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/*
* This file is part of choco-solver, http://choco-solver.org/
*
* Copyright (c) 2023, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.solver;
import org.chocosolver.memory.IEnvironment;
import org.chocosolver.solver.constraints.ISatFactory;
import org.chocosolver.solver.constraints.PropagatorPriority;
import org.chocosolver.solver.constraints.real.Ibex;
import org.chocosolver.solver.search.strategy.Search;
import org.chocosolver.solver.search.strategy.strategy.AbstractStrategy;
import org.chocosolver.util.ESat;
import java.util.HashMap;
import java.util.function.Function;
import java.util.function.IntPredicate;
import java.util.function.Predicate;
/**
* Settings for Model and Solver.
* Can be modified programmatically
* and can be defined in a Model only on creation.
*
* Project: choco-solver.
*
* @author Charles Prud'homme
* @since 14/12/2017.
*/
public class Settings {
private Predicate modelChecker = s -> !ESat.FALSE.equals(s.isSatisfied());
private boolean cloneVariableArrayInPropagator = true;
private boolean enableViews = true;
private int maxDomSizeForEnumerated = 1 << 16;
private int minCardForSumDecomposition = 50;
private boolean enableTableSubstitution = true;
private int maxTupleSizeForSubstitution = 10_000;
private boolean sortPropagatorActivationWRTPriority = true;
private int maxPropagatorPriority = PropagatorPriority.VERY_SLOW.getValue();
private Function> defaultSearch = Search::defaultSearch;
private boolean warnUser = false;
private boolean enableDecompositionOfBooleanSum = false;
private IntPredicate enableIncrementalityOnBoolSum = i -> i > 10;
private boolean enableSAT = false;
private boolean swapOnPassivate = true;
private boolean checkDeclaredConstraints = true;
private boolean checkDeclaredViews = true;
private boolean checkDeclaredMonitors = true;
private boolean printAllUndeclaredConstraints = false;
private byte hybridEngine = 0b00;
private int nbMaxLearnt = 100_000;
private int maxLearntCardinlity = Integer.MAX_VALUE / 100;
private float clauseReductionRatio = .5f;
private int dominancePerimeter = 4;
private boolean explainGlobalFailureInSum = false;
private double ibexContractionRatio = Ibex.RATIO;
private boolean ibexRestoreRounding = Ibex.PRESERVE_ROUNDING;
private Function initSolver = Solver::new;
private final HashMap additionalSettings = new HashMap<>();
private Settings() {
}
/**
* Create a new instance of `Settings` which can then be adapted to requirements.
*
* @return a Settings with default values
* @see #dev()
* @see #prod()
*/
public static Settings init() {
return new Settings();
}
/**
* Define and returns settings adapted to production environment.
* All checks and warnings are turned off.
*
* @return a settings adapted to production environment.
*/
public static Settings prod() {
return Settings.init()
.setModelChecker(s -> true)
.setWarnUser(false)
.setCheckDeclaredConstraints(false)
.setCheckDeclaredViews(false)
.setCheckDeclaredMonitors(false)
.setPrintAllUndeclaredConstraints(false);
}
/**
* Define and returns settings adapted to development environment.
* All checks and warnings are turned on.
*
* @return a settings adapted to development environment.
*/
public static Settings dev() {
return Settings.init()
.setModelChecker(s -> !ESat.FALSE.equals(s.isSatisfied()))
.setWarnUser(true)
.setCheckDeclaredConstraints(true)
.setCheckDeclaredViews(true)
.setCheckDeclaredMonitors(true)
.setPrintAllUndeclaredConstraints(true);
}
/**
* @param solver the solver
* @return true if the model is OK wrt the checker, false otherwise
*/
public boolean checkModel(Solver solver) {
return modelChecker.test(solver);
}
/**
* Define what to do when a solution is found. By default, it makes a weak check of the model:
*
* {@code
* return !ESat.FALSE.equals(solver.isSatisfied());
* }
*
* A hard check of the model can be done like this:
*
* {@code
* return ESat.TRUE.equals(solver.isSatisfied());
* }
*
*
* @param modelChecker a predicate to check the solution
* @return the current instance
*/
public Settings setModelChecker(Predicate modelChecker) {
this.modelChecker = modelChecker;
return this;
}
/**
* @return true if all propagators should clone the input variable array instead of simply referencing it.
