/*
 * 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.lucene.store;


import java.io.IOException;
import java.util.Collection;
import java.util.Set;

Directory implementation that delegates calls to another directory. This class can be used to add limitations on top of an existing Directory implementation such as NRTCachingDirectory or to add additional sanity checks for tests. However, if you plan to write your own Directory implementation, you should consider extending directly Directory or BaseDirectory rather than try to reuse functionality of existing Directorys by extending this class. @lucene.internal /** Directory implementation that delegates calls to another directory.
 *  This class can be used to add limitations on top of an existing
 *  {@link Directory} implementation such as
 *  {@link NRTCachingDirectory} or to add additional
 *  sanity checks for tests. However, if you plan to write your own
 *  {@link Directory} implementation, you should consider extending directly
 *  {@link Directory} or {@link BaseDirectory} rather than try to reuse
 *  functionality of existing {@link Directory}s by extending this class.
 *  @lucene.internal */
public abstract class FilterDirectory extends Directory {

  
Get the wrapped instance by dir as long as this reader is an instance of FilterDirectory. /** Get the wrapped instance by <code>dir</code> as long as this reader is
   *  an instance of {@link FilterDirectory}.  */
  public static Directory unwrap(Directory dir) {
    while (dir instanceof FilterDirectory) {
      dir = ((FilterDirectory) dir).in;
    }
    return dir;
  }

  protected final Directory in;

  
Sole constructor, typically called from sub-classes. /** Sole constructor, typically called from sub-classes. */
  protected FilterDirectory(Directory in) {
    this.in = in;
  }

  
Return the wrapped Directory. /** Return the wrapped {@link Directory}. */
  public final Directory getDelegate() {
    return in;
  }

  @Override
  public String[] listAll() throws IOException {
    return in.listAll();
  }

  @Override
  public void deleteFile(String name) throws IOException {
    in.deleteFile(name);
  }

  @Override
  public long fileLength(String name) throws IOException {
    return in.fileLength(name);
  }

  @Override
  public IndexOutput createOutput(String name, IOContext context)
      throws IOException {
    return in.createOutput(name, context);
  }

  @Override
  public IndexOutput createTempOutput(String prefix, String suffix, IOContext context) throws IOException {
    return in.createTempOutput(prefix, suffix, context);
  }

  @Override
  public void sync(Collection<String> names) throws IOException {
    in.sync(names);
  }

  @Override
  public void rename(String source, String dest) throws IOException {
    in.rename(source, dest);
  }

  @Override
  public void syncMetaData() throws IOException {
    in.syncMetaData();
  }

  @Override
  public IndexInput openInput(String name, IOContext context)
      throws IOException {
    return in.openInput(name, context);
  }

  @Override
  public Lock obtainLock(String name) throws IOException {
    return in.obtainLock(name);
  }

  @Override
  public void close() throws IOException {
    in.close();
  }

  @Override
  public String toString() {
    return getClass().getSimpleName() + "(" + in.toString() + ")";
  }

  @Override
  public Set<String> getPendingDeletions() throws IOException {
    return in.getPendingDeletions();
  }
}