hivesterix/hivesterix-runtime/src/main/java/edu/uci/ics/hivesterix/runtime/factory/hashfunction/HiveIntegerBinaryHashFunctionFactory.java

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

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.IBinaryHashFunction;
import edu.uci.ics.hyracks.api.dataflow.value.IBinaryHashFunctionFactory;

public class HiveIntegerBinaryHashFunctionFactory implements IBinaryHashFunctionFactory {
    private static final long serialVersionUID = 1L;

    public static IBinaryHashFunctionFactory INSTANCE = new HiveIntegerBinaryHashFunctionFactory();

    private HiveIntegerBinaryHashFunctionFactory() {
    }

    @Override
    public IBinaryHashFunction createBinaryHashFunction() {

        return new IBinaryHashFunction() {
            private VInt value = new VInt();

            @Override
            public int hash(byte[] bytes, int offset, int length) {
                LazyUtils.readVInt(bytes, offset, value);
                if (value.length != length)
                    throw new IllegalArgumentException("length mismatch in int hash function actual: " + length
                            + " expected " + value.length);
                return value.value;
            }
        };
    }

}