001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.util;
019
020import org.apache.yetus.audience.InterfaceAudience;
021
022/**
023 * Uses an incrementing algorithm instead of the default.
024 */
025@InterfaceAudience.Private
026public class IncrementingEnvironmentEdge implements EnvironmentEdge {
027
028  private long timeIncrement;
029
030  /**
031   * Construct an incremental edge starting from currentTimeMillis
032   */
033  public IncrementingEnvironmentEdge() {
034    this(System.currentTimeMillis());
035  }
036
037  /**
038   * Construct an incremental edge with an initial amount
039   * @param initialAmount the initial value to start with
040   */
041  public IncrementingEnvironmentEdge(long initialAmount) {
042    this.timeIncrement = initialAmount;
043  }
044
045  /**
046   * {@inheritDoc}
047   * <p>
048   * This method increments a known value for the current time each time this method is called. The
049   * first value is 1.
050   * </p>
051   */
052  @Override
053  public synchronized long currentTime() {
054    return timeIncrement++;
055  }
056
057  /**
058   * Increment the time by the given amount
059   */
060  public synchronized long incrementTime(long amount) {
061    timeIncrement += amount;
062    return timeIncrement;
063  }
064}