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.cassandra.streaming.compress;
  
  import java.io.IOException;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.ByteBufAllocator;
  import io.netty.buffer.PooledByteBufAllocator;
  import io.netty.buffer.Unpooled;
  import net.jpountz.lz4.LZ4Factory;
  import net.jpountz.lz4.LZ4SafeDecompressor;
  import org.apache.cassandra.io.util.DataInputPlus;
  import org.apache.cassandra.io.util.RebufferingInputStream;
  import org.apache.cassandra.net.AsyncStreamingInputPlus;
  import org.apache.cassandra.streaming.async.StreamCompressionSerializer;
  
  public class StreamCompressionInputStream extends RebufferingInputStream implements AutoCloseable
  {
      /**
       * The stream which contains buffers of compressed data that came from the peer.
       */
      private final DataInputPlus dataInputPlus;
  
      private final LZ4SafeDecompressor decompressor;
      private final int protocolVersion;
      private final StreamCompressionSerializer deserializer;
  
      /**
       * The parent, or owning, buffer of the current buffer being read from ({@link super#buffer}).
       */
      private ByteBuf currentBuf;
  
      public StreamCompressionInputStream(DataInputPlus dataInputPlus, int protocolVersion)
      {
          super(Unpooled.EMPTY_BUFFER.nioBuffer());
          currentBuf = Unpooled.EMPTY_BUFFER;
  
          this.dataInputPlus = dataInputPlus;
          this.protocolVersion = protocolVersion;
          this.decompressor = LZ4Factory.fastestInstance().safeDecompressor();
  
          ByteBufAllocator allocator = dataInputPlus instanceof AsyncStreamingInputPlus
                                       ? ((AsyncStreamingInputPlus)dataInputPlus).getAllocator()
                                       : PooledByteBufAllocator.DEFAULT;
          deserializer = new StreamCompressionSerializer(allocator);
      }
  
      @Override
      public void reBuffer() throws IOException
      {
          currentBuf.release();
          currentBuf = deserializer.deserialize(decompressor, dataInputPlus, protocolVersion);
          buffer = currentBuf.nioBuffer(0, currentBuf.readableBytes());
      }
  
      /**
       * {@inheritDoc}
       *
       * Close resources except {@link #dataInputPlus} as that needs to remain open for other streaming activity.
       */
      @Override
      public void close()
      {
          currentBuf.release();
      }
  }
  