1 package org.djutils.stats.summarizers;
2
3 import org.djutils.exceptions.Throw;
4
5 /**
6 * The Counter class defines a statistics event counter.
7 * <p>
8 * Copyright (c) 2002-2024 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
9 * for project information <a href="https://simulation.tudelft.nl/" target="_blank"> https://simulation.tudelft.nl</a>. The DSOL
10 * project is distributed under a three-clause BSD-style license, which can be found at
11 * <a href="https://simulation.tudelft.nl/dsol/3.0/license.html" target="_blank">
12 * https://simulation.tudelft.nl/dsol/3.0/license.html</a>. <br>
13 * @author <a href="https://www.tudelft.nl/averbraeck" target="_blank"> Alexander Verbraeck</a>
14 * @author <a href="https://www.linkedin.com/in/peterhmjacobs">Peter Jacobs </a>
15 */
16 public class Counter implements Statistic
17 {
18 /** */
19 private static final long serialVersionUID = 20200228L;
20
21 /** count represents the value of the counter. */
22 private long count = 0;
23
24 /** n represents the number of measurements. */
25 private long n = 0;
26
27 /** description refers to the title of this counter. */
28 private String description;
29
30 /** the semaphore. */
31 private Object semaphore = new Object();
32
33 /**
34 * Constructs a new Counter.
35 * @param description String; the description for this counter
36 */
37 public Counter(final String description)
38 {
39 Throw.whenNull(description, "description cannot be null");
40 this.description = description;
41 initialize();
42 }
43
44 /**
45 * Returns the current counter value.
46 * @return long; the counter value
47 */
48 public long getCount()
49 {
50 return this.count;
51 }
52
53 @Override
54 public long getN()
55 {
56 return this.n;
57 }
58
59 /**
60 * Process one observed value.
61 * @param value long; the value to process
62 * @return long; the value
63 */
64 public long register(final long value)
65 {
66 synchronized (this.semaphore)
67 {
68 this.count += value;
69 this.n++;
70 }
71 return value;
72 }
73
74 /**
75 * Initialize the counter.
76 */
77 @Override
78 public void initialize()
79 {
80 synchronized (this.semaphore)
81 {
82 this.n = 0;
83 this.count = 0;
84 }
85 }
86
87 @Override
88 public String getDescription()
89 {
90 return this.description;
91 }
92
93 /**
94 * Return a string representing a header for a textual table with a monospaced font that can contain multiple statistics.
95 * @return String; header for the textual table.
96 */
97 public static String reportHeader()
98 {
99 return "-".repeat(72) + String.format("%n| %-48.48s | %6.6s | %8.8s |%n", "Counter name", "n", "count")
100 + "-".repeat(72);
101 }
102
103 @Override
104 public String reportLine()
105 {
106 return String.format("| %-48.48s | %6d | %8d |", getDescription(), getN(), getCount());
107 }
108
109 /**
110 * Return a string representing a footer for a textual table with a monospaced font that can contain multiple statistics.
111 * @return String; footer for the textual table
112 */
113 public static String reportFooter()
114 {
115 return "-".repeat(72);
116 }
117
118 @Override
119 public String toString()
120 {
121 return "Counter [description=" + this.description + ", n=" + this.n + ", count=" + this.count + "]";
122 }
123
124 }