Class Transport

java.lang.Object
  Transport

public class Transport
extends java.lang.Object

   
 This conveys the header for reliable message transfer.
 This is carried in the payload of a Packet, and in turn the data being
 transferred is carried in the payload of the Transport packet.
 

Field Summary

static int	ACK
static int	DATA
static int	FIN
static int	HEADER_SIZE
static int	MAX_PACKET_SIZE
static int	MAX_PAYLOAD_SIZE
static int	MAX_PORT_NUM
static int	SYN

Constructor Summary

Transport(int srcPort, int destPort, int type, int window, int seqNum, byte[] payload)
Constructing a new transport packet.

Method Summary

int	getDestPort()
byte[]	getPayload()
int	getSeqNum()
int	getSrcPort()
int	getType()
int	getWindow()
byte[]	pack() Convert the Transport packet object into a byte array for sending over the wire.
static Transport	unpack(byte[] packet) Unpacks a byte array to create a Transport object Assumes the array has been formatted using pack method in Transport

Methods inherited from class java.lang.Object

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

Field Detail

MAX_PACKET_SIZE

public static final int MAX_PACKET_SIZE

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Constant Field Values

HEADER_SIZE

public static final int HEADER_SIZE

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Constant Field Values

MAX_PAYLOAD_SIZE

public static final int MAX_PAYLOAD_SIZE

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Constant Field Values

MAX_PORT_NUM

public static final int MAX_PORT_NUM

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Constant Field Values

SYN

public static final int SYN

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Constant Field Values

ACK

public static final int ACK

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Constant Field Values

FIN

public static final int FIN

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Constant Field Values

DATA

public static final int DATA

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Constant Field Values

Constructor Detail

Transport

public Transport(int srcPort,
                 int destPort,
                 int type,
                 int window,
                 int seqNum,
                 byte[] payload)
          throws java.lang.IllegalArgumentException

Constructing a new transport packet.

Parameters:

srcPort - The source port

destPort - The destination port

type - The type of packet. Either SYN, ACK, FIN, or DATA

window - The window size

seqNum - The sequence number of the packet

payload - The payload of the packet.

Throws:

java.lang.IllegalArgumentException

Method Detail

getSrcPort

public int getSrcPort()

Returns:

The source port

getDestPort

public int getDestPort()

Returns:

The destination port

getType

public int getType()

Returns:

The type of the packet

getWindow

public int getWindow()

Returns:

The window size

getSeqNum

public int getSeqNum()

Returns:

The sequence number

getPayload

public byte[] getPayload()

Returns:

The payload

pack

public byte[] pack()

Convert the Transport packet object into a byte array for sending over the wire. Format: source port = 1 byte destination port = 1 byte type = 1 byte window size = 4 bytes sequence number = 4 bytes packet length = 1 byte payload <= MAX_PAYLOAD_SIZE bytes

Returns:

A byte[] for transporting over the wire. Null if failed to pack for some reason

unpack

public static Transport unpack(byte[] packet)

Unpacks a byte array to create a Transport object Assumes the array has been formatted using pack method in Transport

Parameters:

packet - String representation of the transport packet

Returns:

Transport object created or null if the byte[] representation was corrupted