/**
 * 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.camel.processor.idempotent;

/**
 * Access to a repository of Message IDs to implement the
 * <a href="http://activemq.apache.org/camel/idempotent-consumer.html">Idempotent Consumer</a> pattern.
 *
 * @version $Revision: 35332 $
 */
public interface MessageIdRepository {

    /**
     * Returns true if this messageId has been processed before
     * otherwise this messageId is added to the repository and false is returned.
     *
     * @param messageId the String ID of the message
     * @return true if the message has been processed succesfully before otherwise false
     */
    boolean contains(String messageId);
}
