ptolemy.actor.ptalon.lib
Class MapWorker

java.lang.Object
  ptolemy.kernel.util.NamedObj
      ptolemy.kernel.InstantiableNamedObj
          ptolemy.kernel.Entity
              ptolemy.kernel.ComponentEntity
                  ptolemy.actor.AtomicActor
                      ptolemy.actor.TypedAtomicActor
                          ptolemy.actor.ptalon.lib.MapWorker

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable

public class MapWorker
extends TypedAtomicActor

A MapWorker actor, as a subsystem of the MapReduce system.

This actor has a parameter classNameForMap which is the qualified name for a Java class that extends ptolemy.actor.ptalon.lib.MapReduceAlgorithm. It must also have a no argument constructor. By extending this abstract class, it will implement a method named map with type signature:

public List<KeyValuePair> map(String key, String value)

This method defines the Map algorithm for the MapReduce system. At each call, it should return list of KeyValuePairs, which is just a pair of strings, one representing a key for the reduce algorithm, and one representing a value for the reduce algorithm. One instance of the MapReduce algorithm class will be created when the classNameForMap parameter is set. It will be reused at each firing. This actor inputs a key and value token and outputs key, value pairs for each pair in the list generated by the user defined map procedure.

Since:

Ptolemy II 6.1

Version:

$Id: MapWorker.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Adam Cataldo, Adam Cataldo

See Also:

KeyValuePair, MapReduceAlgorithm, Serialized Form

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (cxh)

Nested Class Summary

Nested classes/interfaces inherited from class ptolemy.kernel.Entity

Entity.ContainedObjectsIterator

Field Summary

private MapReduceAlgorithm	_algorithm
StringParameter	classNameForMap The qualifed class name for a Java class containing a method with signature: public static List<String[]> map(String key, String value) Each element of each returned list should be a length two array of Strings.
TypedIOPort	inputKey A String input key.
TypedIOPort	inputValue A String input value.
TypedIOPort	outputKey A String output key.
TypedIOPort	outputValue A String output value.

Fields inherited from class ptolemy.actor.AtomicActor

_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested

Fields inherited from class ptolemy.kernel.util.NamedObj

_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS

Fields inherited from interface ptolemy.actor.Executable

COMPLETED, NOT_READY, STOP_ITERATING

Constructor Summary

MapWorker(CompositeEntity container, java.lang.String name)
Create a new actor in the specified container with the specified name.

Method Summary

private void	_setMapMethod() Set the map method using the class specified in classNameForMap.
void	attributeChanged(Attribute attribute) React to a change in an attribute.
void	fire() Read in a token on the inputKey and inputValue ports and output pairs of tokens on the ouputKey, outputValue ports.
void	initialize() Extract the map method from the classNameForMap parameter.
boolean	prefire() Return true if there is an available key token and value token on the inputKey and inputValue ports.

Methods inherited from class ptolemy.actor.TypedAtomicActor

_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints

Methods inherited from class ptolemy.actor.AtomicActor

_actorFiring, _actorFiring, addActorFiringListener, addInitializable, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup

Methods inherited from class ptolemy.kernel.ComponentEntity

_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName

Methods inherited from class ptolemy.kernel.Entity

_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName

Methods inherited from class ptolemy.kernel.InstantiableNamedObj

_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition

Methods inherited from class ptolemy.kernel.util.NamedObj

_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.actor.Actor

createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList

Methods inherited from interface ptolemy.actor.Executable

isFireFunctional, isStrict, iterate, postfire, stop, stopFire, terminate

Methods inherited from interface ptolemy.actor.Initializable

addInitializable, preinitialize, removeInitializable, wrapup

Methods inherited from interface ptolemy.kernel.util.Nameable

description, getContainer, getDisplayName, getFullName, getName, getName, setName

Methods inherited from interface ptolemy.kernel.util.Derivable

getDerivedLevel, getDerivedList, propagateValue

Field Detail

classNameForMap

public StringParameter classNameForMap

The qualifed class name for a Java class containing a method with signature:

public static List<String[]> map(String key, String value)

Each element of each returned list should be a length two array of Strings.

inputKey

public TypedIOPort inputKey

A String input key.

inputValue

public TypedIOPort inputValue

A String input value.

outputKey

public TypedIOPort outputKey

A String output key. For each pair of inputKey, inputValue tokens read in, a possibly empty list of outputKey, outputValue pairs will be outputs.

outputValue

public TypedIOPort outputValue

A String output value. For each pair of inputKey, inputValue tokens read in, a possibly empty list of outputKey, outputValue pairs will be outputs.

_algorithm

private MapReduceAlgorithm _algorithm

Constructor Detail

MapWorker

public MapWorker(CompositeEntity container,
                 java.lang.String name)
          throws IllegalActionException,
                 NameDuplicationException

Create a new actor in the specified container with the specified name. The name must be unique within the container or an exception is thrown. The container argument must not be null, or a NullPointerException will be thrown.

Parameters:

container - The container.

name - The name of this actor within the container.

Throws:

IllegalActionException - If this actor cannot be contained by the proposed container (see the setContainer() method).

NameDuplicationException - If the name coincides with an entity already in the container.

Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException

React to a change in an attribute. This method is called by a contained attribute when its value changes. In this base class, the method does nothing. In derived classes, this method may throw an exception, indicating that the new attribute value is invalid. It is up to the caller to restore the attribute to a valid value if an exception is thrown. If the attribute changed is classNameForMap, update this actor accordingly.

Overrides:

attributeChanged in class NamedObj

Parameters:

attribute - The attribute that changed.

Throws:

IllegalActionException - If the change is not acceptable to this container. If the class set in classNameForMap does not exist, or if the class exists but does not contain a map method with an appropriate signature, this exception will be thrown.

fire

public void fire()
          throws IllegalActionException

Read in a token on the inputKey and inputValue ports and output pairs of tokens on the ouputKey, outputValue ports.

Specified by:

fire in interface Executable

Overrides:

fire in class AtomicActor

Throws:

IllegalActionException - If there is any trouble calling the map method.

prefire

public boolean prefire()
                throws IllegalActionException

Return true if there is an available key token and value token on the inputKey and inputValue ports.

Specified by:

prefire in interface Executable

Overrides:

prefire in class AtomicActor

Returns:

True if this actor is ready for firing, false otherwise.

Throws:

IllegalActionException - Not thrown in this class.

initialize

public void initialize()
                throws IllegalActionException

Extract the map method from the classNameForMap parameter.

Specified by:

initialize in interface Initializable

Overrides:

initialize in class AtomicActor

Throws:

IllegalActionException - If unable to extract an appropriate map method.

_setMapMethod

private void _setMapMethod()
                    throws IllegalActionException

Set the map method using the class specified in classNameForMap.

Throws:

IllegalActionException - If the map method does not exist, has the wrong type signature, or has the wrong access modifiers.