| /** |
| * 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.distributedlog.util; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| /** |
| * Utils for bit mask operations. |
| */ |
| public class BitMaskUtils { |
| |
| /** |
| * 1) Unset all bits where value in mask is set. |
| * 2) Set these bits to value specified by newValue. |
| * |
| * <p>e.g. |
| * if oldValue = 1010, mask = 0011, newValue = 0001 |
| * 1) 1010 -> 1000 |
| * 2) 1000 -> 1001 |
| * |
| * @param oldValue expected old value |
| * @param mask the mask of the value for updates |
| * @param newValue new value to set |
| * @return updated value |
| */ |
| public static long set(long oldValue, long mask, long newValue) { |
| checkArgument(oldValue >= 0L && mask >= 0L && newValue >= 0L); |
| return ((oldValue & (~mask)) | (newValue & mask)); |
| } |
| |
| /** |
| * Get the bits where mask is 1. |
| * |
| * @param value value |
| * @param mask mask of the value |
| * @return the bit of the mask |
| */ |
| public static long get(long value, long mask) { |
| checkArgument(value >= 0L && mask >= 0L); |
| return (value & mask); |
| } |
| } |