OptaPlanner's score calculator callbacks for entities

Question

My model supports real-time change by Solver#addProblemFactChange and ProblemFactChange interface. Implementing doChange method of this interface, I actively use notifications of scoreDirector by methods like beforeEntityRemoved, beforeProblemFactRemoved, beforeProblemFactChanged and other. Besides, incremental score calculator of model implements callback methods beforeEntityAdded, beforeEntityRemoved and their after-versions.

Investigating solver behavior, I saw such diagram of score calculator calls from optaplanner:

Callbacks call diagram

That is optaplanner doesn't invoke entities related methods of calculator despite model changes. Why so occurs and why necessary to notify scoreDirector?

That diagram doesn't look right... or I am intepreting/parsing it incorrectly. Standardizing on an UML sequence diagram should remove my parsing issues. — Geoffrey De Smet, Apr 24 '15 at 07:22
@GeoffreyDeSmet Yes, my diagram isn't canonical. I use it only to show absence of some callbacks. Correct sequence diagram already exist [in docs](http://docs.jboss.org/optaplanner/release/6.2.0.Final/optaplanner-docs/html_single/images/Chapter-Score_calculation/incrementalScoreCalculatorSequenceDiagram.png). — injecto, Apr 24 '15 at 08:09

score 1 · Accepted Answer · answered Apr 24 '15 at 07:19

The ProblemFactChange api has been designed to allow incremental changes to the problem, therefore you need to call before|afterProblemFactAdded|Changed|Removed(), otherwise implementing incremental problem changes with be impossible (without changing the API).

It's the ScoreDirector's responsibility to handle those events:

DroolsScoreDirector works incrementally for problem facts too (not just planning variables).
IncrementalScoreDirector does not do it incrementally yet for problem facts (but it does for planning variables). There is just some stopgap code with a TODO there in 6.2, which works but doesn't work as fast as it should.

I created a jira issue to track this issue.

OptaPlanner's score calculator callbacks for entities

1 Answers1