/* Copyright 2012-2013 SpringSource.
 *
 * 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 grails.plugin.cache;

import java.util.Collection;
import java.util.Collections;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap;

import org.springframework.cache.Cache;

/**
 * Based on com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap.
 *
 * @author Jakob Drangmeister
 */
public class GrailsConcurrentLinkedMapCacheManager implements GrailsCacheManager {

   protected final ConcurrentMap<String, Cache> cacheMap = new ConcurrentHashMap<String, Cache>();

   public Collection<String> getCacheNames() {
      return Collections.unmodifiableSet(cacheMap.keySet());
   }

   public Cache getCache(String name) {
      return getCache(name, 10000);
   }

   public Cache getCache(String name, int capacity) {
      Cache cache = cacheMap.get(name);
      if (cache == null) {
         cache = createConcurrentLinkedMapCache(name, capacity);
         Cache existing = cacheMap.putIfAbsent(name, cache);
         if (existing != null) {
            cache = existing;
         }
      }
      return cache;
   }

   public boolean cacheExists(String name) {
      return getCacheNames().contains(name);
   }

   public boolean destroyCache(String name) {
      return cacheMap.remove(name) != null;
   }

   protected GrailsConcurrentLinkedMapCache createConcurrentLinkedMapCache(String name, long capacity) {
      return new GrailsConcurrentLinkedMapCache(name, capacity);
   }
}