content: /*
   * 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.asterix.metadata.lock;
  
  import java.util.Objects;
  import java.util.concurrent.locks.ReentrantReadWriteLock;
  
  import org.apache.asterix.common.metadata.IMetadataLock;
  
  public class MetadataLock implements IMetadataLock {
      private final MetadataLockKey key;
      private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
  
      public MetadataLock(MetadataLockKey key) {
          this.key = Objects.requireNonNull(key);
      }
  
      @Override
      public void lock(IMetadataLock.Mode mode) {
          switch (mode) {
              case WRITE:
                  lock.writeLock().lock();
                  break;
              default:
                  lock.readLock().lock();
                  break;
          }
      }
  
      @Override
      public void unlock(IMetadataLock.Mode mode) {
          switch (mode) {
              case WRITE:
                  lock.writeLock().unlock();
                  break;
              default:
                  lock.readLock().unlock();
                  break;
          }
      }
  
      @Override
      public MetadataLockKey getKey() {
          return key;
      }
  
      @Override
      public int hashCode() {
          return key.hashCode();
      }
  
      @Override
      public boolean equals(Object o) {
          if (!(o instanceof MetadataLock)) {
              return false;
          }
          if (o == this) {
              return true;
          }
          return Objects.equals(key, ((MetadataLock) o).key);
      }
  
      @Override
      public String toString() {
          return String.valueOf(key);
      }
  }
  