IDGenerator.java

/*
 * 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.activemq.artemis.utils;

/**
 * Generator of record IDs for the journals.
 * <p>
 * Notice that while the bindings and messages journals are independent from one another they use
 * the same {@link IDGenerator} instance.
 * <p>
 * The next recordID should be persisted in the journals during a normal shutdown. The lack of such
 * a record indicates a server crash. During server restart, if the journals lack a
 * {@literal next-recordID} record, we use the last recorded ID plus {@code MAX_INT}.
 */
public interface IDGenerator {

   long generateID();

   long getCurrentID();
}