perf: skip iterating over empty list

[tobias-ibounig-dt]

This PR

• Adds an early-exit guard in HookSupport.addFilteredHooks when the source collection is empty

Related Issues

None

Notes

addFilteredHooks is called four times per flag evaluation (provider, options, client, API hooks). In the common case three of those sources are empty, but a for-each loop always calls collection.iterator() before checking hasNext(), allocating a ConcurrentLinkedQueue$Itr or ArrayList$Itr unnecessarily. The isEmpty() check short-circuits before the iterator is ever created.

Metric	benchmark.txt	main	This PR	Delta vs main
run:+totalAllocatedBytes	139,359,040	107,492,056	103,293,456	−4,198,600 (−3.9%)
run:+totalAllocatedInstances	4,452,140	2,228,290	2,117,789	−110,501 (−4.9%)

Follow-up Tasks

• More PRs with memory improvements
• Update benchmark.txt after all are applied

Summary by CodeRabbit

Release Notes

• Performance

  • Improved hook handling efficiency when processing empty sources.

• Tests

  • Added test coverage for hook-source behavior with concurrent queue implementations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 3a4ce153-2c5d-4260-9e68-89a7e3445d5c

📥 Commits

Reviewing files that changed from the base of the PR and between cc837b1 and 96ee102.

📒 Files selected for processing (2)

• src/main/java/dev/openfeature/sdk/HookSupport.java
• src/test/java/dev/openfeature/sdk/HookSupportTest.java

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📝 Walkthrough

Walkthrough

HookSupport.addFilteredHooks gains an early-exit guard that returns immediately when the source collection is empty. Two new unit tests cover ConcurrentLinkedQueue hook sources: one verifies empty queues produce no hooks, and another verifies a non-empty queue contributes its hook to the result.

Changes

Empty-source early exit in HookSupport

Layer / File(s)	Summary
Early-exit guard and ConcurrentLinkedQueue tests src/main/java/dev/openfeature/sdk/HookSupport.java, src/test/java/dev/openfeature/sdk/HookSupportTest.java	addFilteredHooks returns early when source.isEmpty(). Two new tests assert that empty ConcurrentLinkedQueue sources yield no hooks and that a non-empty one contributes its hook to hookSupportData.getHooks().

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding an early-exit guard to skip iterating over empty collections in HookSupport.addFilteredHooks.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.11%. Comparing base (cc837b1) to head (96ee102).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1969      +/-   ##
============================================
+ Coverage     92.11%   93.11%   +0.99%     
- Complexity      660      664       +4     
============================================
  Files            59       59              
  Lines          1624     1626       +2     
  Branches        182      183       +1     
============================================
+ Hits           1496     1514      +18     
+ Misses           80       66      -14     
+ Partials         48       46       -2     

Flag	Coverage Δ
unittests	93.11% <100.00%> (+0.99%)	⬆️

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud