package org.apache.avro.file;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.zip.CRC32;
import org.xerial.snappy.Snappy;
public class SnappyCodec extends Codec {
private CRC32 crc32 = new CRC32();
static class Option extends CodecFactory {
static {
Snappy.getNativeLibraryVersion();
}
@Override
protected Codec createInstance() {
return new SnappyCodec();
}
}
private SnappyCodec() {
}
@Override
public String getName() {
return DataFileConstants.SNAPPY_CODEC;
}
@Override
public ByteBuffer compress(ByteBuffer in) throws IOException {
int offset = computeOffset(in);
ByteBuffer out = ByteBuffer.allocate(Snappy.maxCompressedLength(in.remaining()) + 4);
int size = Snappy.compress(in.array(), offset, in.remaining(), out.array(), 0);
crc32.reset();
crc32.update(in.array(), offset, in.remaining());
out.putInt(size, (int) crc32.getValue());
out.limit(size + 4);
return out;
}
@Override
public ByteBuffer decompress(ByteBuffer in) throws IOException {
int offset = computeOffset(in);
ByteBuffer out = ByteBuffer.allocate(Snappy.uncompressedLength(in.array(), offset, in.remaining() - 4));
int size = Snappy.uncompress(in.array(), offset, in.remaining() - 4, out.array(), 0);
out.limit(size);
crc32.reset();
crc32.update(out.array(), 0, size);
if (in.getInt(in.limit() - 4) != (int) crc32.getValue())
throw new IOException("Checksum failure");
return out;
}
@Override
public int hashCode() {
return getName().hashCode();
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
return obj != null && obj.getClass() == getClass();
}
}