core
Class Connection

java.lang.Object
  core.Connection

Direct Known Subclasses:

CBRConnection, VBRConnection

public abstract class Connection
extends java.lang.Object

A connection between two DTN nodes.

Field Summary

protected int	bytesTransferred how many bytes this connection has transferred
protected NetworkInterface	fromInterface
protected DTNHost	fromNode
protected DTNHost	msgFromNode
protected Message	msgOnFly
protected NetworkInterface	toInterface
protected DTNHost	toNode

Constructor Summary

Connection(DTNHost fromNode, NetworkInterface fromInterface, DTNHost toNode, NetworkInterface toInterface)
Creates a new connection between nodes and sets the connection state to "up".

Method Summary

void	abortTransfer() Aborts the transfer of the currently transferred message.
protected void	clearMsgOnFly() Clears the message that is currently being transferred.
void	finalizeTransfer() Finalizes the transfer of the currently transferred message.
Message	getMessage() Gets the message that this connection is currently transferring.
NetworkInterface	getOtherInterface(NetworkInterface i) Returns the interface in the other end of the connection
DTNHost	getOtherNode(DTNHost node) Returns the node in the other end of the connection
abstract int	getRemainingByteCount() Returns the amount of bytes to be transferred before ongoing transfer is ready or 0 if there's no ongoing transfer or it has finished already
abstract double	getSpeed() Gets the current connection speed
int	getTotalBytesTransferred() Returns the total amount of bytes this connection has transferred so far (including all transfers).
boolean	isInitiator(DTNHost node) Returns true if the given node is the initiator of the connection, false otherwise
abstract boolean	isMessageTransferred() Returns true if the current message transfer is done
boolean	isReadyForTransfer() Returns true if the connection is ready to transfer a message (connection is up and there is no message being transferred).
boolean	isUp() Returns true if the connection is up
void	setUpState(boolean state) Sets the state of the connection.
abstract int	startTransfer(DTNHost from, Message m) Sets a message that this connection is currently transferring.
java.lang.String	toString() Returns a String presentation of the connection.
void	update() Calculate the current transmission speed from the information given by the interfaces, and calculate the missing data amount.

Methods inherited from class java.lang.Object

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

Field Detail

toNode

protected DTNHost toNode

toInterface

protected NetworkInterface toInterface

fromNode

protected DTNHost fromNode

fromInterface

protected NetworkInterface fromInterface

msgFromNode

protected DTNHost msgFromNode

msgOnFly

protected Message msgOnFly

bytesTransferred

protected int bytesTransferred

how many bytes this connection has transferred

Constructor Detail

Connection

public Connection(DTNHost fromNode,
                  NetworkInterface fromInterface,
                  DTNHost toNode,
                  NetworkInterface toInterface)

Creates a new connection between nodes and sets the connection state to "up".

Parameters:

fromNode - The node that initiated the connection

fromInterface - The interface that initiated the connection

toNode - The node in the other side of the connection

toInterface - The interface in the other side of the connection

Method Detail

isUp

public boolean isUp()

Returns true if the connection is up

Returns:

state of the connection

isInitiator

public boolean isInitiator(DTNHost node)

Returns true if the given node is the initiator of the connection, false otherwise

Parameters:

node - The node to check

Returns:

true if the given node is the initiator of the connection

setUpState

public void setUpState(boolean state)

Sets the state of the connection.

Parameters:

state - True if the connection is up, false if not

startTransfer

public abstract int startTransfer(DTNHost from,
                                  Message m)

Sets a message that this connection is currently transferring. If message passing is controlled by external events, this method is not needed (but then e.g. finalizeTransfer() and isMessageTransferred() will not work either). Only a one message at a time can be transferred using one connection.

Parameters:

m - The message

Returns:

The value returned by MessageRouter.receiveMessage(Message, DTNHost)

update

public void update()

Calculate the current transmission speed from the information given by the interfaces, and calculate the missing data amount.

abortTransfer

public void abortTransfer()

Aborts the transfer of the currently transferred message.

getRemainingByteCount

public abstract int getRemainingByteCount()

Returns the amount of bytes to be transferred before ongoing transfer is ready or 0 if there's no ongoing transfer or it has finished already

Returns:

the amount of bytes to be transferred

clearMsgOnFly

protected void clearMsgOnFly()

Clears the message that is currently being transferred. Calls to getMessage() will return null after this.

finalizeTransfer

public void finalizeTransfer()

Finalizes the transfer of the currently transferred message. The message that was being transferred can not be retrieved from this connections after calling this method (using getMessage()).

isMessageTransferred

public abstract boolean isMessageTransferred()

Returns true if the current message transfer is done

Returns:

True if the transfer is done, false if not

isReadyForTransfer

public boolean isReadyForTransfer()

Returns true if the connection is ready to transfer a message (connection is up and there is no message being transferred).

Returns:

true if the connection is ready to transfer a message

getMessage

public Message getMessage()

Gets the message that this connection is currently transferring.

Returns:

The message or null if no message is being transferred

getSpeed

public abstract double getSpeed()

Gets the current connection speed

getTotalBytesTransferred

public int getTotalBytesTransferred()

Returns the total amount of bytes this connection has transferred so far (including all transfers).

getOtherNode

public DTNHost getOtherNode(DTNHost node)

Returns the node in the other end of the connection

Parameters:

node - The node in this end of the connection

Returns:

The requested node

getOtherInterface

public NetworkInterface getOtherInterface(NetworkInterface i)

Returns the interface in the other end of the connection

Parameters:

i - The interface in this end of the connection

Returns:

The requested interface

toString

public java.lang.String toString()

Returns a String presentation of the connection.

Overrides:

toString in class java.lang.Object