biz.hammurapi.rules
Class QueueingRulesContainer

java.lang.Object
  biz.hammurapi.util.VisitableBase
      biz.hammurapi.config.GenericContainer
          biz.hammurapi.config.DomConfigurableContainer
              biz.hammurapi.rules.RulesContainerBase
                  biz.hammurapi.rules.QueueingRulesContainer

All Implemented Interfaces:

biz.hammurapi.config.Command, biz.hammurapi.config.Component, biz.hammurapi.config.Context, biz.hammurapi.config.DomConfigurable, biz.hammurapi.metrics.MeasurementCollector, biz.hammurapi.metrics.MeasurementConsumer, Constants, KnowledgeBase, biz.hammurapi.util.Attributable, biz.hammurapi.util.Searchable, biz.hammurapi.util.Visitable

public class QueueingRulesContainer
extends RulesContainerBase
implements Constants

This rules container uses QueuingDispatcher and negation semantics for remove(). It can also leverage worker (thread pool) provided in worker-ref attribute for multithreaded inference. This container also uses loop detection.

Author:

Pavel Vlasov

Nested Class Summary

Nested classes/interfaces inherited from interface biz.hammurapi.rules.KnowledgeBase

KnowledgeBase.KnowledgeBaseCommand

Field Summary

Fields inherited from interface biz.hammurapi.rules.Constants

COLLECTION_MANAGER, DESCRIPTION, HANDLE_MANAGER, KNOWLEDGE_COMPACTOR, NAME, NEGATOR_CLASS, OBJECT_FILTER, RETAIN_NEGATORS, RULES, URI_DIRECT, URI_PROPERTY, WORKER_REF

Constructor Summary

QueueingRulesContainer()

Method Summary

void	add(java.lang.Object obj) Adds object to handle manager and dispatches to rules.
protected boolean	checkLoop(java.lang.Object object) Checks recent conclusions and derivation depth to discard conclusions which came through dispatching too many times or conclusions with too big depth.
void	configure(org.w3c.dom.Node configNode, biz.hammurapi.config.Context context, java.lang.ClassLoader classLoader)
void	executeRules() Invokes dispatcher's join() to wait until all jobs are finished.
protected java.util.Collection	getObjectActions(java.lang.Object obj) Returns actions performed when object was added to the database.
java.util.Collection	getRules()
protected Negator	newNegator(java.lang.Object obj) Instantiates new negator.
protected void	onDiscardedConclusion(Conclusion conclusion) Conclusions discarded because their derivation depth is too big are passed to this method.
protected void	onDispatchException(DispatchException exception) Consumes DispatchException.
void	remove(java.lang.Object obj) Removes object from handle manager and recent facts.
void	reset() Resets rules state (if any).
void	start()
void	stop()

Methods inherited from class biz.hammurapi.rules.RulesContainerBase

getComponentName

Methods inherited from class biz.hammurapi.config.GenericContainer

acceptChildren, addComponent, addMeasurement, execute, get, getAttribute, getComponentMap, getComponentNames, getComponents, getMeasurementConsumer, getOwner, removeAttribute, setAttribute, setMeasurementConsumer, setOwner

Methods inherited from class biz.hammurapi.util.VisitableBase

accept, convert2searchable, find, findAll, object2visitor

Methods inherited from class java.lang.Object

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

Constructor Detail

QueueingRulesContainer

public QueueingRulesContainer()

Method Detail

add

public void add(java.lang.Object obj)

Adds object to handle manager and dispatches to rules. If the object is instance of Negator then it is presented to collection manager.

Specified by:

add in interface KnowledgeBase

onDispatchException

protected void onDispatchException(DispatchException exception)

Consumes DispatchException. This implementation just prints stack trace. Override if needed.

Parameters:

exception -

checkLoop

protected boolean checkLoop(java.lang.Object object)

Checks recent conclusions and derivation depth to discard conclusions which came through dispatching too many times or conclusions with too big depth.

Parameters:

object -

Returns:

true if there is no loop

onDiscardedConclusion

protected void onDiscardedConclusion(Conclusion conclusion)

Conclusions discarded because their derivation depth is too big are passed to this method. The method does nothing. Override as needed.

Parameters:

conclusion -

remove

public void remove(java.lang.Object obj)

Removes object from handle manager and recent facts. Then creates a negator, negates facts in collection manager and then dispatches the object to remove methods. Subclasses implementing ActionTracing undo actions instead of using a negator.

Specified by:

remove in interface KnowledgeBase

getObjectActions

protected java.util.Collection getObjectActions(java.lang.Object obj)

Returns actions performed when object was added to the database. This method must be overriden by subclasses which implement ActionTracer.

Parameters:

obj -

Returns:

newNegator

protected Negator newNegator(java.lang.Object obj)

Instantiates new negator.

Parameters:

obj -

Returns:

executeRules

public void executeRules()

Invokes dispatcher's join() to wait until all jobs are finished.

Specified by:

executeRules in interface KnowledgeBase

configure

public void configure(org.w3c.dom.Node configNode,
                      biz.hammurapi.config.Context context,
                      java.lang.ClassLoader classLoader)
               throws biz.hammurapi.config.ConfigurationException

Specified by:

configure in interface biz.hammurapi.config.DomConfigurable

Overrides:

configure in class biz.hammurapi.config.DomConfigurableContainer

Throws:

biz.hammurapi.config.ConfigurationException

start

public void start()
           throws biz.hammurapi.config.ConfigurationException

Specified by:

start in interface biz.hammurapi.config.Component

Overrides:

start in class biz.hammurapi.config.GenericContainer

Throws:

biz.hammurapi.config.ConfigurationException

stop

public void stop()
          throws biz.hammurapi.config.ConfigurationException

Specified by:

stop in interface biz.hammurapi.config.Component

Overrides:

stop in class biz.hammurapi.config.GenericContainer

Throws:

biz.hammurapi.config.ConfigurationException

reset

public void reset()

Description copied from interface: KnowledgeBase

Resets rules state (if any).

Specified by:

reset in interface KnowledgeBase

getRules

public java.util.Collection getRules()

Specified by:

getRules in interface KnowledgeBase

Returns:

Collection of rule instances in the knowledge base.