org.eclipse.persistence.tools.profiler.FetchGroupMonitor Maven / Gradle / Ivy
/*******************************************************************************
* 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.*;
/**
* Purpose:
* 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);
}
}
}
}