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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  package org.apache.hadoop.hbase.hbtop.mode;
19  
20  import org.apache.hadoop.hbase.classification.InterfaceAudience;
21  
22  /**
23   * Utility class for calculating request counts per second.
24   */
25  @InterfaceAudience.Private
26  public class RequestCountPerSecond {
27    private long previousLastReportTimestamp;
28    private long previousReadRequestCount;
29    private long previousWriteRequestCount;
30    private long readRequestCountPerSecond;
31    private long writeRequestCountPerSecond;
32  
33    public void refresh(long lastReportTimestamp, long readRequestCount, long writeRequestCount) {
34      if (previousLastReportTimestamp == 0) {
35        previousLastReportTimestamp = lastReportTimestamp;
36        previousReadRequestCount = readRequestCount;
37        previousWriteRequestCount = writeRequestCount;
38      } else if (previousLastReportTimestamp != lastReportTimestamp) {
39        long delta = (lastReportTimestamp - previousLastReportTimestamp) / 1000;
40        if (delta < 1) {
41          delta = 1;
42        }
43        readRequestCountPerSecond = (readRequestCount - previousReadRequestCount) / delta;
44        writeRequestCountPerSecond = (writeRequestCount - previousWriteRequestCount) / delta;
45  
46        previousLastReportTimestamp = lastReportTimestamp;
47        previousReadRequestCount = readRequestCount;
48        previousWriteRequestCount = writeRequestCount;
49      }
50    }
51  
52    public long getReadRequestCountPerSecond() {
53      return readRequestCountPerSecond < 0 ? 0 : readRequestCountPerSecond;
54    }
55  
56    public long getWriteRequestCountPerSecond() {
57      return writeRequestCountPerSecond < 0 ? 0 : writeRequestCountPerSecond;
58    }
59  
60    public long getRequestCountPerSecond() {
61      return getReadRequestCountPerSecond() + getWriteRequestCountPerSecond();
62    }
63  }