/*
 * 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.flink.configuration;

import org.apache.flink.annotation.Public;

import java.util.Properties;

/**
 * Unmodifiable version of the Configuration class.
 */
@Public
public class UnmodifiableConfiguration extends Configuration {
	
	private static final long serialVersionUID = -8151292629158972280L;

	/**
	 * Creates a new UnmodifiableConfiguration, which holds a copy of the given configuration
	 * that cannot be altered.
	 * 
	 * @param config The configuration with the original contents.
	 */
	public UnmodifiableConfiguration(Configuration config) {
		super(config);
	}

	// --------------------------------------------------------------------------------------------
	//  All mutating methods must fail
	// --------------------------------------------------------------------------------------------


	@Override
	public void addAllToProperties(Properties props) {
		// override to make the UnmodifiableConfigurationTest happy
		super.addAllToProperties(props);
	}

	@Override
	public final void addAll(Configuration other) {
		error();
	}

	@Override
	public final void addAll(Configuration other, String prefix) {
		error();
	}

	@Override
	final <T> void setValueInternal(String key, T value){
		error();
	}

	private void error(){
		throw new UnsupportedOperationException("The configuration is unmodifiable; its contents cannot be changed.");
	}
}
