/*
*
* 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.queue;
import org.apache.log4j.Logger;
import org.apache.qpid.AMQException;
import org.apache.qpid.framing.AMQBody;
import org.apache.qpid.framing.AMQDataBlock;
import org.apache.qpid.framing.AMQFrame;
import org.apache.qpid.framing.ContentHeaderBody;
import org.apache.qpid.framing.abstraction.ContentChunk;
import org.apache.qpid.framing.abstraction.MessagePublishInfo;
import org.apache.qpid.framing.abstraction.ProtocolVersionMethodConverter;
import org.apache.qpid.server.protocol.AMQProtocolSession;
import org.apache.qpid.server.store.MessageStore;
import org.apache.qpid.server.store.StoreContext;
import org.apache.qpid.server.txn.TransactionalContext;
import java.util.Iterator;
import java.util.concurrent.atomic.AtomicInteger;
/**
* A deliverable message.
*/
public class AMQMessage implements Filterable<AMQException>
{
/** Used for debugging purposes. */
private static final Logger _log = Logger.getLogger(AMQMessage.class);
private final AtomicInteger _referenceCount = new AtomicInteger(1);
private final AMQMessageHandle _messageHandle;
/** Holds the transactional context in which this message is being processed. */
private StoreContext _storeContext;
/** 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 AMQProtocolSession.ProtocolSessionIdentifier _sessionIdentifier;
private static final byte IMMEDIATE_AND_DELIVERED = (byte) (IMMEDIATE | DELIVERED_TO_CONSUMER);
/**
* Used to iterate through all the body frames associated with this message. Will not keep all the data in memory
* therefore is memory-efficient.
*/
private class BodyFrameIterator implements Iterator<AMQDataBlock>
{
private int _channel;
private int _index = -1;
private AMQProtocolSession _protocolSession;
private BodyFrameIterator(AMQProtocolSession protocolSession, int channel)
{
_channel = channel;
_protocolSession = protocolSession;
}
public boolean hasNext()
{
try
{
return _index < (_messageHandle.getBodyCount(getStoreContext()) - 1);
}
catch (AMQException e)
{
_log.error("Unable to get body count: " + e, e);
return false;
}
}
public AMQDataBlock next()
{
try
{
AMQBody cb =
getProtocolVersionMethodConverter().convertToBody(_messageHandle.getContentChunk(getStoreContext(),
++_index));
return new AMQFrame(_channel, cb);
}
catch (AMQException e)
{
// have no choice but to throw a runtime exception
throw new RuntimeException("Error getting content body: " + e, e);
}
}
private ProtocolVersionMethodConverter getProtocolVersionMethodConverter()
{
return _protocolSession.getMethodRegistry().getProtocolVersionMethodConverter();
}
public void remove()
{
throw new UnsupportedOperationException();
}
}
public void clearStoreContext()
{
_storeContext = new StoreContext();
}
public StoreContext getStoreContext()
{
return _storeContext;
}
private class BodyContentIterator implements Iterator<ContentChunk>
{
private int _index = -1;
public boolean hasNext()
{
try
{
return _index < (_messageHandle.getBodyCount(getStoreContext()) - 1);
}
catch (AMQException e)
{
_log.error("Error getting body count: " + e, e);
return false;
}
}
public ContentChunk next()
{
try
{
return _messageHandle.getContentChunk(getStoreContext(), ++_index);
}
catch (AMQException e)
{
throw new RuntimeException("Error getting content body: " + e, e);
}
}
public void remove()
{
throw new UnsupportedOperationException();
}
}
/**
* Used when recovering, i.e. when the message store is creating references to messages. In that case, the normal
* enqueue/routingComplete is not done since the recovery process is responsible for routing the messages to
* queues.
*
* @param messageId
* @param store
* @param factory
*
* @throws AMQException
*/
public AMQMessage(Long messageId, MessageStore store, MessageHandleFactory factory, TransactionalContext txnConext)
throws AMQException
{
_messageHandle = factory.createMessageHandle(messageId, store, true);
_storeContext = txnConext.getStoreContext();
_size = _messageHandle.getBodySize(txnConext.getStoreContext());
}
/**
* Used when recovering, i.e. when the message store is creating references to messages. In that case, the normal
* enqueue/routingComplete is not done since the recovery process is responsible for routing the messages to
* queues.
*
* @param messageHandle
*
* @throws AMQException
*/
public AMQMessage(
AMQMessageHandle messageHandle,
StoreContext storeConext,
MessagePublishInfo info)
throws AMQException
{
_messageHandle = messageHandle;
_storeContext = storeConext;
if(info.isImmediate())
{
_flags |= IMMEDIATE;
}
_size = messageHandle.getBodySize(storeConext);
}
protected AMQMessage(AMQMessage msg) throws AMQException
{
_messageHandle = msg._messageHandle;
_storeContext = msg._storeContext;
_flags = msg._flags;
_size = msg._size;
}
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 Iterator<AMQDataBlock> getBodyFrameIterator(AMQProtocolSession protocolSession, int channel)
{
return new BodyFrameIterator(protocolSession, channel);
}
public Iterator<ContentChunk> getContentBodyIterator()
{
return new BodyContentIterator();
}
public ContentHeaderBody getContentHeaderBody() throws AMQException
{
return _messageHandle.getContentHeaderBody(getStoreContext());
}
public Long getMessageId()
{
return _messageHandle.getMessageId();
}
/**
* 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) <= 1)
{
_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.
*
* @param storeContext
*
* @throws MessageCleanupException when an attempt was made to remove the message from the message store and that
* failed
*/
public void decrementReference(StoreContext storeContext) throws MessageCleanupException
{
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);
try
{
// 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 (_messageHandle != null)
{
_messageHandle.removeMessage(storeContext);
}
}
catch (AMQException e)
{
// to maintain consistency, we revert the count
incrementReference();
throw new MessageCleanupException(getMessageId(), e);
}
}
else
{
if (count < 0)
{
throw new MessageCleanupException("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 boolean isPersistent() throws AMQException
{
return _messageHandle.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 _messageHandle.getMessagePublishInfo(getStoreContext());
}
public boolean isRedelivered()
{
return _messageHandle.isRedelivered();
}
public void setRedelivered(boolean redelivered)
{
_messageHandle.setRedelivered(redelivered);
}
public long getArrivalTime()
{
return _messageHandle.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 AMQMessageHandle getMessageHandle()
{
return _messageHandle;
}
public long getSize()
{
return _size;
}
public Object getPublisherClientInstance()
{
return _sessionIdentifier.getSessionInstance();
}
public Object getPublisherIdentifier()
{
return _sessionIdentifier.getSessionIdentifier();
}
public void setClientIdentifier(final AMQProtocolSession.ProtocolSessionIdentifier sessionIdentifier)
{
_sessionIdentifier = sessionIdentifier;
}
public String toString()
{
// return "Message[" + debugIdentity() + "]: " + _messageId + "; ref count: " + _referenceCount + "; taken : " +
// _taken + " by :" + _takenBySubcription;
return "Message[" + debugIdentity() + "]: " + getMessageId() + "; ref count: " + _referenceCount;
}
}