[LUCENE-6365] Optimized iteration of finite strings

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 5.0
• Fix Version/s: 5.3, 6.0
• Component/s: core/other
• Labels: patch performance
• Lucene Fields: New, Patch Available
• Assignee: Unassigned
• Reporter: Markus Heiden
• Created: 18/Mar/15 12:14
• Updated: 28/Aug/22 14:29
• Resolved: 06/Jul/15 18:39

Description

Replaced Operations.getFiniteStrings() by an optimized FiniteStringIterator.

Benefits:
Avoid huge hash set of finite strings.
Avoid massive object/array creation during processing.

"Downside":
Iteration order changed, so when iterating with a limit, the result may differ slightly. Old: emit current node, if accept / recurse. New: recurse / emit current node, if accept.

The old method Operations.getFiniteStrings() still exists, because it eases the tests. It is now implemented by use of the new FiniteStringIterator.