perf(changelog): cache commit retain checks (258 times faster generation)

[aminya]

Description

This caches the commit retain checks whenever include/exclude paths are specified.

This speeds up changelog generation by 258 times in a big repository I have:

Now: 0.080 s
Before:  20.633 s

Fixes #767

It also improves handling including/excluding patterns, considering the first commit, and various other improvements.

How Has This Been Tested?

I tested this on the repository mentioned in #767

Screenshots / Logs (if applicable)

Here are the profiling flamegraphs created via #768. The bottleneck is removed after this fix is applied as seen in the above image (4366 samples to only 16 samples). After the fix, other parts of the code finally show up in the profiler.

After - Fully Cached:

After - Cached + new commit:

Before:

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (no code change)
• Refactor (refactoring production code)
• Other

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly.
• I have formatted the code with rustfmt.
• I checked the lints with clippy.
• I have added tests to cover my changes.
• All new and existing tests passed.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

Attention: Patch coverage is 83.33333% with 13 lines in your changes missing coverage. Please review.

Project coverage is 39.69%. Comparing base (4b33e7e) to head (361a0a0).
Report is 1 commits behind head on main.

Files	Patch %	Lines
git-cliff-core/src/repo.rs	85.53%	11 Missing ⚠️
git-cliff/src/lib.rs	0.00%	2 Missing ⚠️

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Additional details and impacted files

@@            Coverage Diff             @@
##             main     #772      +/-   ##
==========================================
+ Coverage   37.03%   39.69%   +2.66%     
==========================================
  Files          20       20              
  Lines        1542     1600      +58     
==========================================
+ Hits          571      635      +64     
+ Misses        971      965       -6     

Flag	Coverage Δ
unit-tests	39.69% <83.34%> (+2.66%)	⬆️

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[alerque]

Only a measly 87× faster? Pshaw nothing to see here moving along now…

[aminya]

Only a measly 87× faster? Pshaw nothing to see here moving along now…

Challenge accepted. Now 258 times faster. 😄

[aminya]

I updated the cache implementation to be more useful by caching the changed files of each commit.

This slows down the retain_commit check by ~2 times but allows reusing the cache in case the include/exclude patterns change. This is beneficial for running in monorepos where git-cliff runs multiple times to generate changelog for different subsets of the repo. This is a good trade-off in my opinion.

[orhun]

🔥

[aminya]

I fixed some bugs in the last three commits to improve the include/exclude behaviour:

• The include/exclude patterns are considered together.
• The glob patterns are normalized so that ./ doesn't make a difference in the result
• Added special case for the first commit where it has no parent

[orhun]

LGTM, can you resolve conflicts caused by #709 ? 😇

[orhun]

Awesome, thanks!