Reuse allocations in common filters

[j178]

Reuse existing vectors when filtering hooks and npm pack results, and strip workspace prefixes from run filenames in place to avoid copying the whole batch.

[codecov]

Codecov Report

❌ Patch coverage is 96.36364% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 93.64%. Comparing base (98e2252) to head (077c7f5).

Files with missing lines	Patch %	Lines
crates/prek/src/cli/run/filter.rs	94.28%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2548      +/-   ##
==========================================
- Coverage   93.65%   93.64%   -0.01%     
==========================================
  Files         134      134              
  Lines       28886    28901      +15     
==========================================
+ Hits        27052    27065      +13     
- Misses       1834     1836       +2     

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[Copilot]

Pull request overview

This PR reduces allocation churn in common CLI filtering paths by reusing existing Vec buffers during hook and filename filtering, and by stripping workspace prefixes from run filenames in place to avoid rebuilding the whole list.

Changes:

• Reuse Vec allocations via retain/retain_mut for npm pack archive selection and hook filtering.
• Strip workspace-relative prefixes from RunInput file paths in place (including non-UTF8-safe handling) and add platform-specific tests.
• Simplify list/run hook filtering by mutating the existing hook list instead of allocating new vectors.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
crates/prek/src/languages/node/node.rs	Reuses the archives vector and filters in place when selecting the .tgz produced by npm pack.
crates/prek/src/cli/run/run.rs	Filters selected hooks in place for stage/message-file compatibility, avoiding additional allocations.
crates/prek/src/cli/run/filter.rs	Strips workspace prefixes from collected filenames in place and adds non-UTF8 preservation tests for Unix/Windows.
crates/prek/src/cli/list.rs	Filters hooks in place for the list command, avoiding a separate filtered_hooks allocation.

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[prek-ci-bot]

📦 Cargo Bloat Comparison

Binary size change: +0.00% (30.4 MiB → 30.4 MiB)

Expand for cargo-bloat output

Head Branch Results

 File  .text     Size             Crate Name
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_encrypt_avx512
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  85.7KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  57.6KiB              prek prek::run::{closure#0}
 0.2%   0.4%  55.0KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.3%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.1%   0.3%  40.8KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  34.3KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  32.6KiB              prek <prek::languages::ruby::installer::RubyInstaller>::install::{closure#0}
 0.1%   0.2%  30.9KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  30.5KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  28.6KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  27.2KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  27.2KiB              prek <prek::languages::mise::installer::MiseInstaller>::download::{closure#0}
 0.1%   0.2%  26.6KiB              prek prek::cli::try_repo::try_repo::{closure#0}
 0.1%   0.2%  24.9KiB               xml <xml::reader::parser::PullParser>::dispatch_token
 0.1%   0.2%  24.2KiB              prek <<prek::config::LocalHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  23.5KiB              prek <<prek::config::UpdateOptions as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
43.1%  88.5%  13.1MiB                   And 26774 smaller methods. Use -n N to show more.
48.6% 100.0%  14.8MiB                   .text section size, the file size is 30.4MiB

Base Branch Results

 File  .text     Size             Crate Name
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_encrypt_avx512
 1.1%   2.2% 332.0KiB        aws_lc_sys aws_lc_0_43_0_aes_gcm_decrypt_avx512
 0.3%   0.6%  86.0KiB              prek <prek::cli::Command as clap_builder::derive::Subcommand>::augment_subcommands
 0.2%   0.4%  57.4KiB              prek prek::run::{closure#0}
 0.2%   0.4%  55.0KiB              prek <<prek::config::Config as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.2%   0.3%  49.4KiB annotate_snippets annotate_snippets::renderer::render::render
 0.1%   0.3%  46.2KiB              prek <prek::languages::ruby::installer::RubyInstaller>::install::{closure#0}
 0.1%   0.3%  39.2KiB              prek prek::cli::run::run::run::{closure#0}
 0.1%   0.2%  34.8KiB              prek <prek::languages::node::installer::NodeInstaller>::install::{closure#0}
 0.1%   0.2%  34.3KiB              prek <prek::cli::RunOptions as clap_builder::derive::Args>::augment_args
 0.1%   0.2%  33.0KiB              prek <prek::languages::golang::installer::GoInstaller>::install::{closure#0}
 0.1%   0.2%  31.9KiB              prek <prek::languages::bun::installer::BunInstaller>::install::{closure#0}
 0.1%   0.2%  30.9KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  30.5KiB     granit_parser <granit_parser::scanner::Scanner<granit_parser::input::str::StrInput>>::fetch_more_tokens
 0.1%   0.2%  29.2KiB              prek <prek::languages::deno::installer::DenoInstaller>::download::{closure#0}
 0.1%   0.2%  28.6KiB    cargo_metadata <&mut serde_json::de::Deserializer<serde_json::read::StrRead> as serde_core::de::Deserializer>::deserialize_struct::<<cargo_metadata::Package as serde_core::de::Deserialize>::deserialize::__Visitor>
 0.1%   0.2%  28.0KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble_alt
 0.1%   0.2%  27.5KiB        aws_lc_sys aws_lc_0_43_0_edwards25519_scalarmuldouble
 0.1%   0.2%  27.2KiB              prek <<prek::config::RemoteHook as serde_core::de::Deserialize>::deserialize::__Visitor as serde_core::de::Visitor>::visit_map::<<serde_saphyr::de::deserializer::YamlDeserializer as serde_core::de::Deserializer>::deserialize_map::MA>
 0.1%   0.2%  27.2KiB              prek <prek::languages::mise::installer::MiseInstaller>::download::{closure#0}
42.9%  88.3%  13.0MiB                   And 26809 smaller methods. Use -n N to show more.
48.6% 100.0%  14.8MiB                   .text section size, the file size is 30.4MiB

[prek-ci-bot]

⚡️ Hyperfine Benchmarks

Summary: 0 regressions, 0 improvements above the 10% threshold.

