > hg > truffle
annotate src/share/vm/utilities/resourceHash.hpp @ 21244:bf5e055dbc9c
SSAUtils: minor refactoring.
author | Josef Eisl <josef.eisl@jku.at> |
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date | Thu, 30 Apr 2015 15:36:03 +0200 |
parents | 52b4284cb496 |
children |
rev | line source |
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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, | |
18041
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
47 // xlC does not compile this: |
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
48 // http://stackoverflow.com/questions/8532961/template-argument-of-type-that-is-defined-by-inner-typedef-from-other-template-c |
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
49 //typename ResourceHashtableFns<K>::hash_fn HASH = primitive_hash<K>, |
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
50 //typename ResourceHashtableFns<K>::equals_fn EQUALS = primitive_equals<K>, |
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
51 unsigned (*HASH) (K const&) = primitive_hash<K>, |
52b4284cb496
Merge with jdk8u20-b26
Gilles Duboscq <duboscq@ssw.jku.at>
parents:
14909
diff
changeset
|
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 |