package edu.uci.ics.hivesterix.runtime.factory.comparator;

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.IBinaryComparator;
import edu.uci.ics.hyracks.api.dataflow.value.IBinaryComparatorFactory;

public class HiveIntegerBinaryAscComparatorFactory implements
		IBinaryComparatorFactory {
	private static final long serialVersionUID = 1L;

	public static final HiveIntegerBinaryAscComparatorFactory INSTANCE = new HiveIntegerBinaryAscComparatorFactory();

	private HiveIntegerBinaryAscComparatorFactory() {
	}

	@Override
	public IBinaryComparator createBinaryComparator() {
		return new IBinaryComparator() {
			private VInt left = new VInt();
			private VInt right = new VInt();

			@Override
			public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2,
					int l2) {
				LazyUtils.readVInt(b1, s1, left);
				LazyUtils.readVInt(b2, s2, right);

				if (left.length != l1 || right.length != l2)
					throw new IllegalArgumentException(
							"length mismatch in int comparator function actual: "
									+ left.length + "," + right.length
									+ " expected " + l1 + "," + l2);

				if (left.value > right.value)
					return 1;
				else if (left.value == right.value)
					return 0;
				else
					return -1;
			}
		};
	}
}