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25 
26 package sun.management.counter;
27 
28 /**
29  * Provides a typesafe enumeration for describing units of measurement
30  * attribute for instrumentation objects.
31  *
32  * @author   Brian Doherty
33  */
34 public class Units implements java.io.Serializable {
35 
36     /* The enumeration values for this typesafe enumeration must be
37      * kept in synchronization with the Units enum in the perfData.hpp file
38      * in the HotSpot source base.
39      */
40 
41     private static final int NUNITS=8;
42 
43     private static Units[] map = new Units[NUNITS];
44 
45     private final String name;
46     private final int value;
47 
48     /**
49      * An Invalid Units value.
50      */
51     public static final Units INVALID = new Units("Invalid", 0);
52 
53     /**
54      * Units attribute representing unit-less quantities.
55      */
56     public static final Units NONE = new Units("None", 1);
57 
58     /**
59      * Units attribute representing Bytes.
60      */
61     public static final Units BYTES = new Units("Bytes", 2);
62 
63     /**
64      * Units attribute representing Ticks.
65      */
66     public static final Units TICKS = new Units("Ticks", 3);
67 
68     /**
69      * Units attribute representing a count of events.
70      */
71     public static final Units EVENTS = new Units("Events", 4);
72 
73     /**
74      * Units attribute representing String data. Although not really
75      * a unit of measure, this Units value serves to distinguish String
76      * instrumentation objects from instrumentation objects of other types.
77      */
78     public static final Units STRING = new Units("String", 5);
79 
80     /**
81      * Units attribute representing Hertz (frequency).
82      */
83     public static final Units HERTZ = new Units("Hertz", 6);
84 
85     /**
86      * Returns a string describing this Unit of measurement attribute
87      *
88      * @return String - a descriptive string for this enum.
89      */
toString()90     public String toString() {
91         return name;
92     }
93 
94     /**
95      * Returns the integer representation of this Units attribute
96      *
97      * @return int - an integer representation of this Units attribute.
98      */
intValue()99     public int intValue() {
100         return value;
101     }
102 
103     /**
104      * Maps an integer value to its corresponding Units attribute.
105      * If the integer value does not have a corresponding Units enum
106      * value, then {@link Units#INVALID} is returned.
107      *
108      * @param value an integer representation of counter Units
109      * @return Units - the Units object for the given <code>value</code>
110      *                 or {@link Units#INVALID} if out of range.
111      */
toUnits(int value)112     public static Units toUnits(int value) {
113 
114         if (value < 0 || value >= map.length || map[value] == null) {
115             return INVALID;
116         }
117 
118         return map[value];
119     }
120 
Units(String name, int value)121     private Units(String name, int value) {
122         this.name = name;
123         this.value = value;
124         map[value] = this;
125     }
126 
127     private static final long serialVersionUID = 6992337162326171013L;
128 }
129