1 /*
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19 package org.apache.hadoop.hbase.util;
20
21 import org.apache.hadoop.hbase.classification.InterfaceAudience;
22
23 /**
24 * Uses an incrementing algorithm instead of the default.
25 */
26 @InterfaceAudience.Private
27 public class IncrementingEnvironmentEdge implements EnvironmentEdge {
28
29 private long timeIncrement;
30
31 /**
32 * Construct an incremental edge starting from currentTimeMillis
33 */
34 public IncrementingEnvironmentEdge() {
35 this(System.currentTimeMillis());
36 }
37
38 /**
39 * Construct an incremental edge with an initial amount
40 * @param initialAmount the initial value to start with
41 */
42 public IncrementingEnvironmentEdge(long initialAmount) {
43 this.timeIncrement = initialAmount;
44 }
45
46 /**
47 * {@inheritDoc}
48 * <p/>
49 * This method increments a known value for the current time each time this
50 * method is called. The first value is 1.
51 */
52 @Override
53 public synchronized long currentTime() {
54 return timeIncrement++;
55 }
56
57 /**
58 * Increment the time by the given amount
59 */
60 public synchronized long incrementTime(long amount) {
61 timeIncrement += amount;
62 return timeIncrement;
63 }
64 }