Optimize LongValueFacetCutter with leaf-local ordinal cache#15898
Open
RamakrishnaChilaka wants to merge 1 commit intoapache:mainfrom
Open
Optimize LongValueFacetCutter with leaf-local ordinal cache#15898RamakrishnaChilaka wants to merge 1 commit intoapache:mainfrom
RamakrishnaChilaka wants to merge 1 commit intoapache:mainfrom
Conversation
RamakrishnaChilaka
force-pushed
the
optimise_LongValueFacetCutter
branch
from
0d0884c to
6be639b
Compare
Contributor
|
This PR has not had activity in the past 2 weeks, labeling it as stale. If the PR is waiting for review, notify the dev@lucene.apache.org list. Thank you for your contribution! |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Description
LongValueFacetCutter's
nextOrd()callscomputeIfAbsent()on every document, which acquires aReadWriteLock.readLock()each time — even when the value has already been seen. With low-cardinality fields (e.g. 1K distinct values across 500K docs), ~99.8% of these lock acquisitions are wasted.This PR adds a per-leaf
LongIntHashMapthat cachesvalue → ordinalmappings. On cache hit (the common case), ordinal resolution is a plain unsynchronized hash map get. On cache miss (first occurrence of a value in the segment), it falls through to the existing lockedcomputeIfAbsentand stores the result locally.JMH Benchmark (500K docs, 1K cardinality, Corretto JDK 25.0.2)