EmbargoFactory.java

/**
 * Copyright 2008 The University of North Carolina at Chapel Hill
 *
 * 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 edu.unc.lib.dl.security;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.fcrepo.server.errors.ObjectNotFoundException;

import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap.Builder;

import edu.unc.lib.dl.fedora.PID;
import edu.unc.lib.dl.util.TripleStoreQueryService;

/**
 * A factory for getting the list of ancestors for a pid. This will be implemented with a small cache.
 * 
 * @author count0
 * 
 */
public class EmbargoFactory {
	private final Map<PID, String> pid2Date;
	private boolean cacheValid = false;

	private TripleStoreQueryService tripleStoreQueryService = null;

	public EmbargoFactory() {
		Builder<PID, String> mapBuilder = new Builder<PID, String>();
		mapBuilder.maximumWeightedCapacity(10240);
		this.pid2Date = mapBuilder.build();
	}

	public TripleStoreQueryService getTripleStoreQueryService() {
		return tripleStoreQueryService;
	}

	public void setTripleStoreQueryService(TripleStoreQueryService tripleStoreQueryService) {
		this.tripleStoreQueryService = tripleStoreQueryService;
	}

	public List<String> getEmbargoDates(Set<PID> pids) throws ObjectNotFoundException {
		List<String> result = new ArrayList<String>();
		if (!cacheValid)
			updateCache();
		for (PID pid : pids) {
			String date = pid2Date.get(pid);
			if (date != null)
				result.add(date);
		}
		return result;
	}

	/**
	 * Call this method when any embargo triple is changed.
	 * 
	 * @param pid
	 */
	public void invalidate() {
		this.cacheValid = false;
	}

	private synchronized void updateCache() throws ObjectNotFoundException {
		this.pid2Date.clear();
		this.pid2Date.putAll(this.tripleStoreQueryService.fetchEmbargoes());
		this.cacheValid = true;
	}
}