Class Lz4Codec

java/core/src/java/org/apache/orc/impl/Lz4Codec.java:30–135

import java.nio.ByteBuffer;

public class Lz4Codec implements CompressionCodec, DirectDecompressionCodec {
  private static final LZ4Factory lz4Factory = LZ4Factory.fastestInstance();
  private static final ThreadLocal<byte[]> threadBuffer = ThreadLocal.withInitial(() -> null);

  public Lz4Codec() {}

  protected static byte[] getBuffer(int size) {
    byte[] result = threadBuffer.get();
    if (result == null || result.length < size || result.length > size * 2) {
      result = new byte[size];
      threadBuffer.set(result);
    }
    return result;
  }

  @Override
  public Options getDefaultOptions() {
    return CompressionCodec.NullOptions.INSTANCE;
  }

  @Override
  public boolean compress(ByteBuffer in, ByteBuffer out,
                          ByteBuffer overflow,
                          Options options) throws IOException {
    int inBytes = in.remaining();
    // Skip with minimum size check similar to ZstdCodec
    if (inBytes < 10) return false;

    LZ4Compressor compressor = lz4Factory.fastCompressor();
    int maxOutputLength = compressor.maxCompressedLength(inBytes);
    byte[] compressed = getBuffer(maxOutputLength);

    int outBytes = compressor.compress(in.array(), in.arrayOffset() + in.position(), inBytes,
        compressed, 0, maxOutputLength);

    if (outBytes < inBytes) {
      int remaining = out.remaining();
      if (remaining >= outBytes) {
        System.arraycopy(compressed, 0, out.array(), out.arrayOffset() +
                out.position(), outBytes);
        out.position(out.position() + outBytes);
      } else {
        System.arraycopy(compressed, 0, out.array(), out.arrayOffset() +
                out.position(), remaining);
        out.position(out.limit());
        System.arraycopy(compressed, remaining, overflow.array(),
                overflow.arrayOffset(), outBytes - remaining);
        overflow.position(outBytes - remaining);
      }
      return true;
    } else {
      return false;
    }
  }

  @Override
  public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {
    if (in.isDirect() && out.isDirect()) {