Package ai.timefold.solver.core.api.solver

Enum Class SolutionUpdatePolicy

java.lang.Object
java.lang.Enum<SolutionUpdatePolicy>
ai.timefold.solver.core.api.solver.SolutionUpdatePolicy
All Implemented Interfaces:
Serializable, Comparable<SolutionUpdatePolicy>, Constable
public enum SolutionUpdatePolicy extends Enum<SolutionUpdatePolicy>
To fully de-normalize a planning solution freshly loaded from persistent storage, two operations need to happen:
  • Variable listeners need to run, reading the state of all entities and computing values for their shadow variables.
  • Score needs to be calculated and stored on the planning solution.

Each of these operations has its own performance cost, and for certain use cases, only one of them may be actually necessary. Advanced users therefore get a choice of which to perform.

If unsure, pick UPDATE_ALL.

  • Enum Constant Details

    • UPDATE_ALL

      public static final SolutionUpdatePolicy UPDATE_ALL
      Combines the effects of UPDATE_SCORE_ONLY and UPDATE_SHADOW_VARIABLES_ONLY, in effect fully updating the solution.

    • UPDATE_SCORE_ONLY

      public static final SolutionUpdatePolicy UPDATE_SCORE_ONLY
      Calculates the score based on the entities in the solution, and writes it back to the solution. Does not update shadow variables, making the user responsible for ensuring that all shadow variables are mutually consistent. Otherwise the results of the computation are undefined, and may range from the wrong score being computed to runtime exceptions being thrown. To avoid this issue, use UPDATE_ALL instead, which will update shadow variables to their correct values first.

    • UPDATE_SHADOW_VARIABLES_ONLY

      public static final SolutionUpdatePolicy UPDATE_SHADOW_VARIABLES_ONLY
      Runs variable listeners on all planning entities and problem facts, updates shadow variables. Does not update score; the solution will keep the current score, even if it is stale or null. To avoid this, use UPDATE_ALL instead.

    • NO_UPDATE

      public static final SolutionUpdatePolicy NO_UPDATE
      Does not run anything. Improves performance during SolutionManager.analyze(Object, ScoreAnalysisFetchPolicy, SolutionUpdatePolicy) and SolutionManager.explain(Object, SolutionUpdatePolicy), where the user can guarantee that the solution is already up to date. Otherwise serves no purpose.

  • Method Details

    • values

      public static SolutionUpdatePolicy[] values()
      Returns an array containing the constants of this enum class, in the order they are declared.
      Returns:
      an array containing the constants of this enum class, in the order they are declared

    • valueOf

      public static SolutionUpdatePolicy valueOf(String name)
      Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)
      Parameters:
      name - the name of the enum constant to be returned.
      Returns:
      the enum constant with the specified name
      Throws:
      IllegalArgumentException - if this enum class has no constant with the specified name
      NullPointerException - if the argument is null

    • isScoreUpdateEnabled

      public boolean isScoreUpdateEnabled()

    • isShadowVariableUpdateEnabled

      public boolean isShadowVariableUpdateEnabled()
      If this is true, variable listeners will ignore certain fail-fasts. See InnerScoreDirector.expectShadowVariablesInCorrectState().
      Returns:
      true if shadow variables should be updated