org.cpsolver.ifs.assignment.context

Class NeighbourSelectionWithContext<V extends Variable<V,T>,T extends Value<V,T>,C extends AssignmentContext>

java.lang.Object

org.cpsolver.ifs.assignment.context.NeighbourSelectionWithContext<V,T,C>

Type Parameters:

V - Variable

T - Value

C - Assignment Context

All Implemented Interfaces:

CanHoldContext, HasAssignmentContext<V,T,C>, NeighbourSelection<V,T>

Direct Known Subclasses:

ExamConstruction, ExamGreatDeluge, ExamHillClimbing, ExamNeighbourSelection, ExamSimulatedAnnealing, ExamTabuSearch, FixCompleteSolutionNeighbourSelection, MaxIdleNeighbourSelection, MetaHeuristicSearch, NeighbourSearch, ParallelConstruction, SimpleSearch

public abstract class NeighbourSelectionWithContext<V extends Variable<V,T>,T extends Value<V,T>,C extends AssignmentContext>
extends Object
implements NeighbourSelection<V,T>, HasAssignmentContext<V,T,C>, CanHoldContext

A neighborhood selection with an assignment context. In order to be able to hold multiple assignments in memory it is desired for all the assignment dependent data a selection may need (to keep its current state), to store these data in a separate class (implementing the AssignmentContext interface). This context is created by calling HasAssignmentContext.createAssignmentContext(Assignment) and accessed by ConstraintWithContext.getContext(Assignment).

Version:

IFS 1.3 (Iterative Forward Search)
Copyright (C) 2014 Tomáš Müller
muller@unitime.org
http://muller.unitime.org

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not see http://www.gnu.org/licenses.

Author:

Tomáš Müller

See Also:

AssignmentContext

Field Summary

Fields

Modifier and Type	Field and Description
protected C	iContextOverride

Fields inherited from interface org.cpsolver.ifs.assignment.context.CanHoldContext

sMaxSize

Constructor Summary

Constructors

Constructor and Description
NeighbourSelectionWithContext()

Method Summary

Modifier and Type	Method and Description
AssignmentContextReference<V,T,C>	getAssignmentContextReference() Returns an assignment context reference
AssignmentContext[]	getContext() An array of CanHoldContext.sMaxSize assignment contexts
C	getContext(Assignment<V,T> assignment) Returns an assignment context associated with this selection.
boolean	hasContextOverride() Has context override
void	init(Solver<V,T> solver) Criterion initialization
protected boolean	isSingleContextSolver(Solver<V,T> solver) Returns true if there should be only one context for this neighbourhood selection.
void	setAssignmentContextReference(AssignmentContextReference<V,T,C> reference) Store an assignment context reference that was given for the class by the Model.createReference(HasAssignmentContext).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cpsolver.ifs.heuristics.NeighbourSelection

selectNeighbour

Methods inherited from interface org.cpsolver.ifs.assignment.context.HasAssignmentContext

createAssignmentContext

Field Detail

iContextOverride

protected C extends AssignmentContext iContextOverride

Constructor Detail

NeighbourSelectionWithContext

public NeighbourSelectionWithContext()

Method Detail

init

public void init(Solver<V,T> solver)

Description copied from interface: NeighbourSelection

Criterion initialization

Specified by:

init in interface NeighbourSelection<V extends Variable<V,T>,T extends Value<V,T>>

Parameters:

solver - current solver

isSingleContextSolver

protected boolean isSingleContextSolver(Solver<V,T> solver)

Returns true if there should be only one context for this neighbourhood selection.

Parameters:

solver - current solver

Returns:

Solver.hasSingleSolution()

getContext

public C getContext(Assignment<V,T> assignment)

Returns an assignment context associated with this selection. If there is no assignment context associated with this selection yet, one is created using the HasAssignmentContext.createAssignmentContext(Assignment) method. From that time on, this context is kept with the assignment.

Specified by:

getContext in interface HasAssignmentContext<V extends Variable<V,T>,T extends Value<V,T>,C extends AssignmentContext>

Parameters:

assignment - given assignment

Returns:

assignment context associated with this selection and the given assignment

getAssignmentContextReference

public AssignmentContextReference<V,T,C> getAssignmentContextReference()

Description copied from interface: HasAssignmentContext

Returns an assignment context reference

Specified by:

getAssignmentContextReference in interface HasAssignmentContext<V extends Variable<V,T>,T extends Value<V,T>,C extends AssignmentContext>

Returns:

reference provided by the model by calling Model.createReference(HasAssignmentContext) during initialization

setAssignmentContextReference

public void setAssignmentContextReference(AssignmentContextReference<V,T,C> reference)

Description copied from interface: HasAssignmentContext

Store an assignment context reference that was given for the class by the Model.createReference(HasAssignmentContext).

Specified by:

setAssignmentContextReference in interface HasAssignmentContext<V extends Variable<V,T>,T extends Value<V,T>,C extends AssignmentContext>

Parameters:

reference - reference provided by the model by calling Model.createReference(HasAssignmentContext) during initialization

getContext

public AssignmentContext[] getContext()

Description copied from interface: CanHoldContext

An array of CanHoldContext.sMaxSize assignment contexts

Specified by:

getContext in interface CanHoldContext

Returns:

assignment contexts

hasContextOverride

public boolean hasContextOverride()

Has context override

Returns:

true if all threads are using the same context