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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  /**
30   * 
31   * This demo illustrates usage of SLF4J profilers.
32   * 
33   * <p>
34   * We have been given the task of generating a large number, say N, 
35   * of random integers. We need to transform that array into a smaller array
36   * containing only prime numbers. The new array has to be sorted.
37   * 
38   * <p>
39   * While tackling this problem, we would like to measure the
40   * time spent in each subtask.
41   * 
42   * <p>
43   * A typical output for this demo would be:
44   <pre>
45   + Profiler [DEMO]
46  |-- elapsed time                       [RANDOM]     0.089  seconds.
47  |---+ Profiler [SORT_AND_PRUNE]
48  &nbsp;&nbsp;&nbsp;&nbsp;|-- elapsed time                         [SORT]     0.221  seconds.
49  &nbsp;&nbsp;&nbsp;&nbsp;|-- elapsed time             [PRUNE_COMPOSITES]    11.567  seconds.
50  &nbsp;&nbsp;&nbsp;&nbsp;|-- Subtotal                   [SORT_AND_PRUNE]    11.788  seconds.
51  |-- elapsed time               [SORT_AND_PRUNE]    11.788  seconds.
52  |-- Total                                [DEMO]    11.877  seconds.
53  </pre>
54   * 
55   * @author Ceki Gulcu
56   */
57  public class NestedProfilerDemo {
58    
59    public static void main(String[] args) {
60      // create a profiler called "DEMO"
61      Profiler profiler = new Profiler("DEMO");
62      
63      // register this profiler in the thread context's profiler registry
64      ProfilerRegistry profilerRegistry = ProfilerRegistry.getThreadContextInstance();
65      profiler.registerWith(profilerRegistry);
66      
67      // start a stopwatch called "RANDOM"
68      profiler.start("RANDOM");
69      RandomIntegerArrayGenerator riaGenerator = new RandomIntegerArrayGenerator();
70      int n = 10*1000;
71      int[] randomArray = riaGenerator.generate(n);
72      
73      // create and start a nested profiler called "SORT_AND_PRUNE"
74      // By virtue of its parent-child relationship with the "DEMO"
75      // profiler, and the previous registration of the parent profiler, 
76      // this nested profiler will be automatically registered
77      // with the thread context's profiler registry
78      profiler.startNested(SortAndPruneComposites.NESTED_PROFILER_NAME);
79      
80      SortAndPruneComposites pruner = new SortAndPruneComposites(randomArray);
81      pruner.sortAndPruneComposites();
82      
83      // stop and print the "DEMO" printer
84      profiler.stop().print();
85    }
86  }