ist.palcom.pubsub
Class PubSubManager

java.lang.Object
  extended by ist.palcom.pubsub.PubSubManager
All Implemented Interfaces:
IHgraphNode

public class PubSubManager
extends java.lang.Object
implements IHgraphNode

A class that manages topic-based publish/subscribe communication.


Field Summary
protected  HgraphNode _node
           
protected  CommunicationManager communicationManager
          The CommunicationManager used for network communication
protected  PalcomScheduler scheduler
           
protected  boolean started
          True while started.
 
Fields inherited from interface ist.palcom.hgraph.IHgraphNode
CHILD_NAME_CLASH, CIRCULARITY_CLASH, COMMAND_OR_NODE_MISSING, ERROR, HANDLER_MISSING, INVOKATOR_MISSING, LISTENER_MISSING, NODE_NOT_CHILD, PATH_MISSING, SIBLING_ALREADY_EXISTS, SIBLING_NONEXISTENT, SIBLING_REFERENCE_ALREADY_EXISTS, SIBLING_REFERENCE_NONEXISTENT, STATUS_OK, VALUE_ALREADY_EXISTS, VALUE_NOT_PRESENT
 
Constructor Summary
PubSubManager(PalcomScheduler scheduler, CommunicationManager communicationManager)
           
 
Method Summary
 int addNodeChild(IHgraphNode node, Path callerPath)
          Adds a child to the node's private list of children.
 java.util.Iterator getChildIterator()
           
 FuncFunc getFuncFunc()
           
 java.lang.String getNodeName()
          hgraph impl below
 IHgraphNode getNodeParent()
           
 Path getPath()
           
 SiblingFunc getSiblingFunc()
           
 ValueFunc getValueFunc()
           
 boolean hasChildNamed(java.lang.String name)
          Checks whether the node has a child with a given name
 boolean isAncestorOf(IHgraphNode node)
          Checks whether this node is an ancestor of the parameter node.
 void publish(java.lang.String topic, Message message)
          Publish a message on a topic.
 int removeNodeChild(java.lang.String name, Path callerPath)
          Removes a child based on its name.
 int setNodeName(java.lang.String name, Path callerPath)
          Sets the name of the node.
 int setNodeParent(IHgraphNode newParent, Path callerPath)
          Sets the parent of the HgraphNode.
 void stop()
          Stops the PubSubManager.
 void subscribe(java.lang.String topic, PalcomThread subscriber)
          Subscribe to a topic.
 java.lang.String toXML()
           
 java.lang.String toXMLFull()
           
 java.lang.String toXMLFullRecursively()
           
 java.lang.String toXMLRecursively()
           
 void unsubscribe(java.lang.String topic, PalcomThread subscriber)
          Stop subscribing to a topic.
 void updatePath()
          Updates the path of the H-Graph node along with its offspring recursively.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

scheduler

protected final PalcomScheduler scheduler

_node

protected HgraphNode _node

communicationManager

protected final CommunicationManager communicationManager
The CommunicationManager used for network communication


started

protected boolean started
True while started.

Constructor Detail

PubSubManager

public PubSubManager(PalcomScheduler scheduler,
                     CommunicationManager communicationManager)
Method Detail

stop

public void stop()
Stops the PubSubManager. Has no effect if it is not started.


subscribe

public void subscribe(java.lang.String topic,
                      PalcomThread subscriber)
Subscribe to a topic. Registers a PalcomThread that will receive messages in MessageEvents.


unsubscribe

public void unsubscribe(java.lang.String topic,
                        PalcomThread subscriber)
Stop subscribing to a topic. The subscriber will be removed from the list of registered subscribers for that topic.


publish

public void publish(java.lang.String topic,
                    Message message)
Publish a message on a topic.


getNodeName

public java.lang.String getNodeName()
hgraph impl below

Specified by:
getNodeName in interface IHgraphNode
Returns:
The name of the node.

setNodeName

public int setNodeName(java.lang.String name,
                       Path callerPath)
Description copied from interface: IHgraphNode
Sets the name of the node. If a sibling already has the name, an error control message is returned

Specified by:
setNodeName in interface IHgraphNode
Parameters:
name - The new name
Returns:
IHgraphNode.STATUS_OK if the change succeeded. IHgraphNode.CHILD_NAME_CLASH if a sibling with the given name already exists.

getPath

public Path getPath()
Specified by:
getPath in interface IHgraphNode
Returns:
the Path object pertaining to the path of the node

updatePath

public void updatePath()
Description copied from interface: IHgraphNode
Updates the path of the H-Graph node along with its offspring recursively. The path is updated when the node name and the node parent is sat.

