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.arrow.compression;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.util.Preconditions;
  import org.apache.arrow.vector.compression.AbstractCompressionCodec;
  import org.apache.arrow.vector.compression.CompressionUtil;
  import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorInputStream;
  import org.apache.commons.compress.compressors.lz4.FramedLZ4CompressorOutputStream;
  import org.apache.commons.compress.utils.IOUtils;
  
  /** Compression codec for the LZ4 algorithm. */
  public class Lz4CompressionCodec extends AbstractCompressionCodec {
  
    @Override
    protected ArrowBuf doCompress(BufferAllocator allocator, ArrowBuf uncompressedBuffer) {
      Preconditions.checkArgument(
          uncompressedBuffer.writerIndex() <= Integer.MAX_VALUE,
          "The uncompressed buffer size exceeds the integer limit %s.",
          Integer.MAX_VALUE);
  
      byte[] inBytes = new byte[(int) uncompressedBuffer.writerIndex()];
      uncompressedBuffer.getBytes(/* index= */ 0, inBytes);
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      try (InputStream in = new ByteArrayInputStream(inBytes);
          OutputStream out = new FramedLZ4CompressorOutputStream(baos)) {
        IOUtils.copy(in, out);
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
  
      byte[] outBytes = baos.toByteArray();
  
      ArrowBuf compressedBuffer =
          allocator.buffer(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + outBytes.length);
      compressedBuffer.setBytes(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH, outBytes);
      compressedBuffer.writerIndex(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + outBytes.length);
      return compressedBuffer;
    }
  
    @Override
    protected ArrowBuf doDecompress(BufferAllocator allocator, ArrowBuf compressedBuffer) {
      Preconditions.checkArgument(
          compressedBuffer.writerIndex() <= Integer.MAX_VALUE,
          "The compressed buffer size exceeds the integer limit %s",
          Integer.MAX_VALUE);
  
      long decompressedLength = readUncompressedLength(compressedBuffer);
  
      byte[] inBytes =
          new byte
              [(int) (compressedBuffer.writerIndex() - CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH)];
      compressedBuffer.getBytes(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH, inBytes);
      ByteArrayOutputStream out = new ByteArrayOutputStream((int) decompressedLength);
      try (InputStream in = new FramedLZ4CompressorInputStream(new ByteArrayInputStream(inBytes))) {
        IOUtils.copy(in, out);
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
  
      byte[] outBytes = out.toByteArray();
      ArrowBuf decompressedBuffer = allocator.buffer(outBytes.length);
      decompressedBuffer.setBytes(/* index= */ 0, outBytes);
      decompressedBuffer.writerIndex(decompressedLength);
      return decompressedBuffer;
    }
  
    @Override
    public CompressionUtil.CodecType getCodecType() {
      return CompressionUtil.CodecType.LZ4_FRAME;
    }
  }
  