*/
public boolean cloneVariableArrayInPropagator() {
return cloneVariableArrayInPropagator;
}
/**
* If this setting is set to true (default value), a clone of the input variable array is made in any propagator constructors.
* This prevents, for instance, wrong behavior when permutations occurred on the input array (e.g., sorting variables).
* Setting this to false may limit the memory consumption during modelling.
*
* @param cloneVariableArrayInPropagator {@code true} to clone variables array on constructor
* @return the current instance
*/
public Settings setCloneVariableArrayInPropagator(boolean cloneVariableArrayInPropagator) {
this.cloneVariableArrayInPropagator = cloneVariableArrayInPropagator;
return this;
}
/**
* @return true if views are enabled.
*/
public boolean enableViews() {
return enableViews;
}
/**
* Set to 'true' to allow the creation of views in the {@link org.chocosolver.solver.Model}.
* Creates new variables with channeling constraints otherwise.
*
* @param enableViews {@code true} to enable views
* @return the current instance
*/
public Settings setEnableViews(boolean enableViews) {
this.enableViews = enableViews;
return this;
}
/**
* @return maximum domain size threshold to force integer variable to be enumerated
*/
public int getMaxDomSizeForEnumerated() {
return maxDomSizeForEnumerated;
}
/**
* Define the minimum number of cardinality threshold to a sum/scalar constraint to be decomposed in intermediate
* sub-sums.
*
* @param maxDomSizeForEnumerated cardinality threshold
* @return the current instance
*/
public Settings setMaxDomSizeForEnumerated(int maxDomSizeForEnumerated) {
this.maxDomSizeForEnumerated = maxDomSizeForEnumerated;
return this;
}
/**
* @return minimum number of cardinality threshold to a sum constraint to be decomposed
*/
public int getMinCardForSumDecomposition() {
return minCardForSumDecomposition;
}
/**
* Define the default minimum number of cardinality threshold to a sum/scalar constraint to be
* decomposed into intermediate sub-sums.
*
* @param defaultMinCardinalityForSumDecomposition cardinality threshold
* @return the current instance
*/
public Settings setMinCardinalityForSumDecomposition(int defaultMinCardinalityForSumDecomposition) {
this.minCardForSumDecomposition = defaultMinCardinalityForSumDecomposition;
return this;
}
/**
* @return true if some intension constraints can be replaced by extension constraints
*/
public boolean enableTableSubstitution() {
return enableTableSubstitution;
}
/**
* Define whether some intension constraints are replaced by extension constraints
*
* @param enableTableSubstitution enable table substitution
* @return the current instance
*/
public Settings setEnableTableSubstitution(boolean enableTableSubstitution) {
this.enableTableSubstitution = enableTableSubstitution;
return this;
}
/**
* @return maximum domain size threshold to replace intension constraints by extension constraints
*/
public int getMaxTupleSizeForSubstitution() {
return maxTupleSizeForSubstitution;
}
/**
* Define the maximum domain size threshold to replace intension constraints by extension constraints
* Only checked when {@link #enableTableSubstitution()} returns {@code true}
*
* @param maxTupleSizeForSubstitution threshold to substitute intension constraint by table one.
* @return the current instance
*/
public Settings setMaxTupleSizeForSubstitution(int maxTupleSizeForSubstitution) {
this.maxTupleSizeForSubstitution = maxTupleSizeForSubstitution;
return this;
}
/**
* @return {@code true} if propagators are sorted wrt their priority on initial activation.
*/
public boolean sortPropagatorActivationWRTPriority() {
return sortPropagatorActivationWRTPriority;
}
/**
* Set whether propagators are sorted wrt their priority in {@link org.chocosolver.solver.propagation.PropagationEngine} when
* dealing with propagator activation.
*
* @param sortPropagatorActivationWRTPriority {@code true} to allow sorting static propagators.
* @return the current instance
*/
public Settings setSortPropagatorActivationWRTPriority(boolean sortPropagatorActivationWRTPriority) {
this.sortPropagatorActivationWRTPriority = sortPropagatorActivationWRTPriority;
return this;
}
/**
* @return the maximum priority any propagators can have (default is 7)
*/
public int getMaxPropagatorPriority(){
return maxPropagatorPriority;
}
/**
* Increase the number of priority for propagators (default is {@link PropagatorPriority#VERY_SLOW}).
