Showing the changes to java/pkg/sun/util/locale/LocaleObjectCache.java (1 of 18352 files). Show all
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| 1 | /* | ||
| 2 | * Copyright (c) 2010, 2011, 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle in the LICENSE file that accompanied this code. | ||
| 10 | * | ||
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | ||
| 14 | * version 2 for more details (a copy is included in the LICENSE file that | ||
| 15 | * accompanied this code). | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU General Public License version | ||
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, | ||
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | ||
| 20 | * | ||
| 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | /* | ||
| 27 | ******************************************************************************* | ||
| 28 | * Copyright (C) 2009-2010, International Business Machines Corporation and * | ||
| 29 | * others. All Rights Reserved. * | ||
| 30 | ******************************************************************************* | ||
| 31 | */ | ||
| 32 | package sun.util.locale; | ||
| 33 | |||
| 34 | import java.lang.ref.ReferenceQueue; | ||
| 35 | import java.lang.ref.SoftReference; | ||
| 36 | import java.util.concurrent.ConcurrentHashMap; | ||
| 37 | import java.util.concurrent.ConcurrentMap; | ||
| 38 | |||
| 39 | public abstract class LocaleObjectCache<K, V> { | ||
| 40 | private ConcurrentMap<K, CacheEntry<K, V>> map; | ||
| 41 | private ReferenceQueue<V> queue = new ReferenceQueue<>(); | ||
| 42 | |||
| 43 | public LocaleObjectCache() { | ||
| 44 | this(16, 0.75f, 16); | ||
| 45 | } | ||
| 46 | |||
| 47 | public LocaleObjectCache(int initialCapacity, float loadFactor, int concurrencyLevel) { | ||
| 48 | map = new ConcurrentHashMap<>(initialCapacity, loadFactor, concurrencyLevel); | ||
| 49 | } | ||
| 50 | |||
| 51 | public V get(K key) { | ||
| 52 | V value = null; | ||
| 53 | |||
| 54 | cleanStaleEntries(); | ||
| 55 | CacheEntry<K, V> entry = map.get(key); | ||
| 56 | if (entry != null) { | ||
| 57 | value = entry.get(); | ||
| 58 | } | ||
| 59 | if (value == null) { | ||
| 60 | key = normalizeKey(key); | ||
| 61 | V newVal = createObject(key); | ||
| 62 | if (key == null || newVal == null) { | ||
| 63 | // subclass must return non-null key/value object | ||
| 64 | return null; | ||
| 65 | } | ||
| 66 | |||
| 67 | CacheEntry<K, V> newEntry = new CacheEntry<>(key, newVal, queue); | ||
| 68 | |||
| 69 | while (value == null) { | ||
| 70 | cleanStaleEntries(); | ||
| 71 | entry = map.putIfAbsent(key, newEntry); | ||
| 72 | if (entry == null) { | ||
| 73 | value = newVal; | ||
| 74 | break; | ||
| 75 | } else { | ||
| 76 | value = entry.get(); | ||
| 77 | } | ||
| 78 | } | ||
| 79 | } | ||
| 80 | return value; | ||
| 81 | } | ||
| 82 | |||
| 83 | protected V put(K key, V value) { | ||
| 84 | CacheEntry<K, V> entry = new CacheEntry<>(key, value, queue); | ||
| 85 | CacheEntry<K, V> oldEntry = map.put(key, entry); | ||
| 86 | return (oldEntry == null) ? null : oldEntry.get(); | ||
| 87 | } | ||
| 88 | |||
| 89 | @SuppressWarnings("unchecked") | ||
| 90 | private void cleanStaleEntries() { | ||
| 91 | CacheEntry<K, V> entry; | ||
| 92 | while ((entry = (CacheEntry<K, V>)queue.poll()) != null) { | ||
| 93 | map.remove(entry.getKey()); | ||
| 94 | } | ||
| 95 | } | ||
| 96 | |||
| 97 | protected abstract V createObject(K key); | ||
| 98 | |||
| 99 | protected K normalizeKey(K key) { | ||
| 100 | return key; | ||
| 101 | } | ||
| 102 | |||
| 103 | private static class CacheEntry<K, V> extends SoftReference<V> { | ||
| 104 | private K key; | ||
| 105 | |||
| 106 | CacheEntry(K key, V value, ReferenceQueue<V> queue) { | ||
| 107 | super(value, queue); | ||
| 108 | this.key = key; | ||
| 109 | } | ||
| 110 | |||
| 111 | K getKey() { | ||
| 112 | return key; | ||
| 113 | } | ||
| 114 | } | ||
| 115 | } | ||