/*
 * JBoss, Home of Professional Open Source
 * Copyright 2009 Red Hat Inc. and/or its affiliates and other
 * contributors as indicated by the @author tags. All rights reserved.
 * See the copyright.txt in the distribution for a full listing of
 * individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.infinispan.loaders;

import org.infinispan.Cache;
import org.infinispan.container.entries.InternalCacheEntry;
import org.infinispan.marshall.StreamingMarshaller;

import java.util.Iterator;
import java.util.Set;

/**
 * An abstract {@link org.infinispan.loaders.CacheLoader} that holds common implementations for some methods
 *
 * @author Manik Surtani
 * @author Mircea.Markus@jboss.com
 * @since 4.0
 */
public abstract class AbstractCacheLoader implements CacheLoader {

   protected volatile StreamingMarshaller marshaller;
   protected volatile Cache<Object, Object> cache;

   /**
    * {@inheritDoc} This implementation delegates to {@link CacheLoader#load(Object)}, to ensure that a response is
    * returned only if the entry is not expired.
    */
   @Override
   public boolean containsKey(Object key) throws CacheLoaderException {
      return load(key) != null;
   }

   @Override
   public void init(CacheLoaderConfig config, Cache<?, ?> cache, StreamingMarshaller m) throws CacheLoaderException {
      this.marshaller = m;
      if (config == null) throw new IllegalStateException("Null config!!!");
      this.cache = (Cache<Object, Object>) cache;
   }

   @Override
   public boolean supportsLoadIterator() {
      //by default, not supported
      return false;
   }

   @Override
   public Iterator<Set<InternalCacheEntry>> loadAllIterator() throws CacheLoaderException {
      return null;
   }

   @Override
   public Iterator<Set<InternalCacheEntry>> loadSomeIterator(int maxEntries) throws CacheLoaderException {
      return null;
   }
}