зеркало из https://github.com/mozilla/pjs.git
112 строки
2.9 KiB
Java
112 строки
2.9 KiB
Java
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/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil -*-
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*
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* The contents of this file are subject to the Mozilla Public License
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* Version 1.0 (the "License"); you may not use this file except in
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* compliance with the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS"
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* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
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* the License for the specific language governing rights and limitations
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* under the License.
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*
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* The Original Code is the Grendel mail/news client.
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*
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* The Initial Developer of the Original Code is Netscape Communications
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* Corporation. Portions created by Netscape are Copyright (C) 1997
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* Netscape Communications Corporation. All Rights Reserved.
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*/
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package calypso.util;
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import java.lang.Runtime;
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/**
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* A utility class to help track memory usage during development.
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* The interface is simple. Just create the monitor, do your business,
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* and then invoke the done method. <p>
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*
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* The figure for the ammount of memory allocated should be accurate
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* but the number for the ammount of garbage can be off by quite a bit
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* if any garbage collection was done between the monitor's creation
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* and the call to done. <p>
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*
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* Currently, it just prints some stuff to the console. I'd like to
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* extend it so it creates a window and displays it's info in that.
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*
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* @author Thom FillABomb :-)
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*/
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public class MemoryMonitor
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{
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Runtime fSystem;
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long fFreeAtStart,
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fFreeAtEnd,
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fGarbageGenerated;
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String fUserString = null;
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public MemoryMonitor (String monitorDescription)
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{
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fUserString = monitorDescription;
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initialize();
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}
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public MemoryMonitor ()
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{
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initialize();
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}
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protected void initialize ()
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{
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fSystem = Runtime.getRuntime();
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beginMonitor();
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}
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public void done ()
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{
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finishMonitor ();
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System.out.println();
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if (fUserString != null)
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System.out.println (fUserString);
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System.out.println (" Starting Free: " + fFreeAtStart);
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System.out.println (" Ending Free: " + fFreeAtEnd);
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System.out.println (" Memory Delta: " + (fFreeAtStart - fFreeAtEnd));
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System.out.println ("Garbage Generated: " + fGarbageGenerated);
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}
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protected void freeUpMemory ()
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{
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// we might want to tickle Kipp's memory Manager here as well...
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fSystem.runFinalization();
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// might want to sleep here
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fSystem.gc();
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fSystem.gc();
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}
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void beginMonitor ()
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{
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freeUpMemory();
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fFreeAtStart = fSystem.freeMemory();
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}
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void finishMonitor ()
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{
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long totalUsed, minusGarbage;
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totalUsed = fSystem.freeMemory();
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freeUpMemory();
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minusGarbage = fSystem.freeMemory();
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// it would also be interesting to purge the recyclers here and
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// see how much memory they're occupying
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fGarbageGenerated = minusGarbage - totalUsed;
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fFreeAtEnd = minusGarbage;
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}
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}
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