freemarker.cache.StrongCacheStorage Maven / Gradle / Ivy
/*
* 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 freemarker.cache;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* Strong cache storage is a cache storage that simply wraps a {@link Map}. It holds a strong reference to all objects
* it was passed, therefore prevents the cache from being purged during garbage collection. This class is always
* thread-safe since 2.3.24, before that if we are running on Java 5 or later.
*
* @see freemarker.template.Configuration#setCacheStorage(CacheStorage)
*/
public class StrongCacheStorage implements ConcurrentCacheStorage, CacheStorageWithGetSize {
private final Map map = new ConcurrentHashMap();
/**
* Always returns {@code true}.
*/
@Override
public boolean isConcurrent() {
return true;
}
@Override
public Object get(Object key) {
return map.get(key);
}
@Override
public void put(Object key, Object value) {
map.put(key, value);
}
@Override
public void remove(Object key) {
map.remove(key);
}
/**
* Returns a close approximation of the number of cache entries.
*
* @since 2.3.21
*/
@Override
public int getSize() {
return map.size();
}
@Override
public void clear() {
map.clear();
}
}