content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.worker.block.io;
  
  import com.google.common.base.MoreObjects;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * Provides basic tracking and representation for block reader/writer clients.
   */
  public abstract class BlockClient implements Closeable {
    private static final Logger LOG = LoggerFactory.getLogger(BlockClient.class);
  
    /** Used to keep unique client ids. */
    private static final AtomicInteger NEXT_CLIENT_ID = new AtomicInteger(0);
  
    /** Internal client id. */
    private final int mClientId;
    /** the client type. */
    private final Type mClientType;
  
    /**
     * Creates an abstract block reader/writer.
     *
     * @param clientType the block client type
     */
    public BlockClient(Type clientType) {
      mClientId = NEXT_CLIENT_ID.getAndIncrement();
      mClientType = clientType;
      LOG.debug("BlockClient created: {}.", this);
    }
  
    @Override
    public String toString() {
      return MoreObjects.toStringHelper(this)
          .add("Id", mClientId)
          .add("Type", mClientType.name())
          .add("Class", getClass().getName())
          .toString();
    }
  
    @Override
    public void close() throws IOException {
      LOG.debug("BlockClient closed: {}.", this);
    }
  
    /**
     * Block client type.
     */
    public enum Type {
      READER, WRITER
    }
  }
  