Package ai.libs.jaicore.search.algorithms.standard.bestfirst

Class BestFirst<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N,A,V extends java.lang.Comparable<V>>

java.lang.Object

ai.libs.jaicore.basic.algorithm.AAlgorithm<I,O>

ai.libs.jaicore.basic.algorithm.ASolutionCandidateIterator<I,O>

ai.libs.jaicore.basic.algorithm.AOptimizer<I,EvaluatedSearchGraphPath<N,A,V>,V>

ai.libs.jaicore.search.core.interfaces.AOptimalPathInORGraphSearch<I,N,A,V>

ai.libs.jaicore.search.algorithms.standard.bestfirst.BestFirst<I,N,A,V>

Type Parameters:

I -

N -

A -

V -

All Implemented Interfaces:

java.lang.Iterable<org.api4.java.algorithm.events.IAlgorithmEvent>, java.util.concurrent.Callable<EvaluatedSearchGraphPath<N,A,V>>, java.util.Iterator<org.api4.java.algorithm.events.IAlgorithmEvent>, org.api4.java.ai.graphsearch.problem.IOptimalPathInORGraphSearch<I,EvaluatedSearchGraphPath<N,A,V>,N,A,V>, org.api4.java.ai.graphsearch.problem.IPathInORGraphSearch<I,EvaluatedSearchGraphPath<N,A,V>,N,A>, org.api4.java.ai.graphsearch.problem.IPathSearch<I,EvaluatedSearchGraphPath<N,A,V>,N,A>, org.api4.java.algorithm.IAlgorithm<I,EvaluatedSearchGraphPath<N,A,V>>, org.api4.java.algorithm.IOptimizationAlgorithm<I,EvaluatedSearchGraphPath<N,A,V>,V>, org.api4.java.algorithm.ISolutionCandidateIterator<I,EvaluatedSearchGraphPath<N,A,V>>, org.api4.java.common.control.ICancelable, org.api4.java.common.control.ILoggingCustomizable

Direct Known Subclasses:

AStar, StandardBestFirst

public class BestFirst<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N,A,V extends java.lang.Comparable<V>>
extends AOptimalPathInORGraphSearch<I,N,A,V>

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BestFirst.ParentDiscarding

Field Summary

Fields

Modifier and Type	Field	Description
protected java.util.concurrent.atomic.AtomicInteger	activeJobs
protected int	additionalThreadsForNodeAttachment
protected java.util.Map<N,BackPointerPath<N,A,V>>	ext2int
protected org.api4.java.datastructure.graph.implicit.IGraphGenerator<N,A>	graphGenerator
protected org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V>	nodeEvaluator
protected java.util.Queue<BackPointerPath<N,A,V>>	open
protected org.api4.java.ai.graphsearch.problem.implicit.graphgenerator.IPathGoalTester<N,A>	pathGoalTester
protected java.util.Queue<EvaluatedSearchSolutionCandidateFoundEvent<N,A,V>>	pendingSolutionFoundEvents
protected org.api4.java.datastructure.graph.implicit.IRootGenerator<N>	rootGenerator
protected java.util.Queue<EvaluatedSearchGraphPath<N,A,V>>	solutions
protected org.api4.java.datastructure.graph.implicit.ISuccessorGenerator<N,A>	successorGenerator

Constructor Summary

Constructors

Constructor	Description
BestFirst(IBestFirstConfig config, I problem)
BestFirst(IBestFirstConfig config, I problem, org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> lowerBoundEvaluator)
BestFirst(I problem)
BestFirst(I problem, org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> lowerBoundEvaluator)

