/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2011, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.stat.internal;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.hibernate.cache.spi.CacheKey;
import org.hibernate.cache.spi.Region;
import org.hibernate.stat.NaturalIdCacheStatistics;
/**
* NaturalId cache statistics of a specific region
*
* @author Eric Dalquist
*/
public class ConcurrentNaturalIdCacheStatisticsImpl extends CategorizedStatistics implements NaturalIdCacheStatistics {
private static final long serialVersionUID = 1L;
private final transient Region region;
private final AtomicLong hitCount = new AtomicLong();
private final AtomicLong missCount = new AtomicLong();
private final AtomicLong putCount = new AtomicLong();
private final AtomicLong executionCount = new AtomicLong();
private final AtomicLong executionMaxTime = new AtomicLong();
private final AtomicLong executionMinTime = new AtomicLong( Long.MAX_VALUE );
private final AtomicLong totalExecutionTime = new AtomicLong();
private final Lock readLock;
private final Lock writeLock;
{
final ReadWriteLock lock = new ReentrantReadWriteLock();
this.readLock = lock.readLock();
this.writeLock = lock.writeLock();
}
ConcurrentNaturalIdCacheStatisticsImpl(Region region) {
super( region.getName() );
this.region = region;
}
@Override
public long getHitCount() {
return this.hitCount.get();
}
@Override
public long getMissCount() {
return this.missCount.get();
}
@Override
public long getPutCount() {
return this.putCount.get();
}
/**
* queries executed to the DB
*/
@Override
public long getExecutionCount() {
return this.executionCount.get();
}
/**
* average time in ms taken by the excution of this query onto the DB
*/
@Override
public long getExecutionAvgTime() {
// We write lock here to be sure that we always calculate the average time
// with all updates from the executed applied: executionCount and totalExecutionTime
// both used in the calculation
this.writeLock.lock();
try {
long avgExecutionTime = 0;
if ( this.executionCount.get() > 0 ) {
avgExecutionTime = this.totalExecutionTime.get() / this.executionCount.get();
}
return avgExecutionTime;
}
finally {
this.writeLock.unlock();
}
}
/**
* max time in ms taken by the excution of this query onto the DB
*/
@Override
public long getExecutionMaxTime() {
return this.executionMaxTime.get();
}
/**
* min time in ms taken by the excution of this query onto the DB
*/
@Override
public long getExecutionMinTime() {
return this.executionMinTime.get();
}
@Override
public long getElementCountInMemory() {
return this.region.getElementCountInMemory();
}
@Override
public long getElementCountOnDisk() {
return this.region.getElementCountOnDisk();
}
@Override
public long getSizeInMemory() {
return this.region.getSizeInMemory();
}
@Override
public Map getEntries() {
final Map map = new HashMap();
final Iterator iter = this.region.toMap().entrySet().iterator();
while ( iter.hasNext() ) {
final Map.Entry me = (Map.Entry) iter.next();
map.put( ( (CacheKey) me.getKey() ).getKey(), me.getValue() );
}
return map;
}
@Override
public String toString() {
final StringBuilder buf = new StringBuilder()
.append( "NaturalIdCacheStatistics" )
.append( "[hitCount=" ).append( this.hitCount )
.append( ",missCount=" ).append( this.missCount )
.append( ",putCount=" ).append( this.putCount )
.append( ",executionCount=" ).append( this.executionCount )
.append( ",executionAvgTime=" ).append( this.getExecutionAvgTime() )
.append( ",executionMinTime=" ).append( this.executionMinTime )
.append( ",executionMaxTime=" ).append( this.executionMaxTime );
// not sure if this would ever be null but wanted to be careful
if ( this.region != null ) {
buf.append( ",elementCountInMemory=" ).append( this.getElementCountInMemory() )
.append( ",elementCountOnDisk=" ).append( this.getElementCountOnDisk() )
.append( ",sizeInMemory=" ).append( this.getSizeInMemory() );
}
buf.append( ']' );
return buf.toString();
}
void incrementHitCount() {
this.hitCount.getAndIncrement();
}
void incrementMissCount() {
this.missCount.getAndIncrement();
}
void incrementPutCount() {
this.putCount.getAndIncrement();
}
void queryExecuted(long time) {
// read lock is enough, concurrent updates are supported by the underlying type AtomicLong
// this only guards executed(long, long) to be called, when another thread is executing getExecutionAvgTime()
this.readLock.lock();
try {
// Less chances for a context switch
for ( long old = this.executionMinTime.get(); time < old && !this.executionMinTime.compareAndSet( old, time ); old = this.executionMinTime.get() ) {;}
for ( long old = this.executionMaxTime.get(); time > old && !this.executionMaxTime.compareAndSet( old, time ); old = this.executionMaxTime.get() ) {;}
this.executionCount.getAndIncrement();
this.totalExecutionTime.addAndGet( time );
}
finally {
this.readLock.unlock();
}
}
}