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) 2002-2025 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 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 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 @Override
60 public void setDescription(final String description)
61 {
62 this.description = description;
63 }
64
65 /**
66 * Process one observed value.
67 * @param value the value to process
68 * @return the value
69 */
70 public long register(final long value)
71 {
72 synchronized (this.semaphore)
73 {
74 this.count += value;
75 this.n++;
76 }
77 return value;
78 }
79
80 /**
81 * Initialize the counter.
82 */
83 @Override
84 public void initialize()
85 {
86 synchronized (this.semaphore)
87 {
88 this.n = 0;
89 this.count = 0;
90 }
91 }
92
93 @Override
94 public String getDescription()
95 {
96 return this.description;
97 }
98
99 /**
100 * Return a string representing a header for a textual table with a monospaced font that can contain multiple statistics.
101 * @return header for the textual table.
102 */
103 public static String reportHeader()
104 {
105 return "-".repeat(72) + String.format("%n| %-48.48s | %6.6s | %8.8s |%n", "Counter name", "n", "count")
106 + "-".repeat(72);
107 }
108
109 @Override
110 public String reportLine()
111 {
112 return String.format("| %-48.48s | %6d | %8d |", getDescription(), getN(), getCount());
113 }
114
115 /**
116 * Return a string representing a footer for a textual table with a monospaced font that can contain multiple statistics.
117 * @return footer for the textual table
118 */
119 public static String reportFooter()
120 {
121 return "-".repeat(72);
122 }
123
124 @Override
125 public String toString()
126 {
127 return "Counter [description=" + this.description + ", n=" + this.n + ", count=" + this.count + "]";
128 }
129
130 }