yass.packet
Class Packet

java.lang.Object
  yass.packet.Packet

Direct Known Subclasses:

IgfPacket

public class Packet
extends java.lang.Object

Represents a data packet which traverses the simulated network

Field Summary

protected double	creationTimestamp The time at which this packet was created
protected double	deadline The time by which this packet must arrive at its destination to be useful
protected Node	destination Eventual destination node of this packet
protected int	headerSize Size of this packet's header, in bits
protected int	id Globally-unique ID for this packet
protected java.lang.Object	payload Packet payload
protected int	payloadSize Size of this packet's payload, in bits
protected java.util.Set<Node>	proposedNextHops The intended next-hop nodes for the next transmission of this packet
protected Route	route Route traversed thus far by this packet
protected int	size Total size of this packet, in bits
protected Node	source Source node of this packet
protected int	ttl Remaining packet TTL in network hops
protected PacketType	type The type of data encapsulated by this packet

Constructor Summary

protected	Packet() No-args constructor to implement initialisation common to all Packet instances.
	Packet(int id, Node source, Node destination, int headerSize, int payloadSize, java.lang.Object payload, java.util.Set<Node> proposedNextHops, double deadline, double creationTimestamp, int ttl, PacketType type) Constructs a new instance of Packet.

Method Summary

void	appendToTrace(Node node) Appends an additional node to the existing node-traversal trace
Packet	copy() Copies this packet, supplying an object representing a distinct instance of the same packet.
int	decrementTtl() Reduces the TTL by 1, and return the new TTL
boolean	equals(java.lang.Object o) Determines if the supplied arbitrary object is equal to this Packet
double	getCreationTimestamp() Obtains the simulation-global time at which the packet was created
double	getDeadline() Obtains the packet delivery deadline
Node	getDestination() Obtains the destination node for this packet
int	getHeaderSize() Obtains the header size, in bits
int	getId() Obtains the globally-unique identifier for this packet
java.lang.Object	getPayload() Obtains the payload attached to this packet
int	getPayloadSize() Obtains the payload size, in bits
java.util.Set<Node>	getProposedNextHops() Obtains the set of proposed next-hop nodes for the next transmission of this packet
Route	getRoute() Obtains the route traversed thus far by this packet
int	getSize() Obtains the total size of this packet, in bits
Node	getSource() Obtains the source node for this packet
int	getTtl() Obtains the remaining TTL in network hops
PacketType	getType() Obtains the type of this packet
int	hashCode() Obtains a hashcode value for this Packet
void	setDestination(Node destination) Sets the packet destination to the supplied node
java.lang.String	toString() Obtains a textual representation of this packet

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

id

protected int id

Globally-unique ID for this packet

size

protected int size

Total size of this packet, in bits

headerSize

protected int headerSize

Size of this packet's header, in bits

payloadSize

protected int payloadSize

Size of this packet's payload, in bits

source

protected Node source

Source node of this packet

destination

protected Node destination

Eventual destination node of this packet

route

protected Route route

Route traversed thus far by this packet

payload

protected java.lang.Object payload

Packet payload

proposedNextHops

protected java.util.Set<Node> proposedNextHops

The intended next-hop nodes for the next transmission of this packet

deadline

protected double deadline

The time by which this packet must arrive at its destination to be useful

creationTimestamp

protected double creationTimestamp

The time at which this packet was created

ttl

protected int ttl

Remaining packet TTL in network hops

type

protected PacketType type

The type of data encapsulated by this packet

Constructor Detail

Packet

protected Packet()

No-args constructor to implement initialisation common to all Packet instances. This constructor should be chained by all public constructors, both of base type Packet and all of its subclasses. This constructor should not be called directly by clients, however, as it only performs partial initialisation; the new Packet instance will not be fully initialised into a consistent state by this constructor alone.

Packet

public Packet(int id,
              Node source,
              Node destination,
              int headerSize,
              int payloadSize,
              java.lang.Object payload,
              java.util.Set<Node> proposedNextHops,
              double deadline,
              double creationTimestamp,
              int ttl,
              PacketType type)

Constructs a new instance of Packet. Subclasses are responsible for overriding this operation if necessary and returning an object of appropriate type, but this return type will always implement the interface of Packet.

Parameters:

ttl - the number of remaining permitted node-node hops for

id - globally-unique ID for this packet

source - source node of this packet

destination - eventual destination node of this packet

payload - packet payload

proposedNextHops - intended next-hop nodes for the next transmission of this packet

deadline - the time by which this packet must arrive at its destination to be considered useful

creationTimestamp - the simulation-global time at which the packet was created, not the node-local time at which the node thinks it created the packet

headerSize - header size, in bits

payloadSize - payload size, in bits

type - the packet type

Method Detail

copy

public Packet copy()

Copies this packet, supplying an object representing a distinct instance of the same packet. This models the situation where a packet is copied from one node to another; the packet posessed by the source and destination are in some sense the same packet, but are nevertheless distinct.

Returns:

a copy of the packet

appendToTrace

public void appendToTrace(Node node)

Appends an additional node to the existing node-traversal trace

Parameters:

node - the node to append to the existing trace

decrementTtl

public int decrementTtl()

Reduces the TTL by 1, and return the new TTL

Returns:

the new TTL

hashCode

public int hashCode()

Obtains a hashcode value for this Packet

Overrides:

hashCode in class java.lang.Object

Returns:

a hashcode value for this Packet

equals

public boolean equals(java.lang.Object o)

Determines if the supplied arbitrary object is equal to this Packet

Overrides:

equals in class java.lang.Object

Parameters:

o - the object against which a test of equality is to be applied

Returns:

true if the supplied object is equal to this Route, otherwise false

toString

public java.lang.String toString()

Obtains a textual representation of this packet

Overrides:

toString in class java.lang.Object

Returns:

a textual representation of this packet

getId

public int getId()

Obtains the globally-unique identifier for this packet

Returns:

the globally-unique identifier for this packet

getSize

public int getSize()

Obtains the total size of this packet, in bits

Returns:

the total size of this packet, in bits

getHeaderSize

public int getHeaderSize()

Obtains the header size, in bits

Returns:

the header size, in bits

getPayloadSize

public int getPayloadSize()

Obtains the payload size, in bits

Returns:

the payload size, in bits

getSource

public Node getSource()

Obtains the source node for this packet

Returns:

the source node for this packet

getDestination

public Node getDestination()

Obtains the destination node for this packet

Returns:

the destination node for this packet

setDestination

public void setDestination(Node destination)

Sets the packet destination to the supplied node

Parameters:

destination - the new destination

getRoute

public Route getRoute()

Obtains the route traversed thus far by this packet

Returns:

the route traversed thus far by this packet

getProposedNextHops

public java.util.Set<Node> getProposedNextHops()

Obtains the set of proposed next-hop nodes for the next transmission of this packet

Returns:

the set of proposed next-hop nodes

getPayload

public java.lang.Object getPayload()

Obtains the payload attached to this packet

Returns:

the payload attached to this packet

getDeadline

public double getDeadline()

Obtains the packet delivery deadline

Returns:

the packet delivery deadline

getCreationTimestamp

public double getCreationTimestamp()

Obtains the simulation-global time at which the packet was created

Returns:

the simulation-global time at which the packet was created

getTtl

public int getTtl()

Obtains the remaining TTL in network hops

Returns:

the remaining TTL in network hops

getType

public PacketType getType()

Obtains the type of this packet

Returns:

the type of this packet