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 com.datastax.oss.driver.internal.core.protocol;
  
  import com.datastax.oss.protocol.internal.Compressor;
  import io.netty.buffer.ByteBuf;
  import java.nio.ByteBuffer;
  import net.jcip.annotations.ThreadSafe;
  
  @ThreadSafe
  public abstract class ByteBufCompressor implements Compressor<ByteBuf> {
  
    @Override
    public ByteBuf compress(ByteBuf uncompressed) {
      return uncompressed.isDirect()
          ? compressDirect(uncompressed, true)
          : compressHeap(uncompressed, true);
    }
  
    @Override
    public ByteBuf compressWithoutLength(ByteBuf uncompressed) {
      return uncompressed.isDirect()
          ? compressDirect(uncompressed, false)
          : compressHeap(uncompressed, false);
    }
  
    protected abstract ByteBuf compressDirect(ByteBuf input, boolean prependWithUncompressedLength);
  
    protected abstract ByteBuf compressHeap(ByteBuf input, boolean prependWithUncompressedLength);
  
    @Override
    public ByteBuf decompress(ByteBuf compressed) {
      return decompressWithoutLength(compressed, readUncompressedLength(compressed));
    }
  
    protected abstract int readUncompressedLength(ByteBuf compressed);
  
    @Override
    public ByteBuf decompressWithoutLength(ByteBuf compressed, int uncompressedLength) {
      return compressed.isDirect()
          ? decompressDirect(compressed, uncompressedLength)
          : decompressHeap(compressed, uncompressedLength);
    }
  
    protected abstract ByteBuf decompressDirect(ByteBuf input, int uncompressedLength);
  
    protected abstract ByteBuf decompressHeap(ByteBuf input, int uncompressedLength);
  
    protected static ByteBuffer inputNioBuffer(ByteBuf buf) {
      // Using internalNioBuffer(...) as we only hold the reference in this method and so can
      // reduce Object allocations.
      int index = buf.readerIndex();
      int len = buf.readableBytes();
      return buf.nioBufferCount() == 1
          ? buf.internalNioBuffer(index, len)
          : buf.nioBuffer(index, len);
    }
  
    protected static ByteBuffer outputNioBuffer(ByteBuf buf) {
      int index = buf.writerIndex();
      int len = buf.writableBytes();
      return buf.nioBufferCount() == 1
          ? buf.internalNioBuffer(index, len)
          : buf.nioBuffer(index, len);
    }
  }
  