package FlexibleEncoding.ORC;
/**
adapted from ORC
@author wangmeng
*/
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;
public class ZlibCodec implements CompressionCodec {
@Override
public boolean compress(ByteBuffer in, ByteBuffer out,
ByteBuffer overflow) throws IOException {
Deflater deflater = new Deflater(Deflater.DEFAULT_COMPRESSION, true);
int length = in.remaining();
deflater.setInput(in.array(), in.arrayOffset() + in.position(), length);
deflater.finish();
int outSize = 0;
int offset = out.arrayOffset() + out.position();
while (!deflater.finished() && (length > outSize)) {
int size = deflater.deflate(out.array(), offset, out.remaining());
out.position(size + out.position());
outSize += size;
offset += size;
// if we run out of space in the out buffer, use the overflow
if (out.remaining() == 0) {
if (overflow == null) {
deflater.end();
return false;
}
out = overflow;
offset = out.arrayOffset() + out.position();
}
}
deflater.end();
return length > outSize;
}
@Override
public void decompress(ByteBuffer in, ByteBuffer out) throws IOException {
Inflater inflater = new Inflater(true);
inflater.setInput(in.array(), in.arrayOffset() + in.position(),
in.remaining());
while (!(inflater.finished() || inflater.needsDictionary() ||
inflater.needsInput())) {
try {
int count = inflater.inflate(out.array(),
out.arrayOffset() + out.position(),
out.remaining());
out.position(count + out.position());
} catch (DataFormatException dfe) {
throw new IOException("Bad compression data", dfe);
}
}
out.flip();
inflater.end();
in.position(in.limit());
}
}