Wed, 22 Jan 2014 17:42:23 -0800
Merge
kamg@4245 | 1 | /* |
kamg@4245 | 2 | * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved. |
kamg@4245 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
kamg@4245 | 4 | * |
kamg@4245 | 5 | * This code is free software; you can redistribute it and/or modify it |
kamg@4245 | 6 | * under the terms of the GNU General Public License version 2 only, as |
kamg@4245 | 7 | * published by the Free Software Foundation. |
kamg@4245 | 8 | * |
kamg@4245 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
kamg@4245 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
kamg@4245 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
kamg@4245 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
kamg@4245 | 13 | * accompanied this code). |
kamg@4245 | 14 | * |
kamg@4245 | 15 | * You should have received a copy of the GNU General Public License version |
kamg@4245 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
kamg@4245 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
kamg@4245 | 18 | * |
kamg@4245 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
kamg@4245 | 20 | * or visit www.oracle.com if you need additional information or have any |
kamg@4245 | 21 | * questions. |
kamg@4245 | 22 | * |
kamg@4245 | 23 | */ |
kamg@4245 | 24 | |
kamg@4245 | 25 | #ifndef SHARE_VM_UTILITIES_RESOURCEHASH_HPP |
kamg@4245 | 26 | #define SHARE_VM_UTILITIES_RESOURCEHASH_HPP |
kamg@4245 | 27 | |
kamg@4245 | 28 | #include "memory/allocation.hpp" |
kamg@4245 | 29 | #include "utilities/top.hpp" |
kamg@4245 | 30 | |
kamg@4245 | 31 | template<typename K> struct ResourceHashtableFns { |
kamg@4245 | 32 | typedef unsigned (*hash_fn)(K const&); |
kamg@4245 | 33 | typedef bool (*equals_fn)(K const&, K const&); |
kamg@4245 | 34 | }; |
kamg@4245 | 35 | |
kamg@4245 | 36 | template<typename K> unsigned primitive_hash(const K& k) { |
kamg@4245 | 37 | unsigned hash = (unsigned)((uintptr_t)k); |
kamg@4245 | 38 | return hash ^ (hash > 3); // just in case we're dealing with aligned ptrs |
kamg@4245 | 39 | } |
kamg@4245 | 40 | |
kamg@4245 | 41 | template<typename K> bool primitive_equals(const K& k0, const K& k1) { |
kamg@4245 | 42 | return k0 == k1; |
kamg@4245 | 43 | } |
kamg@4245 | 44 | |
kamg@4245 | 45 | template< |
kamg@4245 | 46 | typename K, typename V, |
goetz@6461 | 47 | // xlC does not compile this: |
goetz@6461 | 48 | // http://stackoverflow.com/questions/8532961/template-argument-of-type-that-is-defined-by-inner-typedef-from-other-template-c |
goetz@6461 | 49 | //typename ResourceHashtableFns<K>::hash_fn HASH = primitive_hash<K>, |
goetz@6461 | 50 | //typename ResourceHashtableFns<K>::equals_fn EQUALS = primitive_equals<K>, |
goetz@6461 | 51 | unsigned (*HASH) (K const&) = primitive_hash<K>, |
goetz@6461 | 52 | bool (*EQUALS)(K const&, K const&) = primitive_equals<K>, |
kamg@4245 | 53 | unsigned SIZE = 256 |
kamg@4245 | 54 | > |
kamg@4245 | 55 | class ResourceHashtable : public ResourceObj { |
kamg@4245 | 56 | private: |
kamg@4245 | 57 | |
kamg@4245 | 58 | class Node : public ResourceObj { |
kamg@4245 | 59 | public: |
kamg@4245 | 60 | unsigned _hash; |
kamg@4245 | 61 | K _key; |
kamg@4245 | 62 | V _value; |
