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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   * A very basic @{link TimeInstrument} which can be started and stopped 
29   * once and only once.
30   * 
31   * @author Ceki Gülcü
32   *
33   */
34  public class StopWatch implements TimeInstrument {
35  
36    private String name;
37    private long startTime;
38    private long stopTime;
39    TimeInstrumentStatus status;
40  
41    public StopWatch(String name) {
42      start(name);
43    }
44  
45    StopWatch(StopWatch original) {
46      this.name = original.name;
47      this.startTime = original.startTime;
48      this.stopTime = original.stopTime;
49      this.status = original.status;
50    }
51  
52    
53    public void start(String name) {
54      this.name = name;
55      startTime = System.nanoTime();
56      status = TimeInstrumentStatus.STARTED;
57    }
58    
59    public String getName() {
60      return name;
61    }
62  
63    public TimeInstrument stop() {
64      if(status == TimeInstrumentStatus.STOPPED) {
65        return this;
66      } 
67      return stop(System.nanoTime());
68    }
69  
70    public StopWatch stop(long stopTime) {
71      this.status = TimeInstrumentStatus.STOPPED;
72      this.stopTime = stopTime;
73      return this;
74    }
75    
76    @Override
77    public String toString() {
78      StringBuffer buf = new StringBuffer();
79      buf.append("StopWatch [");
80      buf.append(name);
81      buf.append("] ");
82  
83      switch (status) {
84      case STARTED:
85        buf.append("STARTED");
86        break;
87      case STOPPED:
88        buf.append("elapsed time: ");
89        buf.append(Util.durationInDurationUnitsAsStr(elapsedTime(), DurationUnit.MICROSECOND));
90        break;
91      default:
92        throw new IllegalStateException("Status " + status + " is not expected");
93      }
94      return buf.toString();
95    }
96  
97    public final long elapsedTime() {
98      if (status == TimeInstrumentStatus.STARTED) {
99        return 0;
100     } else {
101       return stopTime - startTime;
102     }
103   }
104 
105   public TimeInstrumentStatus getStatus() {
106     return status;
107   }
108 
109   public void print() {
110    System.out.println(toString());
111   }
112   
113   public void log() {
114     throw new UnsupportedOperationException("A stopwatch instance does not know how to log");
115   }
116   
117 }