package org.apache.ojb.odmg.locking;

 /* Copyright 2002-2005 The Apache Software Foundation

  *

  * Licensed 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.

  */

 import java.util.Hashtable;

 class ObjectLocks

 {

     private LockEntry writer;

     private Hashtable readers;

     private long m_youngestReader = 0;

     public LockEntry getWriter()

     {

         return writer;

     }

     public void setWriter(LockEntry writer)

     {

         this.writer = writer;

     }

     public Hashtable getReaders()

     {

         return readers;

     }

     public void addReader(LockEntry reader)

     {

             /**

              * MBAIRD:

              * we want to track the youngest reader so we can remove all readers at timeout

              * if the youngestreader is older than the timeoutperiod.

              */

             if ((reader.getTimestamp() < m_youngestReader) || (m_youngestReader==0))

             {

                     m_youngestReader = reader.getTimestamp();

             }

         this.readers.put(reader.getTransactionId(), reader);

     }

         public long getYoungestReader()

         {

                 return m_youngestReader;

         }

     public LockEntry getReader(String transactionId)

     {

         return (LockEntry) this.readers.get(transactionId);

     }

     ObjectLocks()

     {

         writer = null;

         readers = new Hashtable();

     }

 }