* This directly impacts the number of queues to schedule propagators in the propagation engine.
*
* @param maxPropagatorPriority the new maximum prioirity any propagator can declare
* @return the current instance
*/
public Settings setMaxPropagatorPriority(int maxPropagatorPriority){
this.maxPropagatorPriority = maxPropagatorPriority;
return this;
}
/**
* Creates a default search strategy for the input model
*
* @param model a model requiring a default search strategy
* @return a default search strategy for model
* @see Search#defaultSearch(Model)
*/
public AbstractStrategy makeDefaultSearch(Model model) {
return defaultSearch.apply(model);
}
/**
* Define a default search strategy for the input model
*
* @param defaultSearch what default search strategy should be
* @return the current instance
*/
public Settings setDefaultSearch(Function> defaultSearch) {
this.defaultSearch = defaultSearch;
return this;
}
/**
* @return true if warnings detected during modeling/solving are output.
*/
public boolean warnUser() {
return warnUser;
}
/**
* To be informed of warnings detected during modeling/solving
*
* @param warnUser {@code true} to be print warnings on console
* @return the current instance
*/
public Settings setWarnUser(boolean warnUser) {
this.warnUser = warnUser;
return this;
}
/**
* @return {@code true} if boolean sum should be decomposed into an equality constraint and an arithmetic constraint,
* {@code false}if a single constraint should be used instead.
*/
public boolean enableDecompositionOfBooleanSum() {
return enableDecompositionOfBooleanSum;
}
/**
* Define if boolean sums should be decomposed into an equality constraint + arithmetic constraint
*
* @param enableDecompositionOfBooleanSum {@code true} to enable decomposition
* @return the current instance
*/
public Settings setEnableDecompositionOfBooleanSum(boolean enableDecompositionOfBooleanSum) {
this.enableDecompositionOfBooleanSum = enableDecompositionOfBooleanSum;
return this;
}
/**
* @param nbvars number of variables in the constraint
* @return {@code true} if the incrementality is enabled on boolean sum, based on the number of variables involved.
*/
public boolean enableIncrementalityOnBoolSum(int nbvars) {
return enableIncrementalityOnBoolSum.test(nbvars);
}
/**
* Define the predicate to choose incremental sum, based on number variables declared
*
* @param enableIncrementalityOnBoolSum predicate to pick declare sum
* @return the current instance
*/
public Settings setEnableIncrementalityOnBoolSum(IntPredicate enableIncrementalityOnBoolSum) {
this.enableIncrementalityOnBoolSum = enableIncrementalityOnBoolSum;
return this;
}
/**
* @return true when an underlying SAT solver is used to manage clauses declared through {@link ISatFactory},
* false when clauses are managed with CSP constraints only.
*/
public boolean enableSAT() {
return enableSAT;
}
/**
* Indicate if clauses are managed by a unique SAT solver.
*
* @param enableSAT {@code true} to rely on SAT Solver to handle clauses
* @return the current instance
*/
public Settings setEnableSAT(boolean enableSAT) {
this.enableSAT = enableSAT;
return this;
}
/**
* @return true if, on propagator passivation, the propagator is swapped from active to passive in its variables' propagators list.
* false if, on propagator passivation, only the propagator's state is set to PASSIVE.
*/
public boolean swapOnPassivate() {
return swapOnPassivate;
}
/**
* Define if passivation of propagator swap it in variables' list
*
* @param swapOnPassivate {@code true} to enable swapping
* @return the current instance
*/
public Settings setSwapOnPassivate(boolean swapOnPassivate) {
this.swapOnPassivate = swapOnPassivate;
return this;
}
/**
* @return true (default value) to check if all declared constraints are not free anymore,
* that is either posted or reified, before running the resolution.
* false to skip the control.
*/
public boolean checkDeclaredConstraints() {
return checkDeclaredConstraints;
}
/**
* Indicate if the declared constraints are either posted or reified.
*
* @param checkDeclaredConstraints {@code true} to check constraints before resolution
* @return the current instance
*/
public Settings setCheckDeclaredConstraints(boolean checkDeclaredConstraints) {
this.checkDeclaredConstraints = checkDeclaredConstraints;
return this;
}
/**
* @return true to list all undeclared constraint, false (default value) otherwise.
* Only active when {@link #checkDeclaredConstraints()} is on.
