AlignmentStorage.java

/*
 * Copyright 2010
 * Ubiquitous Knowledge Processing (UKP) Lab
 * Technische Universität Darmstadt
 *
 * 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 de.tudarmstadt.ukp.dkpro.core.castransformation.internal;

import java.util.HashMap;
import java.util.Map;
import java.util.WeakHashMap;

import org.apache.uima.cas.CAS;

import de.tudarmstadt.ukp.dkpro.core.api.transform.alignment.AlignedString;
import de.tudarmstadt.ukp.dkpro.core.castransformation.ApplyChangesAnnotator;
import de.tudarmstadt.ukp.dkpro.core.castransformation.Backmapper;

/**
 * Use to smuggle the alignment state from the {@link ApplyChangesAnnotator} to the
 * {@link Backmapper}.
 *
 * @since 1.1.0
 */
public class AlignmentStorage
{
	private static AlignmentStorage instance;

	private Map<CAS, Map<Key, AlignedString>> mmap;

	{
		mmap = new WeakHashMap<CAS, Map<Key, AlignedString>>();
	}

	public static synchronized AlignmentStorage getInstance()
	{
		if (instance == null) {
			instance = new AlignmentStorage();
		}
		return instance;
	}

	public AlignedString get(final CAS aCas, final String from, final String to)
	{
		Map<Key, AlignedString> map = mmap.get(aCas);
		if (map == null) {
			return null;
		}
		return map.get(new Key(from, to));
	}

	public void put(final CAS aCas, final String from, final String to, final AlignedString aAs)
	{
		Map<Key, AlignedString> map = mmap.get(aCas);
		if (map == null) {
			map = new HashMap<Key, AlignedString>();
			mmap.put(aCas, map);
		}

		System.out.println("Adding from [" + from + "] to [" + to + "] on [" + aCas.hashCode()
				+ "]");
		map.put(new Key(from, to), aAs);
	}

	private static class Key
	{
		final String from;
		final String to;

		public Key(final String aFrom, final String aTo)
		{
			from = aFrom;
			to = aTo;
		}

		@Override
		public int hashCode()
		{
			final int prime = 31;
			int result = 1;
			result = prime * result + ((from == null) ? 0 : from.hashCode());
			result = prime * result + ((to == null) ? 0 : to.hashCode());
			return result;
		}

		@Override
		public boolean equals(Object obj)
		{
			if (this == obj) {
				return true;
			}
			if (obj == null) {
				return false;
			}
			if (getClass() != obj.getClass()) {
				return false;
			}
			Key other = (Key) obj;
			if (from == null) {
				if (other.from != null) {
					return false;
				}
			}
			else if (!from.equals(other.from)) {
				return false;
			}
			if (to == null) {
				if (other.to != null) {
					return false;
				}
			}
			else if (!to.equals(other.to)) {
				return false;
			}
			return true;
		}
	}
}