/*
* Copyright 2010 Red Hat, Inc.
* Red Hat licenses this file to you under the Apache License, version
* 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package org.hornetq.core.paging.cursor;
import java.lang.ref.WeakReference;
import java.util.concurrent.atomic.AtomicInteger;
import org.hornetq.api.core.Message;
import org.hornetq.core.logging.Logger;
import org.hornetq.core.paging.PagedMessage;
import org.hornetq.core.server.MessageReference;
import org.hornetq.core.server.Queue;
import org.hornetq.core.server.ServerMessage;
import org.hornetq.core.transaction.Transaction;
/**
* A InternalReference
*
* @author clebert
*
*
*/
public class PagedReferenceImpl implements PagedReference
{
private static final long serialVersionUID = -8640232251318264710L;
private static final Logger log = Logger.getLogger(PagedReferenceImpl.class);
private static final boolean isTrace = log.isTraceEnabled();
private final PagePosition position;
private WeakReference<PagedMessage> message;
private Long deliveryTime = null;
private int persistedCount;
private int messageEstimate;
private AtomicInteger deliveryCount = new AtomicInteger(0);
private final PageSubscription subscription;
public ServerMessage getMessage()
{
return getPagedMessage().getMessage();
}
public synchronized PagedMessage getPagedMessage()
{
PagedMessage returnMessage = message != null ? message.get() : null;
// We only keep a few references on the Queue from paging...
// Besides those references are SoftReferenced on page cache...
// So, this will unlikely be null,
// unless the Queue has stalled for some time after paging
if (returnMessage == null)
{
// reference is gone, we will reconstruct it
returnMessage = subscription.queryMessage(position);
message = new WeakReference<PagedMessage>(returnMessage);
}
return returnMessage;
}
public PagePosition getPosition()
{
return position;
}
public PagedReferenceImpl(final PagePosition position,
final PagedMessage message,
final PageSubscription subscription)
{
this.position = position;
if (message == null)
{
this.messageEstimate = -1;
}
else
{
this.messageEstimate = message.getMessage().getMemoryEstimate();
}
this.message = new WeakReference<PagedMessage>(message);
this.subscription = subscription;
}
public boolean isPaged()
{
return true;
}
public void setPersistedCount(int count)
{
this.persistedCount = count;
}
public int getPersistedCount()
{
return persistedCount;
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#getMessageMemoryEstimate()
*/
public int getMessageMemoryEstimate()
{
if (messageEstimate < 0)
{
messageEstimate = getMessage().getMemoryEstimate();
}
return messageEstimate;
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#copy(org.hornetq.core.server.Queue)
*/
public MessageReference copy(final Queue queue)
{
return new PagedReferenceImpl(this.position, this.getPagedMessage(), this.subscription);
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#getScheduledDeliveryTime()
*/
public long getScheduledDeliveryTime()
{
if (deliveryTime == null)
{
ServerMessage msg = getMessage();
if (msg.containsProperty(Message.HDR_SCHEDULED_DELIVERY_TIME))
{
deliveryTime = getMessage().getLongProperty(Message.HDR_SCHEDULED_DELIVERY_TIME);
}
else
{
deliveryTime = 0l;
}
}
return deliveryTime;
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#setScheduledDeliveryTime(long)
*/
public void setScheduledDeliveryTime(final long scheduledDeliveryTime)
{
deliveryTime = scheduledDeliveryTime;
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#getDeliveryCount()
*/
public int getDeliveryCount()
{
return deliveryCount.get();
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#setDeliveryCount(int)
*/
public void setDeliveryCount(final int deliveryCount)
{
this.deliveryCount.set(deliveryCount);
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#incrementDeliveryCount()
*/
public void incrementDeliveryCount()
{
deliveryCount.incrementAndGet();
if (isTrace)
{
log.trace("++deliveryCount = " + deliveryCount + " for " + this, new Exception ("trace"));
}
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#decrementDeliveryCount()
*/
public void decrementDeliveryCount()
{
deliveryCount.decrementAndGet();
if (isTrace)
{
log.trace("--deliveryCount = " + deliveryCount + " for " + this, new Exception ("trace"));
}
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#getQueue()
*/
public Queue getQueue()
{
return subscription.getQueue();
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#handled()
*/
public void handled()
{
getQueue().referenceHandled();
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#acknowledge()
*/
public void acknowledge() throws Exception
{
subscription.ack(this);
}
/* (non-Javadoc)
* @see org.hornetq.core.server.MessageReference#acknowledge(org.hornetq.core.transaction.Transaction)
*/
public void acknowledge(final Transaction tx) throws Exception
{
subscription.ackTx(tx, this);
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
String msgToString;
try
{
msgToString = getPagedMessage().toString();
}
catch (Throwable e)
{
// in case of an exception because of a missing page, we just want toString to return null
msgToString = "error:" + e.getMessage();
}
return "PagedReferenceImpl [position=" + position +
", message=" +
msgToString +
", deliveryTime=" +
deliveryTime +
", persistedCount=" +
persistedCount +
", deliveryCount=" +
deliveryCount +
", subscription=" +
subscription +
"]";
}
}