*/
public boolean printAllUndeclaredConstraints() {
return printAllUndeclaredConstraints;
}
/**
* Indicate if all undeclared constraints are listed on console when {@link #checkDeclaredConstraints()} is on.
*
* @param printAllUndeclaredConstraints {@code true} to list all undeclared constraints
* @return the current instance
*/
public Settings setPrintAllUndeclaredConstraints(boolean printAllUndeclaredConstraints) {
this.printAllUndeclaredConstraints = printAllUndeclaredConstraints;
return this;
}
/**
* @return true (default value) to check prior to creation
* if a view already semantically exists.
*/
public boolean checkDeclaredViews() {
return checkDeclaredViews;
}
/**
* Check if a view already semantically exists before creating it.
*
* @param checkDeclaredViews {@code true} to check views before creation
* @return the current instance
*/
public Settings setCheckDeclaredViews(boolean checkDeclaredViews) {
this.checkDeclaredViews = checkDeclaredViews;
return this;
}
public Settings setCheckDeclaredMonitors(boolean check) {
this.checkDeclaredMonitors = check;
return this;
}
public boolean checkDeclaredMonitors() {
return this.checkDeclaredMonitors;
}
/**
* This method is called in {@link Model#Model(IEnvironment, String, Settings)} to create the
* solver to associate with a model.
*
* @param model a model to initialize with a solver
* @return the new solver
*/
public Solver initSolver(Model model) {
return initSolver.apply(model);
}
/**
* Define the solver initialization
*
* @param initSolver function to initialize the solver
* @return the current instance
*/
public Settings setInitSolver(Function initSolver) {
this.initSolver = initSolver;
return this;
}
/**
* @return 0b00 if constraint-oriented propagation engine,
* 0b01 if hybridization between variable and constraint oriented and
* 0b10 if variable-oriented.
*/
public byte enableHybridizationOfPropagationEngine() {
return hybridEngine;
}
/**
* Define behavior of the propagation engine.
*
* @param hybrid When set to '0b00', this works as a constraint-oriented propagation engine;
* when set to '0b01', this workds as an hybridization between variable and constraint oriented
* propagation engine.
* when set to '0b10', this workds as a variable- oriented propagation engine.
* @return the current instance
*/
public Settings setHybridizationOfPropagationEngine(byte hybrid) {
this.hybridEngine = hybrid;
return this;
}
/**
* @return maximum number of learnt clauses to store. When reached, a reduction is applied.
* @see #setNbMaxLearntClauses(int)
* @see #setRatioForClauseStoreReduction(float)
* @see #getRatioForClauseStoreReduction()
* @see #setMaxLearntClauseCardinality(int)
* @see #getMaxLearntClauseCardinality()
*/
public int getNbMaxLearntClauses() {
return nbMaxLearnt;
}
/**
* Set the maximum of number of learnt clauses to store before running a reduction of the store.
*
* @param n maximum number of learnt clauses before reducing the store.
* @return the current instance
* @see #getNbMaxLearntClauses()
* @see #setRatioForClauseStoreReduction(float)
* @see #getRatioForClauseStoreReduction()
* @see #setMaxLearntClauseCardinality(int)
* @see #getMaxLearntClauseCardinality()
*/
public Settings setNbMaxLearntClauses(int n) {
this.nbMaxLearnt = n;
return this;
}
/**
* when clauses store need to be reduced, 'ratio' of them are kept (between 0.1 and .99)
*
* @see #setRatioForClauseStoreReduction(float)
* @see #setNbMaxLearntClauses(int)
* @see #getNbMaxLearntClauses()
* @see #setMaxLearntClauseCardinality(int)
* @see #getMaxLearntClauseCardinality()
*/
public float getRatioForClauseStoreReduction() {
return this.clauseReductionRatio;
}
/**
* when clauses store need to be reduced, 'ratio' of them are kept (between 0.1 and .99).
* A call to this defines 'ratio'.
*
* @param f ratio for clause store reduction
* @return the current instance
* @see #getRatioForClauseStoreReduction()
* @see #setNbMaxLearntClauses(int)
* @see #getNbMaxLearntClauses()
* @see #setMaxLearntClauseCardinality(int)
* @see #getMaxLearntClauseCardinality()
*/
public Settings setRatioForClauseStoreReduction(float f) {
this.clauseReductionRatio = f;
return this;
}
/**
* @return maximum learnt clause cardinality, clauses beyond this value are ignored.
