perf: empty default for ProviderEvaluation

[tobias-ibounig-dt]

This PR

• Use ImmutableMetadata.EMPTY singleton as the default value for ProviderEvaluation.flagMetadata

Related Issues

None

Notes

Every ProviderEvaluation built without explicit metadata allocated a fresh empty ImmutableMetadata instance via @Builder.Default. Reusing the existing ImmutableMetadata.EMPTY singleton is safe because the class has no mutation methods, and FlagEvaluationDetails already uses the same singleton as its default.

Metric	benchmark.txt	main	This PR	Delta vs main
run:+totalAllocatedBytes	139,359,040	107,492,056	103,292,056	−4,200,000 (−3.9%)
run:+totalAllocatedInstances	4,452,140	2,228,290	2,109,848	−118,442 (−5.3%)

Follow-up Tasks

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

Summary by CodeRabbit

Release Notes

This release includes internal optimizations with no user-facing changes.

• Chores
  • Optimized initialization of default metadata values for improved efficiency.

[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: ab77aba4-9f05-40c8-9cf5-b5bfd459f2c0

📥 Commits

Reviewing files that changed from the base of the PR and between cc837b1 and 85b2313.

📒 Files selected for processing (1)

• src/main/java/dev/openfeature/sdk/ProviderEvaluation.java

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📝 Walkthrough

Walkthrough

In ProviderEvaluation<T>, the Lombok @Builder.Default value for the flagMetadata field is changed from ImmutableMetadata.builder().build() to the pre-existing ImmutableMetadata.EMPTY constant.

Changes

Default flagMetadata initialization

Layer / File(s)	Summary
flagMetadata default value src/main/java/dev/openfeature/sdk/ProviderEvaluation.java	The flagMetadata field's @Builder.Default value is switched from constructing a new empty ImmutableMetadata instance to referencing the shared ImmutableMetadata.EMPTY constant.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 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: using an empty default singleton for ProviderEvaluation's flagMetadata field instead of creating new instances.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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 93.10%. Comparing base (cc837b1) to head (85b2313).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1970      +/-   ##
============================================
+ Coverage     92.11%   93.10%   +0.98%     
- Complexity      660      663       +3     
============================================
  Files            59       59              
  Lines          1624     1624              
  Branches        182      182              
============================================
+ Hits           1496     1512      +16     
+ Misses           80       66      -14     
+ Partials         48       46       -2     

Flag	Coverage Δ
unittests	93.10% <ø> (+0.98%)	⬆️

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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