spork-master/src/org/apache/pig/data/utils/BytesHelper.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.pig.data.utils;

public class BytesHelper {
    private static final int[] mask = {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80};
    private static final int[] invMask = {0xFE, 0xFD, 0xFB, 0xF7, 0xEF, 0xDF, 0xBF, 0x7F};

    public static boolean getBitByPos(byte byt, int pos) {
        return (byt & mask[pos]) > 0;
    }

    public static byte setBitByPos(byte byt, boolean bool, int pos) {
        if (bool) {
            return (byte)((int)byt | mask[pos]);
        } else {
            return (byte)((int)byt & invMask[pos]);
        }
    }
}
