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 PerfData Byte Array instrumentation object. 33 * 34 * This class is provided to support the PerfStringMonitor classes. 35 * Instrumentation objects of this direct type currently cannot be 36 * created or monitored. 37 * 38 * @author Brian Doherty 39 * @since 1.5 40 * @see sun.jvmstat.instrument.ByteArrayInstrument 41 */ 42public class PerfByteArrayMonitor extends AbstractMonitor 43 implements ByteArrayMonitor { 44 45 /** 46 * The buffer containing the data for the byte array instrument. 47 */ 48 ByteBuffer bb; 49 50 /** 51 * Constructor to create a ByteArrayMonitor for the byte array instrument 52 * represented by the data in the given buffer. 53 * 54 * @param name the name of the instrumentation object 55 * @param u the units of measure attribute 56 * @param v the variability attribute 57 * @param supported support level indicator 58 * @param bb the buffer containing the byte array instrument data 59 * @param vectorLength the length of the vector. 60 */ 61 public PerfByteArrayMonitor(String name, Units u, Variability v, 62 boolean supported, ByteBuffer bb, 63 int vectorLength) { 64 super(name, u, v, supported, vectorLength); 65 this.bb = bb; 66 } 67 68 /** 69 * {@inheritDoc} 70 * The object returned contains a byte[] with a copy of the current 71 * elements of the ByteArrayInstrument. 72 * 73 * @return Object - a copy of the current value of the elements of the 74 * byte array instrument. The return type is guaranteed 75 * to be of type byte[]. 76 */ 77 public Object getValue() { 78 return byteArrayValue(); 79 } 80 81 /** 82 * Get a copy of the elements of the byte array instrument. 83 * 84 * @return byte[] - a copy of the current value of the elements of the 85 * byte array instrument. 86 */ 87 public byte[] byteArrayValue() { 88 bb.position(0); 89 byte[] b = new byte[bb.limit()]; 90 91 // copy the bytes 92 bb.get(b); 93 94 return b; 95 } 96 97 /** 98 * Get the current value of an element of the byte array instrument. 99 * 100 * @return byte - a copy of the current value of the element at index 101 * {@code index} of the byte array instrument. 102 */ 103 public byte byteAt(int index) { 104 bb.position(index); 105 return bb.get(); 106 } 107 108 /** 109 * Get the maximum length of the byte array for this byte array instrument. 110 * 111 * @return int - the maximum length of the byte array. 112 */ 113 public int getMaximumLength() { 114 return bb.limit(); 115 } 116} 117