/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2010 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
// Portions Copyright [2016] [Payara Foundation and/or its affiliates]
package com.sun.gjc.util;
import com.sun.logging.LogDomains;
import java.util.Collection;
import java.util.Iterator;
import java.util.Timer;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Maintains the Sql Tracing Cache used to store SQL statements used by the
* applications. This is used by the JDBCRA monitoring to display the most
* frequently used queries by applications.
*
* @author Shalini M
*/
public class SQLTraceCache {
//List of sql trace objects
private final ConcurrentSkipListMap<SQLTrace,SQLTrace> list;
//Maximum size of the cache.
private int numTopQueriesToReport = 10;
private long timeToKeepQueries = 60 * 1000;
private SQLTraceTimerTask sqlTraceTimerTask;
private final String poolName;
private final String appName;
private final String moduleName;
private final static Logger _logger = LogDomains.getLogger(SQLTraceCache.class,
LogDomains.RSR_LOGGER);
private static final String LINE_BREAK = "%%%EOL%%%";
public SQLTraceCache(String poolName, String appName, String moduleName, int maxSize, long timeToKeepQueries) {
this.poolName = poolName;
this.appName = appName;
this.moduleName = moduleName;
this.numTopQueriesToReport = maxSize;
list = new ConcurrentSkipListMap<>();
this.timeToKeepQueries = timeToKeepQueries * 60 * 1000;
}
public Collection<SQLTrace> getSqlTraceList() {
return list.keySet();
}
public String getPoolName() {
return poolName;
}
/**
* Schedule timer to perform purgeEntries on the cache after the
* specified timeToKeepQueries delay and period.
* @param timer
*/
public void scheduleTimerTask(Timer timer) {
if(sqlTraceTimerTask != null) {
sqlTraceTimerTask.cancel();
sqlTraceTimerTask = null;
}
sqlTraceTimerTask = initializeTimerTask();
if(timer != null) {
timer.scheduleAtFixedRate(sqlTraceTimerTask, timeToKeepQueries, timeToKeepQueries);
}
if(_logger.isLoggable(Level.FINEST)) {
_logger.finest("Scheduled Sql Trace Caching timer task");
}
}
/**
* Cancel the timer task used to perform a purgeEntries on the cache.
*/
public synchronized void cancelTimerTask() {
if(_logger.isLoggable(Level.FINEST)) {
_logger.finest("Cancelling Sql Trace Caching timer task");
}
if (sqlTraceTimerTask != null) {
sqlTraceTimerTask.cancel();
}
sqlTraceTimerTask = null;
}
/**
* Instantiate the timer task used to perform a purgeEntries on the cache
*
* @return SQLTraceTimerTask
*/
private SQLTraceTimerTask initializeTimerTask() {
if(_logger.isLoggable(Level.FINEST)) {
_logger.finest("Initializing Sql Trace Caching timer task");
}
return new SQLTraceTimerTask(this);
}
/**
* Request for adding a sql query in the form of SQLTrace to this cache.
* If the query is already found
* in the list, the number of times it is executed is incremented by one
* along with the timestamp.
* If the query is a new one, it is added to the list.
*
* @param cacheObj
* @return
*/
public void checkAndUpdateCache(SQLTrace cacheObj) {
if (cacheObj != null) {
SQLTrace cache = list.get(cacheObj);
if (cache != null) {
//If already found in the cache
//equals is invoked here and hence comparison based on query name is done
//Get the object at the index to update the numExecutions
cache.setNumExecutions(cache.getNumExecutions() + 1);
cache.setLastUsageTime(System.currentTimeMillis());
} else {
list.put(cacheObj,cacheObj);
}
}
}
/**
* Entries are removed from the list after sorting
* them in the least frequently used order. Only numTopQueriesToReport number of
* entries are maintained in the list after the purgeEntries.
*/
public void purgeEntries() {
Iterator i = list.keySet().descendingIterator();
int elementCount = list.size(); // avoid using size in the loop as expensive in time
while (i.hasNext() && elementCount > numTopQueriesToReport) {
SQLTrace cacheObj = (SQLTrace) i.next();
if(_logger.isLoggable(Level.FINEST)) {
_logger.finest("removing sql=" + cacheObj.getQueryName());
}
i.remove();
elementCount--;
}
}
/**
* Returns the String representation of the list of traced sql queries
* ordered by the number most frequently used, followed by the usage
* timestamp. Only the top 'n' queries represented by the numTopQueriesToReport are
* chosen for display.
*
* @return string representation of the list of sql queries sorted
*/
public String getTopQueries() {
purgeEntries();
StringBuilder sb = new StringBuilder();
for(SQLTrace cache : list.keySet()) {
sb.append(LINE_BREAK);
sb.append(cache.getQueryName());
sb.append(" executions: ").append(cache.getNumExecutions());
}
return sb.toString();
}
}