/*
* Copyright 2000-2015 JetBrains s.r.o.
*
* Licensed 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 com.intellij.util.containers;
import org.jetbrains.annotations.NotNull;
import java.lang.ref.ReferenceQueue;
import java.util.*;
abstract class RefKeyRefValueHashMap<K,V> implements Map<K,V>{
private final RefHashMap<K, ValueReference<K,V>> myWeakKeyMap;
private final ReferenceQueue<V> myQueue = new ReferenceQueue<V>();
public RefKeyRefValueHashMap(@NotNull RefHashMap<K, ValueReference<K, V>> weakKeyMap) {
myWeakKeyMap = weakKeyMap;
}
protected interface ValueReference<K, V> {
@NotNull
RefHashMap.Key<K> getKey();
V get();
}
protected V dereference(ValueReference<K, V> reference) {
return reference == null ? null : reference.get();
}
protected abstract ValueReference<K,V> createValueReference(@NotNull RefHashMap.Key<K> key, V referent, ReferenceQueue<? super V> q);
// returns true if some refs were tossed
boolean processQueue() {
boolean processed = myWeakKeyMap.processQueue();
while(true) {
ValueReference<K,V> ref = (ValueReference<K, V>)myQueue.poll();
if (ref == null) break;
RefHashMap.Key<K> weakKey = ref.getKey();
myWeakKeyMap.removeKey(weakKey);
processed = true;
}
return processed;
}
@Override
public V get(Object key) {
ValueReference<K,V> ref = myWeakKeyMap.get(key);
return dereference(ref);
}
@Override
public V put(K key, V value) {
processQueue();
RefHashMap.Key<K> weakKey = myWeakKeyMap.createKey(key);
ValueReference<K, V> reference = createValueReference(weakKey, value, myQueue);
ValueReference<K,V> oldRef = myWeakKeyMap.putKey(weakKey, reference);
return dereference(oldRef);
}
@Override
public V remove(Object key) {
processQueue();
ValueReference<K,V> ref = myWeakKeyMap.remove(key);
return dereference(ref);
}
@Override
public void putAll(@NotNull Map<? extends K, ? extends V> t) {
throw new RuntimeException("method not implemented");
}
@Override
public void clear() {
myWeakKeyMap.clear();
processQueue();
}
@Override
public int size() {
return myWeakKeyMap.size(); //?
}
@Override
public boolean isEmpty() {
return myWeakKeyMap.isEmpty(); //?
}
@Override
public boolean containsKey(Object key) {
return get(key) != null;
}
@Override
public boolean containsValue(Object value) {
throw new RuntimeException("method not implemented");
}
@NotNull
@Override
public Set<K> keySet() {
return myWeakKeyMap.keySet();
}
@NotNull
@Override
public Collection<V> values() {
List<V> result = new ArrayList<V>();
final Collection<ValueReference<K, V>> refs = myWeakKeyMap.values();
for (ValueReference<K, V> ref : refs) {
final V value = ref.get();
if (value != null) {
result.add(value);
}
}
return result;
}
@NotNull
@Override
public Set<Entry<K, V>> entrySet() {
throw new RuntimeException("method not implemented");
}
}