binding-java/runtime/src/main/java/org/apache/etch/bindings/java/support/Class2TypeMap.java

/* $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.apache.etch.bindings.java.support;

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

import org.apache.etch.bindings.java.msg.Type;


/**
 * Mapping between Class and Type.
 */
public class Class2TypeMap
{
	/**
	 * @param c
	 * @return the Type for the specified class, or null.
	 */
	public Type get( Class<?> c )
	{
		return c2t.get( c );
	}

	/**
	 * Adds a map entry from c to t.
	 * @param c
	 * @param t
	 * @throws IllegalStateException if locked.
	 * @throws IllegalArgumentException if conflict.
	 */
	public void put( Class<?> c, Type t )
	{
		if (locked)
			throw new IllegalStateException( "locked" );
		
		Type x = c2t.get( c );
		if (x != null)
		{
			if (!x.equals( t ))
				throw new IllegalArgumentException( String.format(
					"type %s: class %s is already mapped to type %s",
					t, c, x ) );
			
			// x.equals( t ) therefore our work is finished.
			return;
		}
		
		c2t.put( c, t );
	}

	/**
	 * Adds all the mappings from other to this.
	 * @param other
	 * @throws IllegalStateException if locked.
	 * @throws IllegalArgumentException if conflict.
	 */
	public void addAll( Class2TypeMap other )
	{
		if (locked)
			throw new IllegalStateException( "locked" );
		
		for (Map.Entry<Class<?>, Type> me: other.c2t.entrySet())
			put( me.getKey(), me.getValue() );
	}

	/**
	 * Locks the map, disallowing any more changes.
	 */
	public void lock()
	{
		locked = true;
	}
	
	private final Map<Class<?>, Type> c2t = new HashMap<Class<?>, Type>();
	
	private boolean locked;
}