DirtyOperationContext.java

/*
 * Copyright 2004-2009 the original author or authors.
 *
 * 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 org.compass.core.spi;

import java.util.HashSet;

import org.compass.core.marshall.MarshallingStrategy;
import org.elasticsearch.common.collect.IdentityHashSet;

/**
 * Context object for dirty (create/save/delete) operations.
 * 
 * @author kimchy
 */
public class DirtyOperationContext {

	private final IdentityHashSet<Object> operatedObjects = new IdentityHashSet<Object>();
	private final HashSet<ResourceKey> operatedKeys = new HashSet<ResourceKey>();

	private final MarshallingStrategy marshallingStrategy;

	public DirtyOperationContext() {
		this(null);
	}
	
	/**
	 * @param marshallingStrategy optional, allows tracking of objects by identity and resource key 
	 */
	public DirtyOperationContext(MarshallingStrategy marshallingStrategy) {
		this.marshallingStrategy = marshallingStrategy;
	}

	/**
	 * Adds the object as one that a dirty operation has been performed on.
	 * Note, the identity of the object is used.
	 */
	public void addOperatedObjects(Object obj) {
		if (!operatedObjects.contains(obj)) {
			operatedObjects.add(obj);

			ResourceKey key = toKey(obj);
			if (key != null) {
				operatedKeys.add(key);
			}
		}
	}

	/**
	 * Returns <code>true</code> if a dirty operation has been perfomed on the
	 * object (based on the object identity). <code>false</code> otherwise.
	 */
	public boolean alreadyPerformedOperation(Object obj) {
		if (operatedObjects.contains(obj)) {
			return true;
		} else {
			ResourceKey key = toKey(obj);
			return key == null ? false : operatedKeys.contains(key);
		}
	}

	private ResourceKey toKey(Object obj) {
		InternalResource resource = marshallingStrategy == null ? null : (InternalResource) marshallingStrategy.marshallIds(obj);
		return resource == null ? null : resource.getResourceKey();
	}
}