1/*
2 * Copyright (c) 2004, 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
26package sun.jvmstat.perfdata.monitor;
27
28import sun.jvmstat.monitor.*;
29import java.nio.ByteBuffer;
30
31/**
32 * Class for monitoring a constant PerfData String instrument. The
33 * value associated with a constant string instrument is fixed at
34 * the string instrument's creation time. Its value and length never
35 * change.
36 *
37 * @author Brian Doherty
38 * @since 1.5
39 */
40public class PerfStringConstantMonitor extends PerfStringMonitor {
41
42    /**
43     * The cached value of the string instrument.
44     */
45    String data;
46
47    /**
48     * Constructor to create a StringMonitor object for the constant string
49     * instrument object represented by the data in the given buffer.
50     *
51     * @param name the name of the instrumentation object
52     * @param supported support level indicator
53     * @param bb the buffer containing the string instrument data
54     */
55    public PerfStringConstantMonitor(String name, boolean supported,
56                                     ByteBuffer bb) {
57        super(name, Variability.CONSTANT, supported, bb);
58        this.data = super.stringValue();
59    }
60
61    /**
62     * {@inheritDoc}
63     */
64    public Object getValue() {
65        return data;        // return the cached string
66    }
67
68    /**
69     * {@inheritDoc}
70     */
71    public String stringValue() {
72        return data;        // return the cached string
73    }
74}
75