Method Summary

Modifier and Type	Method	Description
protected void	afterExpansion(BackPointerPath<N,A,V> node)
protected void	afterInitialization()	BLOCK C: Hooks
protected void	afterSelection(BackPointerPath<N,A,V> node)
protected void	beforeExpansion(BackPointerPath<N,A,V> node)
protected boolean	beforeSelection()
void	bootstrap(java.util.Collection<BackPointerPath<N,A,V>> initialNodes)	This method can be used to create an initial graph different from just root nodes.
protected org.api4.java.algorithm.events.IAlgorithmEvent	expandNextNode()	This method conducts the expansion of the next node.
int	getAdditionalThreadsForExpansion()
IBestFirstConfig	getConfig()
int	getCreatedCounter()
java.util.List<N>	getCurrentPathToNode(N node)	BLOCK D: Getters and Setters
int	getExpandedCounter()	Check how many times a node was expanded.
V	getFValue(BackPointerPath<N,A,V> node)
V	getFValue(N node)
BackPointerPath<N,A,V>	getInternalRepresentationOf(N node)
protected BackPointerPath<N,A,V>	getLocalVersionOfNode(BackPointerPath<N,A,V> node)	This is relevant if we work with several copies of a node (usually if we need to copy the search space somewhere).
java.lang.String	getLoggerName()
java.lang.Object	getNodeAnnotation(N node, java.lang.String annotation)
java.util.Map<java.lang.String,java.lang.Object>	getNodeAnnotations(N node)
org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V>	getNodeEvaluator()
java.util.List<BackPointerPath<N,A,V>>	getOpen()
java.util.Queue<EvaluatedSearchGraphPath<N,A,V>>	getSolutionQueue()
int	getTimeoutForComputationOfF()
protected void	initGraph()	This method setups the graph by inserting the root nodes.
protected void	insertNodeIntoLocalGraph(BackPointerPath<N,A,V> node)
protected void	labelNode(BackPointerPath<N,A,V> node)
protected BackPointerPath<N,A,V>	newNode(BackPointerPath<N,A,V> parent, N t2, A arc)
protected BackPointerPath<N,A,V>	newNode(BackPointerPath<N,A,V> parent, N t2, A arc, V evaluation)
NodeExpansionJobSubmittedEvent<N,A,V>	nextNodeExpansion()
EvaluatedSearchGraphPath<N,A,V>	nextSolutionThatDominatesOpen()
org.api4.java.algorithm.events.IAlgorithmEvent	nextWithException()
void	onFValueReceivedEvent(FValueEvent<V> event)
void	receiveNodeAnnotationEvent(NodeAnnotationEvent<N> event)
void	receiveRolloutEvent(RolloutEvent<N,V> event)
void	receiveSolutionCandidateAnnotationEvent(SolutionAnnotationEvent<N,A,V> event)
void	receiveSolutionCandidateEvent(EvaluatedSearchSolutionCandidateFoundEvent<N,A,V> solutionEvent)
protected EvaluatedSearchSolutionCandidateFoundEvent<N,A,V>	registerSolution(EvaluatedSearchGraphPath<N,A,V> solutionPath)
protected void	selectNodeForNextExpansion(BackPointerPath<N,A,V> node)
void	selectNodeForNextExpansion(N node)
void	setLoggerName(java.lang.String name)
void	setOpen(java.util.Queue<BackPointerPath<N,A,V>> collection)
void	setTimeoutForComputationOfF(int timeoutInMS, org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> timeoutEvaluator)
protected void	shutdown()
java.lang.String	toDetailedString()
java.lang.String	toString()

Methods inherited from class ai.libs.jaicore.search.core.interfaces.AOptimalPathInORGraphSearch

getGoalTester, getGraphGenerator, nextSolutionCandidateEvent

Methods inherited from class ai.libs.jaicore.basic.algorithm.AOptimizer

call, getBestScoreKnownToExist, getBestSeenSolution, nextSolutionCandidate, setBestSeenSolution, tellAboutBestScoreKnownToExist, updateBestSeenSolution

Methods inherited from class ai.libs.jaicore.basic.algorithm.ASolutionCandidateIterator

collectAllSolutions

Methods inherited from class ai.libs.jaicore.basic.algorithm.AAlgorithm

activate, announceTimeoutDetected, avoidReinterruptionOnShutdownOnCurrentThread, cancel, checkAndConductTermination, checkTermination, computeTimeoutAware, getActivationTime, getId, getInput, getListeners, getNumCPUs, getRemainingTimeToDeadline, getState, getTimeout, getTimeoutPrecautionOffset, hasNext, hasThreadBeenInterruptedDuringShutdown, interruptThreadAsPartOfShutdown, isCanceled, isShutdownInitialized, isStopCriterionSatisfied, isTimeouted, iterator, next, post, registerActiveThread, registerListener, resolveShutdownInterruptOnCurrentThread, setConfig, setDeadline, setMaxNumThreads, setNumCPUs, setState, setTimeout, setTimeout, setTimeoutPrecautionOffset, terminate, unregisterActiveThread, unregisterThreadAndShutdown

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.api4.java.algorithm.IAlgorithm

call, getId, getInput, getNumCPUs, getTimeout, registerListener, setMaxNumThreads, setNumCPUs, setTimeout, setTimeout

