1   package org.apache.lucene.store.db;
    2   
    3   /**
    4    * Licensed to the Apache Software Foundation (ASF) under one or more
    5    * contributor license agreements.  See the NOTICE file distributed with
    6    * this work for additional information regarding copyright ownership.
    7    * The ASF licenses this file to You under the Apache License, Version 2.0
    8    * (the "License"); you may not use this file except in compliance with
    9    * the License.  You may obtain a copy of the License at
   10    *
   11    *     http://www.apache.org/licenses/LICENSE-2.0
   12    *
   13    * Unless required by applicable law or agreed to in writing, software
   14    * distributed under the License is distributed on an "AS IS" BASIS,
   15    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   16    * See the License for the specific language governing permissions and
   17    * limitations under the License.
   18    */
   19   
   20   import org.apache.lucene.store.Lock;
   21   
   22   /**
   23    * This implementation of {@link org.apache.lucene.store.Lock Lock} is
   24    * trivial as {@link DbDirectory} operations are managed by the Berkeley DB
   25    * locking system.
   26    *
   27    */
   28   
   29   public class DbLock extends Lock {
   30   
   31       boolean isLocked = false;
   32   
   33       public DbLock()
   34       {
   35       }
   36   
   37       @Override
   38       public boolean obtain()
   39       {
   40           return (isLocked = true);
   41       }
   42   
   43       @Override
   44       public void release()
   45       {
   46           isLocked = false;
   47       }
   48   
   49       @Override
   50       public boolean isLocked()
   51       {
   52           return isLocked;
   53       }
   54   }
   55