ch.epfl.lsr.apex.connection
Class APEXConnection

java.lang.Object
  ch.epfl.lsr.apex.connection.APEXConnection

All Implemented Interfaces:

Runnable

Direct Known Subclasses:

APEXEdgeConnection, APEXMeshConnection

public abstract class APEXConnection

extends Object

implements Runnable

An APEXConnection is a connection thread that takes messages to send on this connection in a linked list (file) and sends them on after another to the destination.

The APEXConnection, due to its abstract property, must be redefined as either an APEXMeshConnection for relay-relay connections or an APEXEdgeConnection for relay-endpoint connections.

Author:

Marc Stoecklin

See Also:

APEXMeshConnection, APEXEdgeConnection

Field Summary

protected Hashtable	authenticatedAs A table of authenticated names of this entity on this connection
static int	CHANNEL_ESTABLISHED
protected Object	channelID A unique channel identifier for this connection
static int	CONNECTION_INITIATION
protected boolean	connectionEstablished indicates the state of the connection
protected APEXConnectionThread	connectionThread The actual connection runs in a connection thread for this connection
protected static Hashtable	currentConnections A static table for all currently running connections.
protected String	entity The general entity name for this connection (relay or endpoint name)
protected Hashtable	internalIDs A table of internal identifiers to map back attached endpoints or bound relays to correspondent transaction identifiers
protected static Hashtable	knownChannels A static table for already known channels to link different attaching endpoints or relays (for a relay) and different domains (for an endpoint) on the same connection.
protected APEXManager	manager The associated manager for call-backs
protected LinkedList	messageFile A message file (channel) FIFO
protected long	pollingIntervall The polling interval for connection control: 10 sec
protected APEXProfile	profile The profile associated to this connection
protected boolean	running indicates the state thread
protected int	task the state of the connection
protected Integer	transID The transaction identifier counter for this connection
protected int	trialNb Attempt counter on reconnection

Constructor Summary

APEXConnection()

Method Summary

protected void	addFirstMessage(APEXMessage m) Adds a message to the first position of the FIFO message file.
protected void	addMessage(APEXMessage m) Adds a message to the FIFO message file.
protected abstract void	channelEstablished() Is called by the connection thread if an APEX channel is successfully established - allows to update the status of the connection.
protected void	clearMessageFile() Flushes the whole message file irrevocable.
Object	getChannelID() Returns the channel identifier associated to this connection.
protected APEXMessage	getMessage() Blocking method which is called by the connection thread in order to get a new message to send.
int	getUniqueTransID() Returns a unique transaction identifier for this connection.
protected abstract void	handleReply(Message replyMessage, APEXMessage message) Handles a received reply message to a correspondent (sent) APEX message (attach, bind, terminate, or data).
protected abstract boolean	isAuthenticated(APEXDataMessage message) Returns a boolean which depends if the message is authentcated to be sent or not to the hop (either attached or bound).
protected abstract void	messageNotSent(APEXMessage message) Is called by the connection thread if the session is down an the message has not been sent.
protected void	newAttachmentOrBinding() Is called on a new attachment or binding in order to release blocked connection threads in the getMessage table.
protected abstract void	noConnectionEstablished() Is called by the connection thread if no connection is established and initiates correspondent actions (according the connection type and the underlying manager).
protected abstract void	requestedChannelNotStarted() Is called by the connection thread if no APEX channel is established and initiates correspondent actions (according the connection type and the underlying manager).
void	updateTransID(int aTransID) Updates the internal transID counter if the opposite hop used a new transaction identifier.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Runnable

run

Field Detail

CONNECTION_INITIATION

public static final int CONNECTION_INITIATION

See Also:

Constant Field Values

CHANNEL_ESTABLISHED

public static final int CHANNEL_ESTABLISHED

See Also:

Constant Field Values

currentConnections

protected static Hashtable currentConnections

A static table for all currently running connections.

A connection is mapped with the domain part of its opposite entity.

knownChannels

protected static Hashtable knownChannels

A static table for already known channels to link different attaching endpoints or relays (for a relay) and different domains (for an endpoint) on the same connection.

trialNb

protected int trialNb

Attempt counter on reconnection

running

protected boolean running

indicates the state thread

task

protected int task

the state of the connection

manager

protected APEXManager manager

The associated manager for call-backs

authenticatedAs

protected Hashtable authenticatedAs

A table of authenticated names of this entity on this connection

messageFile

protected LinkedList messageFile

A message file (channel) FIFO

connectionThread

protected APEXConnectionThread connectionThread

The actual connection runs in a connection thread for this connection

entity

protected String entity

The general entity name for this connection (relay or endpoint name)

profile

protected APEXProfile profile

The profile associated to this connection

internalIDs

protected Hashtable internalIDs

A table of internal identifiers to map back attached endpoints or bound relays to correspondent transaction identifiers

channelID

protected Object channelID

A unique channel identifier for this connection

connectionEstablished

protected boolean connectionEstablished

indicates the state of the connection

pollingIntervall

protected long pollingIntervall

The polling interval for connection control: 10 sec

transID

protected Integer transID

The transaction identifier counter for this connection

Constructor Detail

APEXConnection

public APEXConnection()

Method Detail

handleReply

protected abstract void handleReply(Message replyMessage,
                                    APEXMessage message)

Handles a received reply message to a correspondent (sent) APEX message (attach, bind, terminate, or data).

Parameters:

replyMessage - The received reply message

message - The sent APEX message

messageNotSent

protected abstract void messageNotSent(APEXMessage message)

Is called by the connection thread if the session is down an the message has not been sent.

Dependent on the underlying manager and the connection type (edge or mesh), this method either tries to reconnect or calls the discardMessage method of its manager.

Parameters:

message - The unsent message

noConnectionEstablished

protected abstract void noConnectionEstablished()

Is called by the connection thread if no connection is established and initiates correspondent actions (according the connection type and the underlying manager).

requestedChannelNotStarted

protected abstract void requestedChannelNotStarted()

Is called by the connection thread if no APEX channel is established and initiates correspondent actions (according the connection type and the underlying manager).

channelEstablished

protected abstract void channelEstablished()

Is called by the connection thread if an APEX channel is successfully established - allows to update the status of the connection.

isAuthenticated

protected abstract boolean isAuthenticated(APEXDataMessage message)

Returns a boolean which depends if the message is authentcated to be sent or not to the hop (either attached or bound).

getChannelID

public Object getChannelID()

Returns the channel identifier associated to this connection.

Returns:

The channel identifier

getUniqueTransID

public int getUniqueTransID()

Returns a unique transaction identifier for this connection. This method is synchronized on the internal transID.

Returns:

A unique transaction identifier

updateTransID

public void updateTransID(int aTransID)

Updates the internal transID counter if the opposite hop used a new transaction identifier.

Parameters:

aTransID - The transID used by the opposite hop

getMessage

protected APEXMessage getMessage()

Blocking method which is called by the connection thread in order to get a new message to send.

Returns:

An message which has to be sent by a connection thread

addFirstMessage

protected void addFirstMessage(APEXMessage m)

Adds a message to the first position of the FIFO message file.

Parameters:

m - The message to add

addMessage

protected void addMessage(APEXMessage m)

Adds a message to the FIFO message file.

Parameters:

m - The message to add

clearMessageFile

protected void clearMessageFile()

Flushes the whole message file irrevocable.

newAttachmentOrBinding

protected void newAttachmentOrBinding()

Is called on a new attachment or binding in order to release blocked connection threads in the getMessage table. (Note: a connection thread is blocked no message is authenticated to be sent according the attach / bind status)