package org.apache.lucene.mockfile;

/*
 * 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.
 */

import java.io.IOError;
import java.io.IOException;
import java.lang.reflect.Method;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Objects;

/**  
 * A {@code FilterFileChannel} contains another 
 * {@code FileChannel}, which it uses as its basic 
 * source of data, possibly transforming the data along the 
 * way or providing additional functionality. 
 */
public class FilterFileChannel extends FileChannel {
  
  /** 
   * The underlying {@code FileChannel} instance. 
   */
  protected final FileChannel delegate;
  
  /**
   * Construct a {@code FilterFileChannel} based on 
   * the specified base channel.
   * <p>
   * Note that base channel is closed if this channel is closed.
   * @param delegate specified base channel.
   */
  public FilterFileChannel(FileChannel delegate) {
    this.delegate = Objects.requireNonNull(delegate);
  }

  @Override
  public int read(ByteBuffer dst) throws IOException {
    return delegate.read(dst);
  }

  @Override
  public long read(ByteBuffer[] dsts, int offset, int length) throws IOException {
    return delegate.read(dsts, offset, length);
  }

  @Override
  public int write(ByteBuffer src) throws IOException {
    return delegate.write(src);
  }

  @Override
  public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
    return delegate.write(srcs, offset, length);
  }

  @Override
  public long position() throws IOException {
    return delegate.position();
  }

  @Override
  public FileChannel position(long newPosition) throws IOException {
    delegate.position(newPosition);
    return this;
  }

  @Override
  public long size() throws IOException {
    return delegate.size();
  }

  @Override
  public FileChannel truncate(long size) throws IOException {
    delegate.truncate(size);
    return this;
  }

  @Override
  public void force(boolean metaData) throws IOException {
    delegate.force(metaData);
  }

  @Override
  public long transferTo(long position, long count, WritableByteChannel target) throws IOException {
    return delegate.transferTo(position, count, target);
  }

  @Override
  public long transferFrom(ReadableByteChannel src, long position, long count) throws IOException {
    return delegate.transferFrom(src, position, count);
  }

  @Override
  public int read(ByteBuffer dst, long position) throws IOException {
    return delegate.read(dst, position);
  }

  @Override
  public int write(ByteBuffer src, long position) throws IOException {
    return delegate.write(src, position);
  }

  @Override
  public MappedByteBuffer map(MapMode mode, long position, long size) throws IOException {
    return delegate.map(mode, position, size);
  }

  @Override
  public FileLock lock(long position, long size, boolean shared) throws IOException {
    return delegate.lock(position, size, shared);
  }

  @Override
  public FileLock tryLock(long position, long size, boolean shared) throws IOException {
    return delegate.tryLock(position, size, shared);
  }

  @Override
  protected void implCloseChannel() throws IOException {
    // our only way to call delegate.implCloseChannel()
    AccessController.doPrivileged(new PrivilegedAction<Void>() {
      @Override
      public Void run() {
        for (Class<?> clazz = delegate.getClass(); clazz != null; clazz = clazz.getSuperclass()) {
          final Method method;
          try {
            method = clazz.getDeclaredMethod("implCloseChannel");
          } catch (NoSuchMethodException e) {
            continue;
          }
          try {
            method.setAccessible(true);
            method.invoke(delegate);
            return null;
          } catch (ReflectiveOperationException e) {
            throw new IOError(e);
          }
        }
        throw new AssertionError();
      }
    });
  }
}

@@ -855,73 +855,16 @@
 .IOE
-rror;%0Aimport java.io.IOException;%0Aimport java.lang.reflect.Method
+xception
 ;%0Aim
@@ -1092,86 +1092,8 @@
 el;%0A
-import java.security.AccessController;%0Aimport java.security.PrivilegedAction;%0A
 impo
@@ -4035,732 +4035,174 @@
  // 
-our only way to call delegate.implCloseChannel()%0A    AccessController.doPrivileged(new PrivilegedAction%3CVoid%3E() %7B%0A      @Override%0A      public Void run() %7B%0A        for (Class%3C?%3E clazz = delegate.getClass(); clazz != null; clazz = clazz.getSuperclass()) %7B%0A          final Method method;%0A          try %7B%0A            method = clazz.getDeclaredMethod(%22implCloseChannel%22);%0A          %7D catch (NoSuchMethodException e) %7B%0A            continue;%0A          %7D%0A          try %7B%0A            method.setAccessible(true);%0A            method.invoke(delegate);%0A            return null;%0A          %7D catch (ReflectiveOperationException e) %7B%0A            throw new IOError(e);%0A          %7D%0A        %7D%0A        throw new AssertionError();%0A      %7D%0A    %7D
+we can't call implCloseChannel, but calling this instead is %22ok%22:%0A    // http://mail.openjdk.java.net/pipermail/nio-dev/2015-September/003322.html%0A    delegate.close(
 );%0A 

remove reflection hack completely, see http://mail.openjdk.java.net/pipermail/nio-dev/2015-September/003322.html