org.drools.reteoo
Class WindowNode

java.lang.Object
  org.drools.common.BaseNode
      org.drools.reteoo.ObjectSource
          org.drools.reteoo.WindowNode

All Implemented Interfaces:

Externalizable, Serializable, NetworkNode, NodeMemory, ObjectSink, ObjectSinkNode, Sink

public class WindowNode
extends ObjectSource
implements ObjectSinkNode, NodeMemory

WindowNodes are nodes in the Rete network used to manage windows. They support multiple types of windows, like sliding windows, tumbling windows, etc. This class must act as a lock-gate for all working memory actions on it and propagated down the network in this branch, as there can be concurrent threads propagating events and expiring events working on this node at the same time. It requires it to be thread safe.

See Also:

Serialized Form

Nested Class Summary

static class

WindowNode.WindowMemory

Field Summary

Fields inherited from class org.drools.reteoo.ObjectSource

declaredMask, inferredMask, sink, source

Fields inherited from class org.drools.common.BaseNode

associations, id, partitionId, partitionsEnabled

Constructor Summary

WindowNode()

WindowNode(int id, List<AlphaNodeFieldConstraint> constraints, List<Behavior> behaviors, ObjectSource objectSource, BuildContext context)
Construct a WindowNode with a unique id using the provided list of AlphaNodeFieldConstraint and the given ObjectSource.

Method Summary

void	assertObject(InternalFactHandle factHandle, PropagationContext context, InternalWorkingMemory workingMemory)
void	attach(BuildContext context) Attaches the node into the network.
void	byPassModifyToBetaNode(InternalFactHandle factHandle, ModifyPreviousTuples modifyPreviousTuples, PropagationContext context, InternalWorkingMemory workingMemory)
long	calculateDeclaredMask(List<String> settableProperties)
Memory	createMemory(RuleBaseConfiguration config) Creates the WindowNode's memory.
boolean	equals(Object object)
Behavior[]	getBehaviors() Returns the list of behaviors for this window node
List<AlphaNodeFieldConstraint>	getConstraints() Returns the FieldConstraints
EntryPoint	getEntryPoint()
ObjectSinkNode	getNextObjectSinkNode() Returns the next node
ObjectSinkNode	getPreviousObjectSinkNode() Returns the previous node
int	hashCode() The hashCode return is simply the unique id of the node.
void	modifyObject(InternalFactHandle factHandle, ModifyPreviousTuples modifyPreviousTuples, PropagationContext context, InternalWorkingMemory workingMemory)
void	readExternal(ObjectInput in)
void	retractObject(InternalFactHandle factHandle, PropagationContext context, InternalWorkingMemory workingMemory) Retract the FactHandle from the WindowNode.
void	setNextObjectSinkNode(ObjectSinkNode next) Sets the next node
void	setPreviousObjectSinkNode(ObjectSinkNode previous) Sets the previous node
String	toString()
void	updateSink(ObjectSink sink, PropagationContext context, InternalWorkingMemory workingMemory)
void	writeExternal(ObjectOutput out)

Methods inherited from class org.drools.reteoo.ObjectSource

addObjectSink, doRemove, getDeclaredMask, getObjectTypeNode, getParentObjectSource, getSinkPropagator, initDeclaredMask, isInUse, networkUpdated, removeObjectSink, resetInferredMask, updateMask

Methods inherited from class org.drools.common.BaseNode

addAssociation, attach, getAssociations, getId, getPartitionId, remove, removeAssociation, setPartitionId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.drools.common.NetworkNode

getId, getPartitionId

Methods inherited from interface org.drools.common.NodeMemory

getId

Constructor Detail

WindowNode

public WindowNode()

WindowNode

public WindowNode(int id,
                  List<AlphaNodeFieldConstraint> constraints,
                  List<Behavior> behaviors,
                  ObjectSource objectSource,
                  BuildContext context)

Construct a WindowNode with a unique id using the provided list of AlphaNodeFieldConstraint and the given ObjectSource.

Parameters:

id - Node's ID

constraints - Node's constraints

behaviors - list of behaviors for this window node

objectSource - Node's object source

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Overrides:

readExternal in class ObjectSource

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Overrides:

writeExternal in class ObjectSource

Throws:

IOException

getConstraints

public List<AlphaNodeFieldConstraint> getConstraints()

Returns the FieldConstraints

Returns:

FieldConstraints

getBehaviors

public Behavior[] getBehaviors()

Returns the list of behaviors for this window node

Returns:

attach

public void attach(BuildContext context)

Description copied from class: BaseNode

Attaches the node into the network. Usually to the parent ObjectSource or TupleSource

Specified by:

attach in class BaseNode

assertObject

public void assertObject(InternalFactHandle factHandle,
                         PropagationContext context,
                         InternalWorkingMemory workingMemory)

Specified by:

assertObject in interface ObjectSink

modifyObject

public void modifyObject(InternalFactHandle factHandle,
                         ModifyPreviousTuples modifyPreviousTuples,
                         PropagationContext context,
                         InternalWorkingMemory workingMemory)

Specified by:

modifyObject in interface ObjectSink

retractObject

public void retractObject(InternalFactHandle factHandle,
                          PropagationContext context,
                          InternalWorkingMemory workingMemory)

Retract the FactHandle from the WindowNode. This method is for the node benefit only as the node itself will not propagate retracts down the network, relying on the standard Rete retract algorithm implemented by the ObjectTypeNode to do it.

Parameters:

factHandle - The fact handle.

context - The propagation context

workingMemory - The working memory session.

byPassModifyToBetaNode

public void byPassModifyToBetaNode(InternalFactHandle factHandle,
                                   ModifyPreviousTuples modifyPreviousTuples,
                                   PropagationContext context,
                                   InternalWorkingMemory workingMemory)

Specified by:

byPassModifyToBetaNode in interface ObjectSink

updateSink

public void updateSink(ObjectSink sink,
                       PropagationContext context,
                       InternalWorkingMemory workingMemory)

Specified by:

updateSink in class ObjectSource

createMemory

public Memory createMemory(RuleBaseConfiguration config)

Creates the WindowNode's memory.

Specified by:

createMemory in interface NodeMemory

toString

public String toString()

Overrides:

toString in class BaseNode

hashCode

public int hashCode()

Description copied from class: BaseNode

The hashCode return is simply the unique id of the node. It is expected that base classes will also implement equals(Object object).

Overrides:

hashCode in class BaseNode

equals

public boolean equals(Object object)

Overrides:

equals in class Object

getNextObjectSinkNode

public ObjectSinkNode getNextObjectSinkNode()

Returns the next node

Specified by:

getNextObjectSinkNode in interface ObjectSinkNode

Returns:

The next ObjectSinkNode

setNextObjectSinkNode

public void setNextObjectSinkNode(ObjectSinkNode next)

Sets the next node

Specified by:

setNextObjectSinkNode in interface ObjectSinkNode

Parameters:

next - The next ObjectSinkNode

getPreviousObjectSinkNode

public ObjectSinkNode getPreviousObjectSinkNode()

Returns the previous node

Specified by:

getPreviousObjectSinkNode in interface ObjectSinkNode

Returns:

The previous ObjectSinkNode

setPreviousObjectSinkNode

public void setPreviousObjectSinkNode(ObjectSinkNode previous)

Sets the previous node

Specified by:

setPreviousObjectSinkNode in interface ObjectSinkNode

Parameters:

previous - The previous ObjectSinkNode

getEntryPoint

public EntryPoint getEntryPoint()

calculateDeclaredMask

public long calculateDeclaredMask(List<String> settableProperties)

Specified by:

calculateDeclaredMask in class ObjectSource