io.virtdata.long_int.SignedHash Maven / Gradle / Ivy
package io.virtdata.long_int;
import de.greenrobot.common.hash.Murmur3F;
import java.nio.ByteBuffer;
import java.util.function.LongToIntFunction;
/**
* This uses the Murmur3F (64-bit optimized) version of Murmur3,
* not as a checksum, but as a simple hash. It doesn't bother
* pushing the high-64 bits of input, since it only uses the lower
* 64 bits of output. This version returns the full signed result.
*/
public class SignedHash implements LongToIntFunction {
private ByteBuffer bb = ByteBuffer.allocate(Long.BYTES);
private Murmur3F murmur3F= new Murmur3F();
@Override
public int applyAsInt(long value) {
murmur3F.reset();
bb.putLong(0,value);
murmur3F.update(bb.array(),0,Long.BYTES);
long result= murmur3F.getValue();
return (int) (result & Integer.MAX_VALUE);
}
}