/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.qpid.server.message;
import org.apache.log4j.Logger;
import org.apache.qpid.AMQException;
import org.apache.qpid.framing.ContentHeaderBody;
import org.apache.qpid.framing.abstraction.MessagePublishInfo;
import org.apache.qpid.server.AMQChannel;
import org.apache.qpid.server.store.StoredMessage;
import org.apache.qpid.server.configuration.SessionConfig;
import org.apache.qpid.server.queue.AMQQueue;
import java.util.concurrent.atomic.AtomicInteger;
import java.lang.ref.WeakReference;
import java.nio.ByteBuffer;
/**
* A deliverable message.
*/
public class AMQMessage implements ServerMessage
{
/** Used for debugging purposes. */
private static final Logger _log = Logger.getLogger(AMQMessage.class);
private final AtomicInteger _referenceCount = new AtomicInteger(0);
/** Flag to indicate that this message requires 'immediate' delivery. */
private static final byte IMMEDIATE = 0x01;
/**
* Flag to indicate whether this message has been delivered to a consumer. Used in implementing return functionality
* for messages published with the 'immediate' flag.
*/
private static final byte DELIVERED_TO_CONSUMER = 0x02;
private byte _flags = 0;
private long _expiration;
private final long _size;
private Object _sessionIdentifier;
private static final byte IMMEDIATE_AND_DELIVERED = (byte) (IMMEDIATE | DELIVERED_TO_CONSUMER);
private final StoredMessage<MessageMetaData> _handle;
WeakReference<AMQChannel> _channelRef;
public AMQMessage(StoredMessage<MessageMetaData> handle)
{
this(handle, null);
}
public AMQMessage(StoredMessage<MessageMetaData> handle, WeakReference<AMQChannel> channelRef)
{
_handle = handle;
final MessageMetaData metaData = handle.getMetaData();
_size = metaData.getContentSize();
final MessagePublishInfo messagePublishInfo = metaData.getMessagePublishInfo();
if(messagePublishInfo.isImmediate())
{
_flags |= IMMEDIATE;
}
_channelRef = channelRef;
}
public String debugIdentity()
{
return "(HC:" + System.identityHashCode(this) + " ID:" + getMessageId() + " Ref:" + _referenceCount.get() + ")";
}
public void setExpiration(final long expiration)
{
_expiration = expiration;
}
public boolean isReferenced()
{
return _referenceCount.get() > 0;
}
public MessageMetaData getMessageMetaData()
{
return _handle.getMetaData();
}
public ContentHeaderBody getContentHeaderBody() throws AMQException
{
return getMessageMetaData().getContentHeaderBody();
}
public Long getMessageId()
{
return _handle.getMessageNumber();
}
/**
* Creates a long-lived reference to this message, and increments the count of such references, as an atomic
* operation.
*/
public AMQMessage takeReference()
{
incrementReference(); // _referenceCount.incrementAndGet();
return this;
}
public boolean incrementReference()
{
return incrementReference(1);
}
/* Threadsafe. Increment the reference count on the message. */
public boolean incrementReference(int count)
{
if(_referenceCount.addAndGet(count) <= 0)
{
_referenceCount.addAndGet(-count);
return false;
}
else
{
return true;
}
}
/**
* Threadsafe. This will decrement the reference count and when it reaches zero will remove the message from the
* message store.
*
*
* @throws org.apache.qpid.server.queue.MessageCleanupException when an attempt was made to remove the message from the message store and that
* failed
*/
public void decrementReference()
{
int count = _referenceCount.decrementAndGet();
// note that the operation of decrementing the reference count and then removing the message does not
// have to be atomic since the ref count starts at 1 and the exchange itself decrements that after
// the message has been passed to all queues. i.e. we are
// not relying on the all the increments having taken place before the delivery manager decrements.
if (count == 0)
{
// set the reference count way below 0 so that we can detect that the message has been deleted
// this is to guard against the message being spontaneously recreated (from the mgmt console)
// by copying from other queues at the same time as it is being removed.
_referenceCount.set(Integer.MIN_VALUE/2);
// must check if the handle is null since there may be cases where we decide to throw away a message
// and the handle has not yet been constructed
if (_handle != null)
{
_handle.remove();
}
}
else
{
if (count < 0)
{
throw new RuntimeException("Reference count for message id " + debugIdentity()
+ " has gone below 0.");
}
}
}
/**
* Called selectors to determin if the message has already been sent
*
* @return _deliveredToConsumer
*/
public boolean getDeliveredToConsumer()
{
return (_flags & DELIVERED_TO_CONSUMER) != 0;
}
public String getRoutingKey()
{
// TODO
return null;
}
public AMQMessageHeader getMessageHeader()
{
return getMessageMetaData().getMessageHeader();
}
public boolean isPersistent()
{
return getMessageMetaData().isPersistent();
}
/**
* Called to enforce the 'immediate' flag.
*
* @returns true if the message is marked for immediate delivery but has not been marked as delivered
* to a consumer
*/
public boolean immediateAndNotDelivered()
{
return (_flags & IMMEDIATE_AND_DELIVERED) == IMMEDIATE;
}
public MessagePublishInfo getMessagePublishInfo() throws AMQException
{
return getMessageMetaData().getMessagePublishInfo();
}
public long getArrivalTime()
{
return getMessageMetaData().getArrivalTime();
}
/**
* Checks to see if the message has expired. If it has the message is dequeued.
*
* @param queue The queue to check the expiration against. (Currently not used)
*
* @return true if the message has expire
*
* @throws AMQException
*/
public boolean expired(AMQQueue queue) throws AMQException
{
if (_expiration != 0L)
{
long now = System.currentTimeMillis();
return (now > _expiration);
}
return false;
}
/**
* Called when this message is delivered to a consumer. (used to implement the 'immediate' flag functionality).
* And for selector efficiency.
*/
public void setDeliveredToConsumer()
{
_flags |= DELIVERED_TO_CONSUMER;
}
public long getSize()
{
return _size;
}
public boolean isImmediate()
{
return (_flags & IMMEDIATE) == IMMEDIATE;
}
public long getExpiration()
{
return _expiration;
}
public MessageReference newReference()
{
return new AMQMessageReference(this);
}
public Long getMessageNumber()
{
return getMessageId();
}
public Object getPublisherIdentifier()
{
//todo store sessionIdentifier/client id with message in store
//Currently the _sessionIdentifier will be null if the message has been
// restored from a message Store
return _sessionIdentifier;
}
public void setClientIdentifier(final Object sessionIdentifier)
{
_sessionIdentifier = sessionIdentifier;
}
public String toString()
{
// return "Message[" + debugIdentity() + "]: " + _messageId + "; ref count: " + _referenceCount + "; taken : " +
// _taken + " by :" + _takenBySubcription;
return "Message[" + debugIdentity() + "]: " + getMessageId() + "; ref count: " + _referenceCount;
}
public int getContent(ByteBuffer buf, int offset)
{
return _handle.getContent(offset, buf);
}
public StoredMessage<MessageMetaData> getStoredMessage()
{
return _handle;
}
public SessionConfig getSessionConfig()
{
return _channelRef == null ? null : ((SessionConfig) _channelRef.get());
}
}