content: /**
   * This file is part of Aion-Lightning <aion-lightning.org>.
   *
   *  Aion-Lightning is free software: you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation, either version 3 of the License, or
   *  (at your option) any later version.
   *
   *  Aion-Lightning is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details. *
   *  You should have received a copy of the GNU General Public License
   *  along with Aion-Lightning.
   *  If not, see <http://www.gnu.org/licenses/>.
   */
  package com.aionemu.gameserver.utils.collections.cachemap;
  
  import java.lang.ref.Reference;
  import java.lang.ref.ReferenceQueue;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.slf4j.Logger;
  
  /**
   * Base class for {@link WeakCacheMap} and {@link SoftCacheMap}
   *
   * @param <K>
   * @param <V>
   * @author Luno
   */
  abstract class AbstractCacheMap<K, V> implements CacheMap<K, V> {
  
  	private final Logger log;
  	protected final String cacheName;
  	protected final String valueName;
  	/**
  	 * Map storing references to cached objects
  	 */
  	protected final Map<K, Reference<V>> cacheMap = new HashMap<K, Reference<V>>();
  	protected final ReferenceQueue<V> refQueue = new ReferenceQueue<V>();
  
  	/**
  	 * @param cacheName
  	 * @param valueName
  	 */
  	AbstractCacheMap(String cacheName, String valueName, Logger log) {
  		this.cacheName = "#CACHE  [" + cacheName + "]#  ";
  		this.valueName = valueName;
  		this.log = log;
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public void put(K key, V value) {
  		cleanQueue();
  
  		if (cacheMap.containsKey(key)) {
  			throw new IllegalArgumentException("Key: " + key + " already exists in map");
  		}
  
  		Reference<V> entry = newReference(key, value, refQueue);
  
  		cacheMap.put(key, entry);
  
  		if (log.isDebugEnabled()) {
  			log.debug(cacheName + " : added " + valueName + " for key: " + key);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public V get(K key) {
  		cleanQueue();
  
  		Reference<V> reference = cacheMap.get(key);
  
  		if (reference == null) {
  			return null;
  		}
  
  		V res = reference.get();
  
  		if (res != null && log.isDebugEnabled()) {
  			log.debug(cacheName + " : obtained " + valueName + " for key: " + key);
  		}
  
  		return res;
  	}
  
  	@Override
  	public boolean contains(K key) {
  		cleanQueue();
  		return cacheMap.containsKey(key);
  	}
  
  	protected abstract void cleanQueue();
  
  	@Override
  	public void remove(K key) {
  		cacheMap.remove(key);
  	}
  
  	protected abstract Reference<V> newReference(K key, V value, ReferenceQueue<V> queue);
  }
  