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.celeborn.common.network.buffer;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteBuffer;
  
  /**
   * This interface provides an immutable view for data in the form of bytes. The implementation
   * should specify how the data is provided:
   *
   * <p>- {@link FileSegmentManagedBuffer}: data backed by part of a file - {@link NioManagedBuffer}:
   * data backed by a NIO ByteBuffer - {@link NettyManagedBuffer}: data backed by a Netty ByteBuf
   *
   * <p>The concrete buffer implementation might be managed outside the JVM garbage collector. For
   * example, in the case of {@link NettyManagedBuffer}, the buffers are reference counted. In that
   * case, if the buffer is going to be passed around to a different thread, retain/release should be
   * called.
   */
  public abstract class ManagedBuffer {
  
    /**
     * Number of bytes of the data. If this buffer will decrypt for all of the views into the data,
     * this is the size of the decrypted data.
     */
    public abstract long size();
  
    /**
     * Exposes this buffer's data as an NIO ByteBuffer. Changing the position and limit of the
     * returned ByteBuffer should not affect the content of this buffer.
     */
    public abstract ByteBuffer nioByteBuffer() throws IOException;
  
    /**
     * Exposes this buffer's data as an InputStream. The underlying implementation does not
     * necessarily check for the length of bytes read, so the caller is responsible for making sure it
     * does not go over the limit.
     */
    public abstract InputStream createInputStream() throws IOException;
  
    /** Increment the reference count by one if applicable. */
    public abstract ManagedBuffer retain();
  
    /**
     * If applicable, decrement the reference count by one and deallocates the buffer if the reference
     * count reaches zero.
     */
    public abstract ManagedBuffer release();
  
    /**
     * Convert the buffer into a Netty object, used to write the data out. The return value is either
     * a {@link io.netty.buffer.ByteBuf} or a {@link io.netty.channel.FileRegion}.
     *
     * <p>If this method returns a ByteBuf, then that buffer's reference count will be incremented and
     * the caller will be responsible for releasing this new reference.
     */
    public abstract Object convertToNetty() throws IOException;
  
    /**
     * Convert the buffer into a Netty object, used to write the data out with SSL encryption, which
     * cannot use {@link io.netty.channel.FileRegion}. The return value is either a {@link
     * io.netty.buffer.ByteBuf}, a {@link io.netty.handler.stream.ChunkedStream}, or a {@link
     * java.io.InputStream}.
     *
     * <p>If this method returns a ByteBuf, then that buffer's reference count will be incremented and
     * the caller will be responsible for releasing this new reference.
     */
    public abstract Object convertToNettyForSsl() throws IOException;
  }
  