Specified by:
updatePath in interface IHgraphNode

hasChildNamed

public boolean hasChildNamed(java.lang.String name)
Description copied from interface: IHgraphNode
Checks whether the node has a child with a given name

Specified by:
hasChildNamed in interface IHgraphNode
Parameters:
name - The name to check
Returns:
True iff the node has an actual child with the given name. False if not.

isAncestorOf

public boolean isAncestorOf(IHgraphNode node)
Description copied from interface: IHgraphNode
Checks whether this node is an ancestor of the parameter node. It does so with a depth-first sharch of its offspring (children etc.)

Specified by:
isAncestorOf in interface IHgraphNode
Returns:
true if this node is an ancestor of the parameter node. false if not.

removeNodeChild

public int removeNodeChild(java.lang.String name,
                           Path callerPath)
Description copied from interface: IHgraphNode
Removes a child based on its name.

Specified by:
removeNodeChild in interface IHgraphNode
Parameters:
name - The name of the child to be removed
Returns:
IHgraphNode.STATUS_OK if the operation succeeds

toXML

public java.lang.String toXML()
Specified by:
toXML in interface IHgraphNode
Returns:
A simple xml'ified String of the node (type, name, path, children)

toXMLFull

public java.lang.String toXMLFull()
Specified by:
toXMLFull in interface IHgraphNode
Returns:
A complete xml'ified String of the node (same as simple + handlers, invokators, listeners, values)

toXMLRecursively

public java.lang.String toXMLRecursively()
Specified by:
toXMLRecursively in interface IHgraphNode
Returns:
A simple recursive xml'ified String of the node (type, name, path, children)

toXMLFullRecursively

public java.lang.String toXMLFullRecursively()
Specified by:
toXMLFullRecursively in interface IHgraphNode
Returns:
A complete recursive xml'ified String of the node (same as simple + handlers, invokators, listeners, values) HEAVY!!!

setNodeParent

public int setNodeParent(IHgraphNode newParent,
                         Path callerPath)
Description copied from interface: IHgraphNode
Sets the parent of the HgraphNode. This triggers a recalculation of the path of the node and its offspring

Specified by:
setNodeParent in interface IHgraphNode
Parameters:
newParent - the new parent
Returns:
IHgraphNode.STATUS_OK if the operation succeeds. IHgraphNode.CIRCULARITY_CLASH if the operation causes a circularity.

addNodeChild

public int addNodeChild(IHgraphNode node,
                        Path callerPath)
Description copied from interface: IHgraphNode
Adds a child to the node's private list of children. Ensures that names amongst children are unique

Specified by:
addNodeChild in interface IHgraphNode
Parameters:
node - The new child to be added
Returns:
IHgraphNode.STATUS_OK if the change succeeded. IHgraphNode.CHILD_NAME_CLASH if a sibling with the given name already exists.

getSiblingFunc

public SiblingFunc getSiblingFunc()
Specified by:
getSiblingFunc in interface IHgraphNode
Returns:
The SiblingFunc Sibling functionality object for the given node.

getValueFunc

public ValueFunc getValueFunc()
Specified by:
getValueFunc in interface IHgraphNode
Returns:
The ValueFunc Value functionality object for the given node.

getFuncFunc

public FuncFunc getFuncFunc()
Specified by:
getFuncFunc in interface IHgraphNode
Returns:
The FuncFunc functional functionality (ie. handlers, invokators and listeners) object for the given node.

getNodeParent

public IHgraphNode getNodeParent()
Specified by:
getNodeParent in interface IHgraphNode
Returns:
The parent of the node. null if the parent is root

getChildIterator

public java.util.Iterator getChildIterator()
Specified by:
getChildIterator in interface IHgraphNode
Returns:
An Iterator over the children of the node