[LUCENE-6228] Do not expose full-fledged scorers in LeafCollector.setScorer

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 8.0
• Lucene Fields: New
• Assignee: Alan Woodward
• Reporter: Adrien Grand
• Created: 09/Feb/15 14:24
• Updated: 28/Aug/22 14:24
• Resolved: 04/Sep/18 10:03

Description

Currently LeafCollector.setScorer takes a Scorer, which I don't like because several methods should never be called in the context of a Collector (like nextDoc or advance).

I think it's even more trappy for methods that might seem to work in some particular cases but will not work in the general case, like getChildren which will not work if you have a specialized BulkScorer or iterating over positions which will not work if you are in a MultiCollector and another leaf collector consumes positions too.

So I think we should restrict what can be seen from a collector to avoid such traps.

Issue Links

• relates to: LUCENE-6959 Remove ToParentBlockJoinCollector