springs.rns
Class RegionNameServer

java.lang.Object
  |
  +--springs.rns.RegionNameServer

Direct Known Subclasses:

RegionNameServer_RMIImpl

public abstract class RegionNameServer

extends java.lang.Object

The Region Name Server (RNS).

Author:

Raquel Trillo Lado

Nested Class Summary

(package private) class

RegionNameServer.ContextWatcher

Field Summary

private java.util.Hashtable	_agentLocationServers
private java.util.Hashtable	_contextInformations A table storing the addresses of contexts in the region and the contexts that track every agent created in the region.
private RegionNameServer.ContextWatcher	_cw The context watcher.
private int	_trackingFactor Number of contexts that should track the location of every agent.

Constructor Summary

RegionNameServer()

Method Summary

java.util.Vector	addAgent(java.lang.String agentName, springs.context.ContextAddress ca)
java.util.Hashtable	addContext(springs.context.ContextAddress ca)
private java.util.Vector	allocateLocationServers() Allocate locationServers to follow an agent.
private void	contextUnavailable(java.lang.String cn) Considers that the given context is not anymore available for tracking agents.
private void	contextUnavailable(java.lang.String cn, java.util.Collection unAvailableContext) Considers that the given context is not anymore available for tracking agents.
private void	contextUnavailableForTracking(java.lang.String cn) Considers that the given context is not anymore available for tracking agents.
private java.lang.String	getNamesRegisteredAgents()
springs.rns.SearchingInformation	getSearchingInformation(java.lang.String agentName, springs.context.ContextAddress ca)
protected void	initialize() Initializes the server.
private void	newContextAvailable(springs.context.ContextAddress ca) Considers that there is a new context available to assign the task of tracking agents.
void	printAgents()
void	printContexts()
void	printLocationServersFor(java.lang.String agentName)
void	removeAgent(java.lang.String agentName, springs.context.ContextAddress ca)
void	removeContext(java.lang.String cn, java.util.Collection ownedAgents)
protected abstract void	start() Starts the Region Name Server.
private void	watchContexts() Watchs if every context in the region is alive.

Methods inherited from class java.lang.Object

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

Field Detail

_contextInformations

private java.util.Hashtable _contextInformations

A table storing the addresses of contexts in the region and the contexts that track every agent created in the region.

_agentLocationServers

private java.util.Hashtable _agentLocationServers

_cw

private transient RegionNameServer.ContextWatcher _cw

The context watcher.

_trackingFactor

private int _trackingFactor

Number of contexts that should track the location of every agent.

Constructor Detail

RegionNameServer

public RegionNameServer()

Method Detail

start

protected abstract void start()
                       throws RNSStartingException

Starts the Region Name Server.

Throws:

RNSStartingException - if error.

See Also:

RNSStartingException

initialize

protected void initialize()

Initializes the server. It must be called from the start() method.

addContext

public java.util.Hashtable addContext(springs.context.ContextAddress ca)
                               throws AlreadyExistingContextException

AlreadyExistingContextException

removeContext

public void removeContext(java.lang.String cn,
                          java.util.Collection ownedAgents)
                   throws PermissionException

PermissionException

getNamesRegisteredAgents

private java.lang.String getNamesRegisteredAgents()

addAgent

public java.util.Vector addAgent(java.lang.String agentName,
                                 springs.context.ContextAddress ca)
                          throws AlreadyExistingAgentException,
                                 PermissionException

AlreadyExistingAgentException

PermissionException

removeAgent

public void removeAgent(java.lang.String agentName,
                        springs.context.ContextAddress ca)
                 throws PermissionException

PermissionException

getSearchingInformation

public springs.rns.SearchingInformation getSearchingInformation(java.lang.String agentName,
                                                                springs.context.ContextAddress ca)
                                                         throws PermissionException,
                                                                AgentNotFoundException

PermissionException

AgentNotFoundException

printLocationServersFor

public void printLocationServersFor(java.lang.String agentName)

printAgents

public void printAgents()

printContexts

public void printContexts()

newContextAvailable

private void newContextAvailable(springs.context.ContextAddress ca)

Considers that there is a new context available to assign the task of tracking agents. The current implementation does nothing.

Parameters:

ca - the address of the context.

See Also:

ContextAddress

allocateLocationServers

private java.util.Vector allocateLocationServers()

Allocate locationServers to follow an agent.

Returns:

the vector of locationServers, with their context's addresses.

See Also:

Vector

contextUnavailable

private void contextUnavailable(java.lang.String cn)

Considers that the given context is not anymore available for tracking agents.

Parameters:

cn - the name of the context to remove. This context is not in Hashtable yet.

See Also:

String

contextUnavailable

private void contextUnavailable(java.lang.String cn,
                                java.util.Collection unAvailableContext)

Considers that the given context is not anymore available for tracking agents.

Parameters:

cn - the name of the context to remove. This context is still in Hashtable.

unAvailableContext - a list of context which can not be pinged.

See Also:

String, String

contextUnavailableForTracking

private void contextUnavailableForTracking(java.lang.String cn)

Considers that the given context is not anymore available for tracking agents.

Parameters:

cn - the name of the context to remove.

See Also:

String

watchContexts

private void watchContexts()

Watchs if every context in the region is alive.