ch.epfl.lsr.apex.services
Class APEXReliableBroadcastService

java.lang.Object
  ch.epfl.lsr.apex.services.APEXService
      ch.epfl.lsr.apex.services.APEXReliableBroadcastService

public class APEXReliableBroadcastService

extends APEXService

The 'Reliable Broadcast Service' is an additional service for the APEX model. It is registered with the external URI 'http://lsrwww.epfl.ch/APEX/reliableBroadcast' and internal SERVICENAME 'APEXReliableBroadcast'.

A message containing an option with the form:

<option external='http://lsrwww.epfl.ch/APEX/reliableBroadcast' targetHop='final'
mustUnderstand='true' transID='2'>
<endpoint identity='user1@lsrwww.epfl.ch' order='0' />
<endpoint identity='user2@ltiwww.epfl.ch' order='1' />
<endpoint identity='user3@lcawww.epfl.ch' order='2' />
</option>

invokes the use of this service.

The reliable service is only used in relays which go along the order of every specified endpoint and sends a message, dependant on if the order of the endpoint is less than the order of all its attached and specified endpoints and on if it hasn't already sent a message to the corresponding endpoint.

Author:

Marc Stoecklin

See Also:

APEXService

Field Summary

static String	ORDER Reliable Broadcast service syntax: order
static String	RELIABLEBROADCAST External URI for a reliable broadcast option: http://lsrwww.epfl.ch/APEX/reliableBroadcast
static String	SERVICENAME Service name: APEXReliableBroadcast

Fields inherited from class ch.epfl.lsr.apex.services.APEXService

manager

Constructor Summary

APEXReliableBroadcastService()
Creates a new APEXReliableBroadcastService within the specified APEX manager

Method Summary

Hashtable	getOptions() Returns a table of all options this service is willing to handle.
static APEXOption	getReliableBroadcastOption(APEXEndpointManager manager, APEXEndpointAddress originator, APEXEndpointAddress[] destinations) Returns an 'APEXOption' formed for 'Reliable Broadcast'.
void	handleDiscarded(APEXOption option, APEXMessage message, int code, String reason, String hopName) This method is not used for reliable broadcast service
void	handleMessage(APEXMessage message) Handles an incoming message destined explicitly to this service.
void	handleOption(APEXOption option, APEXMessage message, String administrativeDomain) Handles an option destinated to this service.
void	handleReliableBroadcastOption(APEXOption option, APEXDataMessage message, String administrativeDomain) Handles a 'reliable broadcast' option and sends appropriate messages to the relay.
void	handleSent(APEXOption option, APEXMessage message, APEXReply reply, String hopName) This method is not used for reliable broadcast service

Methods inherited from class ch.epfl.lsr.apex.services.APEXService

setManager

Methods inherited from class java.lang.Object

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

Field Detail

SERVICENAME

public static final String SERVICENAME

Service name: APEXReliableBroadcast

See Also:

Constant Field Values

RELIABLEBROADCAST

public static final String RELIABLEBROADCAST

External URI for a reliable broadcast option: http://lsrwww.epfl.ch/APEX/reliableBroadcast

See Also:

Constant Field Values

ORDER

public static final String ORDER

Reliable Broadcast service syntax: order

See Also:

Constant Field Values

Constructor Detail

APEXReliableBroadcastService

public APEXReliableBroadcastService()

Creates a new APEXReliableBroadcastService within the specified APEX manager

Method Detail

handleMessage

public void handleMessage(APEXMessage message)

Handles an incoming message destined explicitly to this service.

Specified by:

handleMessage in class APEXService

Parameters:

message - The incoming message to handle

handleOption

public void handleOption(APEXOption option,
                         APEXMessage message,
                         String administrativeDomain)
                  throws APEXOptionException

Handles an option destinated to this service. This method is invoked only if the option targetHop field is set to final and at least one endpoint is applicable.

Specified by:

handleOption in class APEXService

Parameters:

option - The option to handle

message - The message which contains the option

administrativeDomain - The administrative domain of the processing relay

Throws:

APEXOptionException - Thrown on an error in processing the option

See Also:

APEXOption

getOptions

public Hashtable getOptions()

Returns a table of all options this service is willing to handle.

Specified by:

getOptions in class APEXService

Returns:

Hashtable containing option identifiers this services handles as well as their corresponding handlers.

handleReliableBroadcastOption

public void handleReliableBroadcastOption(APEXOption option,
                                          APEXDataMessage message,
                                          String administrativeDomain)
                                   throws APEXOptionException

Handles a 'reliable broadcast' option and sends appropriate messages to the relay.

Parameters:

option - The option to handle

message - The message which contains the option

administrativeDomain - The administrative domain of the processing relay

Throws:

APEXOptionException - Thrown if there is an error in processing the option

getReliableBroadcastOption

public static APEXOption getReliableBroadcastOption(APEXEndpointManager manager,
                                                    APEXEndpointAddress originator,
                                                    APEXEndpointAddress[] destinations)
                                             throws APEXOptionException

Returns an 'APEXOption' formed for 'Reliable Broadcast'. The order of the endpoints depends on the order in the address in the array, say key '0' in the array is order '0' (first) in the reliable broadcast algorithm.

Note: a reliable broadcast option is always final and mustUnderstand='true' to guarantee the mechanism

Parameters:

manager - The endpoint manager for the APEX communication

originator - The originator of the message containing the option

destinations - An array of destinated endpoints (ordered!)

Returns:

A correct formed 'Reliable Broadcast Option'

Throws:

APEXOptionException

handleSent

public void handleSent(APEXOption option,
                       APEXMessage message,
                       APEXReply reply,
                       String hopName)

This method is not used for reliable broadcast service

Specified by:

handleSent in class APEXService

Parameters:

option - The option to handle

message - The message successfully sent (modified message)

reply - The reply received by the next hop

hopName - The name of the hop (endpoint address or administrative domain)

handleDiscarded

public void handleDiscarded(APEXOption option,
                            APEXMessage message,
                            int code,
                            String reason,
                            String hopName)

This method is not used for reliable broadcast service

Specified by:

handleDiscarded in class APEXService

Parameters:

option - The option to handle

message - The message successfully sent (modified message)

hopName - The name of the hop (endpoint address or administrative domain)