kamg@4245 | 63 | Node* _next; |
kamg@4245 | 64 | |
kamg@4245 | 65 | Node(unsigned hash, K const& key, V const& value) : |
kamg@4245 | 66 | _hash(hash), _key(key), _value(value), _next(NULL) {} |
kamg@4245 | 67 | }; |
kamg@4245 | 68 | |
kamg@4245 | 69 | Node* _table[SIZE]; |
kamg@4245 | 70 | |
kamg@4245 | 71 | // Returns a pointer to where the node where the value would reside if |
kamg@4245 | 72 | // it's in the table. |
kamg@4245 | 73 | Node** lookup_node(unsigned hash, K const& key) { |
kamg@4245 | 74 | unsigned index = hash % SIZE; |
kamg@4245 | 75 | Node** ptr = &_table[index]; |
kamg@4245 | 76 | while (*ptr != NULL) { |
kamg@4245 | 77 | Node* node = *ptr; |
kamg@4245 | 78 | if (node->_hash == hash && EQUALS(key, node->_key)) { |
kamg@4245 | 79 | break; |
kamg@4245 | 80 | } |
kamg@4245 | 81 | ptr = &(node->_next); |
kamg@4245 | 82 | } |
kamg@4245 | 83 | return ptr; |
kamg@4245 | 84 | } |
kamg@4245 | 85 | |
kamg@4245 | 86 | Node const** lookup_node(unsigned hash, K const& key) const { |
kamg@4245 | 87 | return const_cast<Node const**>( |
kamg@4245 | 88 | const_cast<ResourceHashtable*>(this)->lookup_node(hash, key)); |
kamg@4245 | 89 | } |
kamg@4245 | 90 | |
kamg@4245 | 91 | public: |
kamg@4245 | 92 | ResourceHashtable() { memset(_table, 0, SIZE * sizeof(Node*)); } |
kamg@4245 | 93 | |
kamg@4245 | 94 | bool contains(K const& key) const { |
kamg@4245 | 95 | return get(key) != NULL; |
kamg@4245 | 96 | } |
kamg@4245 | 97 | |
kamg@4245 | 98 | V* get(K const& key) const { |
kamg@4245 | 99 | unsigned hv = HASH(key); |
kamg@4245 | 100 | Node const** ptr = lookup_node(hv, key); |
kamg@4245 | 101 | if (*ptr != NULL) { |
kamg@4245 | 102 | return const_cast<V*>(&(*ptr)->_value); |
kamg@4245 | 103 | } else { |
kamg@4245 | 104 | return NULL; |
kamg@4245 | 105 | } |
kamg@4245 | 106 | } |
kamg@4245 | 107 | |
kamg@4245 | 108 | // Inserts or replaces a value in the table |
kamg@4245 | 109 | void put(K const& key, V const& value) { |
kamg@4245 | 110 | unsigned hv = HASH(key); |
kamg@4245 | 111 | Node** ptr = lookup_node(hv, key); |
kamg@4245 | 112 | if (*ptr != NULL) { |
kamg@4245 | 113 | (*ptr)->_value = value; |
kamg@4245 | 114 | } else { |
kamg@4245 | 115 | *ptr = new Node(hv, key, value); |
kamg@4245 | 116 | } |
kamg@4245 | 117 | } |
kamg@4245 | 118 | |
kamg@4245 | 119 | // ITER contains bool do_entry(K const&, V const&), which will be |
kamg@4245 | 120 | // called for each entry in the table. If do_entry() returns false, |
kamg@4245 | 121 | // the iteration is cancelled. |
kamg@4245 | 122 | template<class ITER> |
kamg@4245 | 123 | void iterate(ITER* iter) const { |
kamg@4245 | 124 | Node* const* bucket = _table; |
kamg@4245 | 125 | while (bucket < &_table[SIZE]) { |
kamg@4245 | 126 | Node* node = *bucket; |
kamg@4245 | 127 | while (node != NULL) { |
kamg@4245 | 128 | bool cont = iter->do_entry(node->_key, node->_value); |
kamg@4245 | 129 | if (!cont) { return; } |
kamg@4245 | 130 | node = node->_next; |
kamg@4245 | 131 | } |
kamg@4245 | 132 | ++bucket; |
kamg@4245 | 133 | } |
kamg@4245 | 134 | } |
kamg@4245 | 135 | }; |
kamg@4245 | 136 | |
kamg@4245 | 137 | |
kamg@4245 | 138 | #endif // SHARE_VM_UTILITIES_RESOURCEHASH_HPP |