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 com.github.luben.zstd.Zstd;
  import org.apache.arrow.memory.ArrowBuf;
  import org.apache.arrow.memory.BufferAllocator;
  import org.apache.arrow.vector.compression.AbstractCompressionCodec;
  import org.apache.arrow.vector.compression.CompressionUtil;
  
  /** Compression codec for the ZSTD algorithm. */
  public class ZstdCompressionCodec extends AbstractCompressionCodec {
  
    private int compressionLevel;
    private static final int DEFAULT_COMPRESSION_LEVEL = 3;
  
    public ZstdCompressionCodec() {
      this.compressionLevel = DEFAULT_COMPRESSION_LEVEL;
    }
  
    public ZstdCompressionCodec(int compressionLevel) {
      this.compressionLevel = compressionLevel;
    }
  
    @Override
    protected ArrowBuf doCompress(BufferAllocator allocator, ArrowBuf uncompressedBuffer) {
      long maxSize = Zstd.compressBound(uncompressedBuffer.writerIndex());
      long dstSize = CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + maxSize;
      ArrowBuf compressedBuffer = allocator.buffer(dstSize);
      long bytesWritten =
          Zstd.compressUnsafe(
              compressedBuffer.memoryAddress() + CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH,
              dstSize,
              /*src*/ uncompressedBuffer.memoryAddress(),
              /* srcSize= */ uncompressedBuffer.writerIndex(),
              /* level= */ this.compressionLevel);
      if (Zstd.isError(bytesWritten)) {
        compressedBuffer.close();
        throw new RuntimeException("Error compressing: " + Zstd.getErrorName(bytesWritten));
      }
      compressedBuffer.writerIndex(CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH + bytesWritten);
      return compressedBuffer;
    }
  
    @Override
    protected ArrowBuf doDecompress(BufferAllocator allocator, ArrowBuf compressedBuffer) {
      long decompressedLength = readUncompressedLength(compressedBuffer);
      ArrowBuf uncompressedBuffer = allocator.buffer(decompressedLength);
      long decompressedSize =
          Zstd.decompressUnsafe(
              uncompressedBuffer.memoryAddress(),
              decompressedLength,
              /* src= */ compressedBuffer.memoryAddress()
                  + CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH,
              compressedBuffer.writerIndex() - CompressionUtil.SIZE_OF_UNCOMPRESSED_LENGTH);
      if (Zstd.isError(decompressedSize)) {
        uncompressedBuffer.close();
        throw new RuntimeException("Error decompressing: " + Zstd.getErrorName(decompressedSize));
      }
      if (decompressedLength != decompressedSize) {
        uncompressedBuffer.close();
        throw new RuntimeException(
            "Expected != actual decompressed length: "
                + decompressedLength
                + " != "
                + decompressedSize);
      }
      uncompressedBuffer.writerIndex(decompressedLength);
      return uncompressedBuffer;
    }
  
    @Override
    public CompressionUtil.CodecType getCodecType() {
      return CompressionUtil.CodecType.ZSTD;
    }
  }
  