/*
* 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 com.intellij.util.ConcurrencyUtil;
import gnu.trove.TObjectHashingStrategy;
import org.jetbrains.annotations.NotNull;
import java.util.Set;
import java.util.concurrent.ConcurrentMap;
/**
* Allow to reuse structurally equal objects to avoid memory being wasted on them. Objects are cached on weak references
* and garbage-collected when not needed anymore.
*
* @author peter
*/
public class WeakInterner<T> {
private final ConcurrentMap<T, T> myMap;
public WeakInterner() {
myMap = ContainerUtil.createConcurrentWeakKeyWeakValueMap();
}
public WeakInterner(@NotNull TObjectHashingStrategy<T> strategy) {
myMap = ContainerUtil.createConcurrentWeakKeyWeakValueMap(strategy);
}
@NotNull
public T intern(@NotNull T name) {
return ConcurrencyUtil.cacheOrGet(myMap, name, name);
}
public void clear() {
myMap.clear();
}
@NotNull
public Set<T> getValues() {
return ContainerUtil.newTroveSet(myMap.values());
}
}