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1   /**
2    * Copyright (c) 2004-2011 QOS.ch
3    * All rights reserved.
4    *
5    * Permission is hereby granted, free  of charge, to any person obtaining
6    * a  copy  of this  software  and  associated  documentation files  (the
7    * "Software"), to  deal in  the Software without  restriction, including
8    * without limitation  the rights to  use, copy, modify,  merge, publish,
9    * distribute,  sublicense, and/or sell  copies of  the Software,  and to
10   * permit persons to whom the Software  is furnished to do so, subject to
11   * the following conditions:
12   *
13   * The  above  copyright  notice  and  this permission  notice  shall  be
14   * included in all copies or substantial portions of the Software.
15   *
16   * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
17   * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
18   * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
19   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21   * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
22   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23   *
24   */
25  package org.slf4j.profiler;
26  
27  /**
28   * 
29   * This demo illustrates usage of SLF4J profilers.
30   * 
31   * <p>
32   * We have been given the task of generating a large number, say N, 
33   * of random integers. We need to transform that array into a smaller array
34   * containing only prime numbers. The new array has to be sorted.
35   * 
36   * <p>
37   * While tackling this problem, we would like to measure the
38   * time spent in each subtask.
39   * 
40   * <p>
41   * A typical output for this demo would be:
42   <pre>
43   + Profiler [DEMO]
44  |-- elapsed time                       [RANDOM]     0.089  seconds.
45  |---+ Profiler [SORT_AND_PRUNE]
46  &nbsp;&nbsp;&nbsp;&nbsp;|-- elapsed time                         [SORT]     0.221  seconds.
47  &nbsp;&nbsp;&nbsp;&nbsp;|-- elapsed time             [PRUNE_COMPOSITES]    11.567  seconds.
48  &nbsp;&nbsp;&nbsp;&nbsp;|-- Subtotal                   [SORT_AND_PRUNE]    11.788  seconds.
49  |-- elapsed time               [SORT_AND_PRUNE]    11.788  seconds.
50  |-- Total                                [DEMO]    11.877  seconds.
51  </pre>
52   * 
53   * @author Ceki Gulcu
54   */
55  public class NestedProfilerDemo {
56  
57      public static void main(String[] args) {
58          // create a profiler called "DEMO"
59          Profiler profiler = new Profiler("DEMO");
60  
61          // register this profiler in the thread context's profiler registry
62          ProfilerRegistry profilerRegistry = ProfilerRegistry.getThreadContextInstance();
63          profiler.registerWith(profilerRegistry);
64  
65          // start a stopwatch called "RANDOM"
66          profiler.start("RANDOM");
67          RandomIntegerArrayGenerator riaGenerator = new RandomIntegerArrayGenerator();
68          int n = 10 * 1000;
69          int[] randomArray = riaGenerator.generate(n);
70  
71          // create and start a nested profiler called "SORT_AND_PRUNE"
72          // By virtue of its parent-child relationship with the "DEMO"
73          // profiler, and the previous registration of the parent profiler,
74          // this nested profiler will be automatically registered
75          // with the thread context's profiler registry
76          profiler.startNested(SortAndPruneComposites.NESTED_PROFILER_NAME);
77  
78          SortAndPruneComposites pruner = new SortAndPruneComposites(randomArray);
79          pruner.sortAndPruneComposites();
80  
81          // stop and print the "DEMO" printer
82          profiler.stop().print();
83      }
84  }