[LUCENE-7350] Let classifiers be constructed from IndexReaders

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.4, 7.0
• Component/s: modules/classification
• Lucene Fields: New
• Assignee: Tommaso Teofili
• Reporter: Tommaso Teofili
• Created: 21/Jun/16 11:03
• Updated: 28/Aug/22 15:00
• Resolved: 21/Jun/16 11:12

Description

Current Classifier implementations are built from LeafReaders, this is an heritage of using certain Lucene 4.x AtomicReader's specific APIs; this is no longer required as what is used by current implementations is based on IndexReader APIs and therefore it makes more sense to use that as constructor parameter as it doesn't give any additional benefit whereas it requires client code to deal with classifiers that are tight to segments (which doesn't make much sense).