[charliermarsh]

Diagnostics with a single annotation or sub-diagnostic currently allocate space for four entries on the first insertion. Reserve space for one initially and let the vectors grow normally when additional entries are added.

[astral-sh-bot]

Memory usage report

Summary

Project	Old	New	Diff	Outcome
flake8	38.57MB	38.57MB	-0.01% (3.77kB)	⬇️
sphinx	174.54MB	174.46MB	-0.04% (75.94kB)	⬇️
trio	94.68MB	94.51MB	-0.18% (173.37kB)	⬇️
prefect	482.22MB	480.92MB	-0.27% (1.30MB)	⬇️

Significant changes

Click to expand detailed breakdown

flake8

Name	Old	New	Diff	Outcome
check_file_impl	30.41kB	26.64kB	-12.41% (3.77kB)	⬇️

sphinx

Name	Old	New	Diff	Outcome
check_file_impl	317.49kB	244.13kB	-23.11% (73.36kB)	⬇️
infer_expression_types_impl	11.81MB	11.81MB	-0.02% (2.11kB)	⬇️
infer_scope_types_impl	6.24MB	6.23MB	-0.00% (240.00B)	⬇️
infer_definition_types	11.97MB	11.97MB	-0.00% (240.00B)	⬇️

trio

Name	Old	New	Diff	Outcome
check_file_impl	625.66kB	453.82kB	-27.47% (171.84kB)	⬇️
infer_expression_types_impl	6.08MB	6.08MB	-0.02% (1.48kB)	⬇️
infer_definition_types	4.80MB	4.80MB	-0.00% (48.00B)	⬇️

prefect

Name	Old	New	Diff	Outcome
check_file_impl	6.89MB	5.60MB	-18.69% (1.29MB)	⬇️
infer_expression_types_impl	24.17MB	24.16MB	-0.04% (9.26kB)	⬇️
infer_scope_types_impl	19.75MB	19.75MB	-0.00% (720.00B)	⬇️
infer_definition_types	38.41MB	38.41MB	-0.00% (576.00B)	⬇️

[astral-sh-bot]

ecosystem-analyzer results

No diagnostic changes detected ✅

Full report with detailed diff (timing results)

[astral-sh-bot]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

[codspeed]

Merging this PR will improve performance by 19.13%

⚡ 10 improved benchmarks
✅ 209 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Memory	linter/all-with-preview-rules[unicode/pypinyin.py]	203.9 KB	161.1 KB	+26.61%
⚡	Memory	linter/all-rules[unicode/pypinyin.py]	199.3 KB	158 KB	+26.16%
⚡	Memory	linter/all-with-preview-rules[large/dataset.py]	1,091.1 KB	893.6 KB	+22.09%
⚡	Memory	linter/all-rules[large/dataset.py]	1,061.7 KB	873.7 KB	+21.52%
⚡	Memory	linter/all-with-preview-rules[pydantic/types.py]	624.9 KB	522.4 KB	+19.62%
⚡	Memory	linter/all-with-preview-rules[numpy/ctypeslib.py]	299.1 KB	251.4 KB	+18.99%
⚡	Memory	linter/all-rules[pydantic/types.py]	607.4 KB	510.7 KB	+18.93%
⚡	Memory	linter/all-rules[numpy/ctypeslib.py]	271.1 KB	232.3 KB	+16.71%
⚡	Memory	linter/all-with-preview-rules[numpy/globals.py]	58.8 KB	52.9 KB	+11.07%
⚡	Memory	linter/all-rules[numpy/globals.py]	58 KB	52.4 KB	+10.69%

Tip

Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing charlie/28944-diagnostic-memory (73f9f3c) with main (a1f59fb)}

[MichaReiser]

Neat. I also wondered if it made sense for us to use SmallVec in some places, given that Diagnostics are Arced