Methods inherited from interface org.api4.java.common.control.ICancelable

cancel

Methods inherited from interface org.api4.java.algorithm.ISolutionCandidateIterator

nextSolutionCandidate

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Field Detail

graphGenerator

protected final org.api4.java.datastructure.graph.implicit.IGraphGenerator<N,A> graphGenerator

rootGenerator

protected final org.api4.java.datastructure.graph.implicit.IRootGenerator<N> rootGenerator

successorGenerator

protected final org.api4.java.datastructure.graph.implicit.ISuccessorGenerator<N,A> successorGenerator

pathGoalTester

protected final org.api4.java.ai.graphsearch.problem.implicit.graphgenerator.IPathGoalTester<N,A> pathGoalTester

nodeEvaluator

protected final org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V extends java.lang.Comparable<V>> nodeEvaluator

solutions

protected final java.util.Queue<EvaluatedSearchGraphPath<N,A,V extends java.lang.Comparable<V>>> solutions

pendingSolutionFoundEvents

protected final java.util.Queue<EvaluatedSearchSolutionCandidateFoundEvent<N,A,V extends java.lang.Comparable<V>>> pendingSolutionFoundEvents

ext2int

protected final java.util.Map<N,BackPointerPath<N,A,V extends java.lang.Comparable<V>>> ext2int

open

protected java.util.Queue<BackPointerPath<N,A,V extends java.lang.Comparable<V>>> open

additionalThreadsForNodeAttachment

protected int additionalThreadsForNodeAttachment

activeJobs

protected final java.util.concurrent.atomic.AtomicInteger activeJobs

Constructor Detail

BestFirst

public BestFirst(I problem)

BestFirst

public BestFirst(I problem,
                 org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> lowerBoundEvaluator)

BestFirst

public BestFirst(IBestFirstConfig config,
                 I problem)

BestFirst

public BestFirst(IBestFirstConfig config,
                 I problem,
                 org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> lowerBoundEvaluator)

Method Detail

newNode

protected BackPointerPath<N,A,V> newNode(BackPointerPath<N,A,V> parent,
                                                     N t2,
                                                     A arc)
                                              throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

newNode

protected BackPointerPath<N,A,V> newNode(BackPointerPath<N,A,V> parent,
                                                     N t2,
                                                     A arc,
                                                     V evaluation)
                                              throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

labelNode

protected void labelNode(BackPointerPath<N,A,V> node)
                  throws org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException,
                         org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException,
                         java.lang.InterruptedException,
                         org.api4.java.algorithm.exceptions.AlgorithmException

Throws:

org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException

org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException

java.lang.InterruptedException

org.api4.java.algorithm.exceptions.AlgorithmException

initGraph

protected void initGraph()
                  throws org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException,
                         org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException,
                         java.lang.InterruptedException,
                         org.api4.java.algorithm.exceptions.AlgorithmException

This method setups the graph by inserting the root nodes.

Throws:

java.lang.InterruptedException

org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException

java.util.concurrent.TimeoutException

org.api4.java.algorithm.exceptions.AlgorithmException

org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException

selectNodeForNextExpansion

protected void selectNodeForNextExpansion(BackPointerPath<N,A,V> node)
                                   throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

expandNextNode

protected org.api4.java.algorithm.events.IAlgorithmEvent expandNextNode()
                                                                 throws java.lang.InterruptedException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmException

This method conducts the expansion of the next node. Unless the next node has been selected from outside, it selects the first node on OPEN (if OPEN is empty but active jobs are running, it waits until those terminate)

Returns:

Throws:

java.lang.InterruptedException

org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException

java.util.concurrent.TimeoutException

org.api4.java.algorithm.exceptions.AlgorithmException

org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException

registerSolution

protected EvaluatedSearchSolutionCandidateFoundEvent<N,A,V> registerSolution(EvaluatedSearchGraphPath<N,A,V> solutionPath)

Overrides:

registerSolution in class AOptimalPathInORGraphSearch<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N,A,V extends java.lang.Comparable<V>>

shutdown

protected void shutdown()

Overrides:

shutdown in class ai.libs.jaicore.basic.algorithm.AAlgorithm<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,EvaluatedSearchGraphPath<N,A,V extends java.lang.Comparable<V>>>

receiveSolutionCandidateEvent

public void receiveSolutionCandidateEvent(EvaluatedSearchSolutionCandidateFoundEvent<N,A,V> solutionEvent)

receiveRolloutEvent

public void receiveRolloutEvent(RolloutEvent<N,V> event)

receiveSolutionCandidateAnnotationEvent

public void receiveSolutionCandidateAnnotationEvent(SolutionAnnotationEvent<N,A,V> event)

receiveNodeAnnotationEvent

public void receiveNodeAnnotationEvent(NodeAnnotationEvent<N> event)

insertNodeIntoLocalGraph

protected void insertNodeIntoLocalGraph(BackPointerPath<N,A,V> node)
                                 throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

getLocalVersionOfNode

protected BackPointerPath<N,A,V> getLocalVersionOfNode(BackPointerPath<N,A,V> node)

This is relevant if we work with several copies of a node (usually if we need to copy the search space somewhere).

