package edu.uci.ics.hivesterix.runtime.factory.normalize;

import edu.uci.ics.hivesterix.serde.lazy.LazyUtils;
import edu.uci.ics.hivesterix.serde.lazy.LazyUtils.VInt;
import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputer;
import edu.uci.ics.hyracks.api.dataflow.value.INormalizedKeyComputerFactory;

public class HiveIntegerDescNormalizedKeyComputerFactory implements
		INormalizedKeyComputerFactory {

	private static final long serialVersionUID = 1L;

	@Override
	public INormalizedKeyComputer createNormalizedKeyComputer() {

		return new INormalizedKeyComputer() {
			private VInt vint = new VInt();

			@Override
			public int normalize(byte[] bytes, int start, int length) {
				LazyUtils.readVInt(bytes, start, vint);
				if (vint.length != length)
					throw new IllegalArgumentException(
							"length mismatch in int comparator function actual: "
									+ vint.length + " expected " + length);
				long unsignedValue = (long) vint.value;
				return (int) ((long) 0xffffffff - unsignedValue);
			}
		};
	}
}