/******************************************************************************* | |
* Copyright (c) 1998, 2013 Oracle and/or its affiliates. All rights reserved. | |
* This program and the accompanying materials are made available under the | |
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 | |
* which accompanies this distribution. | |
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html | |
* and the Eclipse Distribution License is available at | |
* http://www.eclipse.org/org/documents/edl-v10.php. | |
* | |
* Contributors: | |
* Oracle - initial API and implementation from Oracle TopLink | |
******************************************************************************/ | |
package org.eclipse.persistence.tools.profiler; | |
import java.util.*; | |
/** | |
* <p><b>Purpose</b>: | |
* Provide a very simple low overhead means for measuring fetch group field usage. | |
* This can be useful for performance analysis in a complex system. | |
* This monitor is enabled through the System property "org.eclipse.persistence.fetchgroupmonitor=true". | |
* It dumps the attribute used for a class every time a new attribute is accessed. | |
* | |
* @author James Sutherland | |
* @since TopLink 10.1.3.2 | |
*/ | |
public class FetchGroupMonitor { | |
public static Hashtable fetchedAttributes = new Hashtable(); | |
public static Boolean shouldMonitor; | |
public static boolean shouldMonitor() { | |
if (shouldMonitor == null) { | |
shouldMonitor = Boolean.FALSE; | |
String property = System.getProperty("org.eclipse.persistence.fetchgroupmonitor"); | |
if ((property != null) && (property.toUpperCase().equals("TRUE"))) { | |
shouldMonitor = Boolean.TRUE; | |
} | |
} | |
return shouldMonitor.booleanValue(); | |
} | |
public static void recordFetchedAttribute(Class domainClass, String attributeName) { | |
if (! shouldMonitor()) { | |
return; | |
} | |
synchronized (fetchedAttributes) { | |
Set classesFetchedAttributes = (Set) fetchedAttributes.get(domainClass); | |
if (classesFetchedAttributes == null) { | |
classesFetchedAttributes = new HashSet(); | |
fetchedAttributes.put(domainClass, classesFetchedAttributes); | |
} | |
if (!classesFetchedAttributes.contains(attributeName)) { | |
classesFetchedAttributes.add(attributeName); | |
System.out.println("Fetched attributes: " + domainClass + " - " + classesFetchedAttributes); | |
} | |
} | |
} | |
} |