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/*
 * Copyright 2005-2014 Red Hat, Inc.
 * Red Hat 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.hornetq.utils;

/**
 * A SimpleIDGenerator
 *
 * @author Tim Fox
 *
 */
public class SimpleIDGenerator implements IDGenerator
{
   private long idSequence;

   private boolean wrapped;

   public SimpleIDGenerator(final long startID)
   {
      idSequence = startID;
   }

   public synchronized long generateID()
   {
      long id = idSequence++;

      if (idSequence == Long.MIN_VALUE)
      {
         wrapped = true;
      }

      if (wrapped)
      {
         // Wrap - Very unlikely to happen
         throw new IllegalStateException("Exhausted ids to use!");
      }

      return id;
   }

   public synchronized long getCurrentID()
   {
      return idSequence;
   }
}