Package fr.dyade.aaa.agent

Class MessageSoftList

java.lang.Object

fr.dyade.aaa.agent.MessageSoftList

public class MessageSoftList
extends Object

This class holds a list of Message, waiting to be sent. After sending one message it is marked as sent, which means it is kept until its acknowledgment. Once acknowledged, the message is deleted.
This list can hold an acknowledgment message, which is always the first one to be sent if present.
If the list is marked as persistent, messages are encapsulated by MessageSoftRef in order to be garbaged from memory if necessary.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	MessageSoftList.MessageComparator	A comparator to keep list sorted by message stamp.
(package private) static class	MessageSoftList.MessageSoftComparator	A comparator to keep list sorted by message stamp when using soft references.
private static class	MessageSoftList.MessageSoftIterator	An iterator returning the messages when going through a collection of MessageSoftRef.

Field Summary

Fields

Modifier and Type	Field	Description
private Message	ack	Current ack message which will be sent in priority.
private static boolean	DEBUG
private Logger	logger	Logger for the instance.
private SortedSet	msgSentlist	The list of sent messages waiting to be acknowledged.
private SortedSet	msgToSendlist	The list of messages waiting to be sent.
private boolean	persistent	Tells if messages are persisted on disk and can be garbaged from memory.

Constructor Summary

Constructors

Constructor	Description
MessageSoftList(String name, boolean persistent)

Method Summary

Modifier and Type	Method	Description
void	addMessage(Message msg)	Adds a message at the end of the list.
void	deleteMessagesUpTo(int stamp)	Iterates over messages waiting for an acknowledge to delete the ones which have a stamp inferior or equal to the given one.
Message	getAck()	Returns the acknowledge waiting to be sent if present.
Message	getFirst()	Returns the first non expired message waiting to be sent.
private void	removeExpired(Message msg)	Removes the expired message, if needed an ExpiredNot is sent to the deadNotificationAgentId specified.
private void	removeExpired(MessageSoftRef msgRef)	Removes the expired message, if needed an ExpiredNot is sent to the deadNotificationAgentId specified.
void	reset()	Resets all messages waiting for an acknowledge: they are placed back at the beginning of the list respecting their stamp order. Furthermore, expired messages are removed from the list.
private Message	selectFirst()
int	sentSize()	Returns the number of messages waiting for an ack.
void	setAck(Message ack)	Sets the next ack to send.
void	setSent(Message msg)	Mark specified message as sent (ie waiting for an ack).
Iterator	toSendIterator()	Returns an iterator over the messages waiting to be sent.
int	toSendSize()	Returns the number of messages waiting to be sent.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEBUG

private static final boolean DEBUG

logger

private Logger logger

Logger for the instance.

ack

private Message ack

Current ack message which will be sent in priority.

msgToSendlist

private SortedSet msgToSendlist

The list of messages waiting to be sent.

msgSentlist

private SortedSet msgSentlist

The list of sent messages waiting to be acknowledged.

persistent

private final boolean persistent

Tells if messages are persisted on disk and can be garbaged from memory.

Constructor Detail

MessageSoftList

public MessageSoftList(String name,
                       boolean persistent)

Method Detail

addMessage

public void addMessage(Message msg)

Adds a message at the end of the list. Use setAck(Message) if you want to add an ack to the list.

Parameters:

msg - the message to add.

getAck

public Message getAck()

Returns the acknowledge waiting to be sent if present.

Returns:

current acknowledge waiting to be sent, or null if there is none.

getFirst

public Message getFirst()

Returns the first non expired message waiting to be sent. It can be an acknowledge.

Returns:

the next message to send or null if there is none.

selectFirst

private Message selectFirst()

removeExpired

private void removeExpired(MessageSoftRef msgRef)

Removes the expired message, if needed an ExpiredNot is sent to the deadNotificationAgentId specified.

Parameters:

msgRef - The message to remove.

removeExpired

private void removeExpired(Message msg)

Removes the expired message, if needed an ExpiredNot is sent to the deadNotificationAgentId specified.

Parameters:

msg - The message to remove.

deleteMessagesUpTo

public void deleteMessagesUpTo(int stamp)
                        throws IOException

Iterates over messages waiting for an acknowledge to delete the ones which have a stamp inferior or equal to the given one.

Parameters:

stamp - the stamp of the last message acked.

Throws:

IOException - an error occurs.

setAck

public void setAck(Message ack)

Sets the next ack to send.

Parameters:

ack - the acknowledge to send.

toSendIterator

public Iterator toSendIterator()

Returns an iterator over the messages waiting to be sent.

Returns:

an iterator over the messages waiting to be sent.

toString

public String toString()

Overrides:

toString in class Object

reset

public void reset()

Resets all messages waiting for an acknowledge: they are placed back at the beginning of the list respecting their stamp order.
Furthermore, expired messages are removed from the list.

toSendSize

public int toSendSize()

Returns the number of messages waiting to be sent.

Returns:

the number of messages waiting to be sent.

setSent

public void setSent(Message msg)

Mark specified message as sent (ie waiting for an ack). The given message must be the next one to be sent, returned by getFirst().

Parameters:

msg - the message which have been sent.

sentSize

public int sentSize()

Returns the number of messages waiting for an ack.

Returns:

the number of messages waiting for an ack.