[LUCENE-10534] MinFloatFunction / MaxFloatFunction calls exists twice

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 9.2
• Lucene Fields: New
• Assignee: Kevin Risden
• Reporter: Kevin Risden
• Created: 25/Apr/22 19:19
• Updated: 28/Aug/22 16:39
• Resolved: 02/May/22 17:16

Description

MinFloatFunction (https://github.com/apache/lucene/blob/main/lucene/queries/src/java/org/apache/lucene/queries/function/valuesource/MinFloatFunction.java) and MaxFloatFunction (https://github.com/apache/lucene/blob/main/lucene/queries/src/java/org/apache/lucene/queries/function/valuesource/MaxFloatFunction.java) both check if values exist twice. This change prevents the duplicate exists check.

Tested with JMH here: https://github.com/risdenk/lucene-jmh

Benchmark	Mode	Cnt	Score and Error	Units
-----------------------------------------------------------------	-------		------------------	-------
MyBenchmark.testMaxFloatFunction	thrpt	25	64.159 ± 2.031	ops/s
MyBenchmark.testNewMaxFloatFunction	thrpt	25	94.997 ± 2.365	ops/s
MyBenchmark.testMaxFloatFunctionRareField	thrpt	25	244.921 ± 6.439	ops/s
MyBenchmark.testNewMaxFloatFunctionRareField	thrpt	25	239.288 ± 5.136	ops/s

Issue Links

• is related to: LUCENE-10542 FieldSource exists implementations can avoid value retrieval
• relates to: LUCENE-5961 FunctionValues.exist(int) isn't returning false in cases where it should for many "math" based value sources
• relates to: LUCENE-7407 Explore switching doc values to an iterator API
• links to: GitHub Pull Request #837
• links to: GitHub Pull Request #840