Parameters:

node -

Returns:

bootstrap

public void bootstrap(java.util.Collection<BackPointerPath<N,A,V>> initialNodes)
               throws java.lang.InterruptedException

This method can be used to create an initial graph different from just root nodes. This can be interesting if the search is distributed and we want to search only an excerpt of the original one.

Parameters:

initialNodes -

Throws:

java.lang.InterruptedException

nextWithException

public org.api4.java.algorithm.events.IAlgorithmEvent nextWithException()
                                                                 throws java.lang.InterruptedException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException,
                                                                        org.api4.java.algorithm.exceptions.AlgorithmException

Throws:

java.lang.InterruptedException

org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException

org.api4.java.algorithm.exceptions.AlgorithmTimeoutedException

org.api4.java.algorithm.exceptions.AlgorithmException

selectNodeForNextExpansion

public void selectNodeForNextExpansion(N node)
                                throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

nextNodeExpansion

public NodeExpansionJobSubmittedEvent<N,A,V> nextNodeExpansion()

nextSolutionThatDominatesOpen

public EvaluatedSearchGraphPath<N,A,V> nextSolutionThatDominatesOpen()
                                                                          throws java.lang.InterruptedException,
                                                                                 org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException,
                                                                                 java.util.concurrent.TimeoutException,
                                                                                 org.api4.java.algorithm.exceptions.AlgorithmException

Throws:

java.lang.InterruptedException

org.api4.java.algorithm.exceptions.AlgorithmExecutionCanceledException

java.util.concurrent.TimeoutException

org.api4.java.algorithm.exceptions.AlgorithmException

afterInitialization

protected void afterInitialization()

BLOCK C: Hooks

beforeSelection

protected boolean beforeSelection()

afterSelection

protected void afterSelection(BackPointerPath<N,A,V> node)

beforeExpansion

protected void beforeExpansion(BackPointerPath<N,A,V> node)

afterExpansion

protected void afterExpansion(BackPointerPath<N,A,V> node)

getCurrentPathToNode

public java.util.List<N> getCurrentPathToNode(N node)

BLOCK D: Getters and Setters

getNodeEvaluator

public org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> getNodeEvaluator()

getAdditionalThreadsForExpansion

public int getAdditionalThreadsForExpansion()

getTimeoutForComputationOfF

public int getTimeoutForComputationOfF()

setTimeoutForComputationOfF

public void setTimeoutForComputationOfF(int timeoutInMS,
                                        org.api4.java.ai.graphsearch.problem.pathsearch.pathevaluation.IPathEvaluator<N,A,V> timeoutEvaluator)

getOpen

public java.util.List<BackPointerPath<N,A,V>> getOpen()

Returns:

the openCollection

getInternalRepresentationOf

public BackPointerPath<N,A,V> getInternalRepresentationOf(N node)

setOpen

public void setOpen(java.util.Queue<BackPointerPath<N,A,V>> collection)

Parameters:

open - the openCollection to set

getLoggerName

public java.lang.String getLoggerName()

Specified by:

getLoggerName in interface org.api4.java.common.control.ILoggingCustomizable

Overrides:

getLoggerName in class AOptimalPathInORGraphSearch<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N,A,V extends java.lang.Comparable<V>>

setLoggerName

public void setLoggerName(java.lang.String name)

Specified by:

setLoggerName in interface org.api4.java.common.control.ILoggingCustomizable

Overrides:

setLoggerName in class AOptimalPathInORGraphSearch<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N,A,V extends java.lang.Comparable<V>>

getSolutionQueue

public java.util.Queue<EvaluatedSearchGraphPath<N,A,V>> getSolutionQueue()

getExpandedCounter

public int getExpandedCounter()

Check how many times a node was expanded.

Returns:

A counter of how many times a node was expanded.

getCreatedCounter

public int getCreatedCounter()

getFValue

public V getFValue(N node)

getFValue

public V getFValue(BackPointerPath<N,A,V> node)

getNodeAnnotations

public java.util.Map<java.lang.String,java.lang.Object> getNodeAnnotations(N node)

getNodeAnnotation

public java.lang.Object getNodeAnnotation(N node,
                                          java.lang.String annotation)

onFValueReceivedEvent

public void onFValueReceivedEvent(FValueEvent<V> event)

getConfig

public IBestFirstConfig getConfig()

Specified by:

getConfig in interface org.api4.java.algorithm.IAlgorithm<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,N>

Overrides:

getConfig in class ai.libs.jaicore.basic.algorithm.AAlgorithm<I extends org.api4.java.ai.graphsearch.problem.IPathSearchWithPathEvaluationsInput<N,A,V>,EvaluatedSearchGraphPath<N,A,V extends java.lang.Comparable<V>>>

toDetailedString

public java.lang.String toDetailedString()

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object