1 /*

     2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package sun.jvmstat.monitor;

    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      */

    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      */

    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      */

   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 

   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 }