com.sun.gjc.util.SQLTraceCache Maven / Gradle / Ivy
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// Portions Copyright [2016-2017] [Payara Foundation and/or its affiliates]
package com.sun.gjc.util;
import com.sun.logging.LogDomains;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Timer;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Base class for Sql Tracing Caches used to store SQL statements used by applications.
*
* @author Shalini M
*/
public abstract class SQLTraceCache {
//Maximum size of the cache.
protected int numTopQueriesToReport = 10;
protected long timeToKeepQueries = 60000;
protected final String poolName;
protected ConcurrentSkipListMap cache;
private SQLTraceTimerTask sqlTraceTimerTask;
protected final static Logger _logger = LogDomains.getLogger(SQLTraceCache.class,
LogDomains.RSR_LOGGER);
protected static final String LINE_BREAK = "%%%EOL%%%";
public SQLTraceCache(String poolName, int maxSize, long timeToKeepQueries) {
this.cache = new ConcurrentSkipListMap<>();
this.poolName = poolName;
this.numTopQueriesToReport = maxSize;
this.timeToKeepQueries = timeToKeepQueries * 60 * 1000;
}
public Collection getSqlTraceList() {
return cache.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 && timeToKeepQueries > 0) {
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
*/
public abstract void checkAndUpdateCache(SQLTrace 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() {
List sqlTraceList = new ArrayList(cache.values());
Collections.sort(sqlTraceList, SQLTrace.SQLTraceFrequencyComparator);
int elementCount = sqlTraceList.size();
while (elementCount > numTopQueriesToReport) {
SQLTrace sqlTrace = sqlTraceList.get(elementCount - 1);
cache.remove(sqlTrace.getQueryName());
sqlTraceList.remove(sqlTrace);
elementCount --;
}
}
}