* @see #setMaxLearntClauseCardinality(int)
* @see #setNbMaxLearntClauses(int)
* @see #setRatioForClauseStoreReduction(float)
* @see #getRatioForClauseStoreReduction()
* @see #setRatioForClauseStoreReduction(float)
*/
public int getMaxLearntClauseCardinality() {
return maxLearntCardinlity;
}
/**
* Set the maximum learnt clause cardinality, clauses beyond this value are ignored.
*
* @param n maximum learnt clause cardinality.
* @return the current instance
* @see #getMaxLearntClauseCardinality()
* @see #getNbMaxLearntClauses()
* @see #setRatioForClauseStoreReduction(float)
* @see #getRatioForClauseStoreReduction()
* @see #setRatioForClauseStoreReduction(float)
*/
public Settings setMaxLearntClauseCardinality(int n) {
maxLearntCardinlity = n;
return this;
}
/**
* When a clause is learnt from a conflict, it may happen that it dominates previously learnt ones.
* The dominance will be evaluated with the n last learnt clauses.
* n = 0 means no dominance check, n = {@link Integer#MAX_VALUE} means checking all clauses with the last one.
*
* @return dominance perimeter
*/
public int getLearntClausesDominancePerimeter() {
return dominancePerimeter;
}
/**
* When a clause is learnt from a conflict, it may happen that it dominates previously learnt ones.
* The dominance will be evaluated with the n last learnt clauses.
* n = 0 means no dominance check, n = {@link Integer#MAX_VALUE} means checking all clauses with the last one.
*
* @return dominance perimeter
*/
public Settings setLearntClausesDominancePerimeter(int n) {
this.dominancePerimeter = n;
return this;
}
/**
* @return true if additional clauses can be learned from sum's global failure
*/
public boolean explainGlobalFailureInSum() {
return explainGlobalFailureInSum;
}
/**
* Set to true to allow additional clauses to be learned from sum's global failure
*/
public Settings explainGlobalFailureInSum(boolean b) {
this.explainGlobalFailureInSum = b;
return this;
}
/**
* @return the ratio that a domains must be contracted by ibex to compute the constraint.
*/
public double getIbexContractionRatio() {
return ibexContractionRatio;
}
/**
* Defines the ratio that real domains must be contracted by ibex
* to compute the constraint. A contraction is considered as significant
* when at least {@param ratio} of a domain has been reduced.
* If the contraction is not meet, then it is considered as insufficient
* and therefore ignored. A too small ratio can degrade the ibex performance.
* The default value is 1% (0.01). See issue #653.
*
* Example: given x = [0.0, 100.0], y = [0.5,0.5] and CSTR(x > y)
* - When the ratio is 1% (0.01) bounds of X are kept as [0.0, 100.0]
* because it's contraction is less than 1%.
* - When the ratio is 0.1% (0.001) bounds of X are update to [0.5, 100.0]
* because it's contraction is greater than 0.1%.
*
* @param ibexContractionRatio defines the ratio that a domains must be
* contract to compute the constraint.
* @implNote Supported since ibex-java version 1.2.0
*/
public void setIbexContractionRatio(double ibexContractionRatio) {
this.ibexContractionRatio = ibexContractionRatio;
}
/**
* If preserve_rounding is true, Ibex will restore the default
* Java rounding method when coming back from Ibex, which is
* transparent for Java but causes a little loss of efficiency.
* To improve the running time, ibex changes the rounding system
* for double values during contraction. In Linux/MACOS environments
* it leads to different results in calculations like `Math.pow(10, 6)`.
* See issue #740.
*
* @param ibexRestoreRounding either Java or ibex rounding method
* @implNote Supported since ibex-java version 1.2.0
*/
public Settings setIbexRestoreRounding(boolean ibexRestoreRounding) {
this.ibexRestoreRounding = ibexRestoreRounding;
return this;
}
/**
* @return if ibex must restore java rounding mode when returning a call.
*/
public boolean getIbexRestoreRounding() {
return ibexRestoreRounding;
}
public Object get(String key) {
return additionalSettings.get(key);
}
public Settings set(String key, Object value) {
this.additionalSettings.put(key, value);
return this;
}
}