| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.netbeans.modules.debugger.jpda.projects; |
| |
| import java.lang.ref.ReferenceQueue; |
| import java.lang.ref.WeakReference; |
| import java.util.AbstractMap; |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.Set; |
| import org.openide.util.BaseUtilities; |
| |
| /** |
| * A weak hash map, that automatically release entries as soon as they are freed by GC. |
| * |
| * @author Martin Entlicher |
| */ |
| // TODO: Make it a public API. There's another copy of this class in debugger.jpda module. |
| public final class WeakHashMapActive<K,V> extends AbstractMap<K,V> { |
| |
| private final ReferenceQueue<Object> queue; |
| private final Map<KeyReference<K>, V> map; |
| |
| public WeakHashMapActive() { |
| super(); |
| map = new HashMap<>(); |
| queue = BaseUtilities.activeReferenceQueue(); |
| } |
| |
| @Override |
| public V put(K key, V value) { |
| KeyReference<K> rk = new KeyReference<>(key, queue); |
| synchronized (map) { |
| return map.put(rk, value); |
| } |
| } |
| |
| @Override |
| public V get(Object key) { |
| KeyReference<Object> rk = new KeyReference<>(key, null); |
| synchronized (map) { |
| return map.get(rk); |
| } |
| } |
| |
| @Override |
| public V remove(Object key) { |
| KeyReference<Object> rk = new KeyReference<>(key, null); |
| synchronized (map) { |
| return map.remove(rk); |
| } |
| } |
| |
| @Override |
| public void clear() { |
| synchronized (map) { |
| map.clear(); |
| } |
| } |
| |
| @Override |
| public int size() { |
| synchronized (map) { |
| return map.size(); |
| } |
| } |
| |
| @Override |
| public Set<Entry<K, V>> entrySet() { |
| throw new UnsupportedOperationException("Not supported."); |
| } |
| |
| private class KeyReference<K> extends WeakReference<K> implements Runnable { |
| |
| private final int hash; |
| |
| KeyReference(K r, ReferenceQueue<? super K> queue) { |
| super(r, queue); |
| hash = r.hashCode(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return hash; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (!(obj instanceof KeyReference)) { |
| return false; |
| } |
| KeyReference kr = (KeyReference) obj; |
| K k1 = get(); |
| Object k2 = kr.get(); |
| if (k1 == null && k2 == null) { |
| return hash == kr.hash; |
| } |
| return (k1 == k2 || (k1 != null && k1.equals(k2))); |
| } |
| |
| @Override |
| public void run() { |
| // Collected |
| synchronized (map) { |
| map.remove(this); |
| } |
| } |
| |
| } |
| |
| } |