| /** |
| * 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.hadoop.hdfs.util; |
| |
| import java.io.Serializable; |
| |
| |
| /** |
| * Bit format in a long. |
| */ |
| public class LongBitFormat implements Serializable { |
| private static final long serialVersionUID = 1L; |
| |
| public interface Enum { |
| int getLength(); |
| } |
| |
| private final String NAME; |
| /** Bit offset */ |
| private final int OFFSET; |
| /** Bit length */ |
| private final int LENGTH; |
| /** Minimum value */ |
| private final long MIN; |
| /** Maximum value */ |
| private final long MAX; |
| /** Bit mask */ |
| private final long MASK; |
| |
| public LongBitFormat(String name, LongBitFormat previous, int length, |
| long min) { |
| NAME = name; |
| OFFSET = previous == null? 0: previous.OFFSET + previous.LENGTH; |
| LENGTH = length; |
| MIN = min; |
| MAX = ((-1L) >>> (64 - LENGTH)); |
| MASK = MAX << OFFSET; |
| } |
| |
| /** Retrieve the value from the record. */ |
| public long retrieve(long record) { |
| return (record & MASK) >>> OFFSET; |
| } |
| |
| /** Combine the value to the record. */ |
| public long combine(long value, long record) { |
| if (value < MIN) { |
| throw new IllegalArgumentException( |
| "Illagal value: " + NAME + " = " + value + " < MIN = " + MIN); |
| } |
| if (value > MAX) { |
| throw new IllegalArgumentException( |
| "Illagal value: " + NAME + " = " + value + " > MAX = " + MAX); |
| } |
| return (record & ~MASK) | (value << OFFSET); |
| } |
| |
| public long getMin() { |
| return MIN; |
| } |
| |
| public int getLength() { |
| return LENGTH; |
| } |
| } |