Environment

• OS: Linux 6.17.0-1020-azure
• CPU: 4 cores
• prek version: prek 0.4.13+4 (0cd0339 2026-08-12)
• Rust version: rustc 1.97.1 (8bab26f4f 2026-07-14)
• Hyperfine version: hyperfine 1.20.0

CLI Commands

Benchmarking basic commands in the main repo:

prek --version

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base --version	2.3 ± 0.1	2.2	2.6	1.06 ± 0.08
prek-head --version	2.2 ± 0.1	2.1	3.5	1.00

prek list

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base list	9.5 ± 0.3	9.0	10.2	1.03 ± 0.04
prek-head list	9.2 ± 0.3	8.8	10.7	1.00

prek validate-config .pre-commit-config.yaml

⏭️ Skipped: .pre-commit-config.yaml not found

prek sample-config

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base sample-config	2.7 ± 0.1	2.6	2.8	1.07 ± 0.03
prek-head sample-config	2.5 ± 0.0	2.4	2.6	1.00

Cold vs Warm Runs

Comparing first run (cold) vs subsequent runs (warm cache):

prek run --all-files (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	40.1 ± 1.0	38.5	41.5	1.03 ± 0.04
prek-head run --all-files	38.9 ± 1.3	37.5	41.5	1.00

prek run --all-files (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	39.4 ± 1.3	37.8	43.6	1.00
prek-head run --all-files	39.4 ± 1.1	37.7	41.4	1.00 ± 0.04

Full Hook Suite

Running the builtin hook suite on the benchmark workspace:

prek run --all-files (full builtin hook suite)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --all-files	39.4 ± 1.1	37.1	42.1	1.00 ± 0.05
prek-head run --all-files	39.2 ± 1.4	35.9	41.7	1.00

Individual Hook Performance

Benchmarking each hook individually on the test repo:

prek run trailing-whitespace --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run trailing-whitespace --all-files	13.6 ± 0.5	12.8	14.7	1.03 ± 0.05
prek-head run trailing-whitespace --all-files	13.2 ± 0.5	12.5	15.0	1.00

prek run end-of-file-fixer --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run end-of-file-fixer --all-files	11.5 ± 0.6	10.6	13.3	1.03 ± 0.06
prek-head run end-of-file-fixer --all-files	11.2 ± 0.4	10.5	12.0	1.00

prek run check-json --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-json --all-files	8.2 ± 0.2	7.9	8.6	1.05 ± 0.05
prek-head run check-json --all-files	7.8 ± 0.3	7.3	8.4	1.00

prek run check-yaml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-yaml --all-files	8.0 ± 0.2	7.7	8.5	1.06 ± 0.03
prek-head run check-yaml --all-files	7.5 ± 0.1	7.3	7.8	1.00

prek run check-toml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-toml --all-files	8.2 ± 0.3	7.7	9.0	1.05 ± 0.05
prek-head run check-toml --all-files	7.8 ± 0.3	7.2	8.5	1.00

prek run check-xml --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-xml --all-files	8.0 ± 0.4	7.5	9.0	1.00
prek-head run check-xml --all-files	8.1 ± 1.0	7.3	12.3	1.01 ± 0.13

prek run detect-private-key --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run detect-private-key --all-files	11.7 ± 0.8	10.7	14.2	1.06 ± 0.08
prek-head run detect-private-key --all-files	11.0 ± 0.5	10.0	12.0	1.00

prek run fix-byte-order-marker --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run fix-byte-order-marker --all-files	13.6 ± 0.8	12.2	15.1	1.02 ± 0.09
prek-head run fix-byte-order-marker --all-files	13.3 ± 1.0	12.2	16.1	1.00

Installation Performance

Benchmarking hook installation (fast path hooks skip Python setup):

prek install-hooks (cold - no cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.7 ± 0.0	4.7	4.8	1.06 ± 0.01
prek-head install-hooks	4.5 ± 0.0	4.4	4.5	1.00

prek install-hooks (warm - with cache)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base install-hooks	4.7 ± 0.1	4.6	4.8	1.07 ± 0.02
prek-head install-hooks	4.4 ± 0.0	4.3	4.5	1.00

File Filtering/Scoping Performance

Testing different file selection modes:

prek run (staged files only)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run	24.4 ± 0.4	23.9	25.0	1.02 ± 0.03
prek-head run	24.0 ± 0.5	23.3	25.4	1.00

prek run --files '*.json' (specific file type)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --files '*.json'	5.4 ± 0.1	5.3	5.5	1.07 ± 0.02
prek-head run --files '*.json'	5.1 ± 0.1	5.0	5.3	1.00

Workspace Discovery & Initialization

Benchmarking hook discovery and initialization overhead:

prek run --dry-run --all-files (measures init overhead)

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run --dry-run --all-files	7.1 ± 0.1	6.9	7.3	1.03 ± 0.02
prek-head run --dry-run --all-files	6.9 ± 0.1	6.7	7.1	1.00

Meta Hooks Performance

Benchmarking meta hooks separately:

prek run check-hooks-apply --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-hooks-apply --all-files	8.4 ± 0.1	8.3	8.6	1.04 ± 0.02
prek-head run check-hooks-apply --all-files	8.1 ± 0.1	8.0	8.4	1.00

prek run check-useless-excludes --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run check-useless-excludes --all-files	8.4 ± 0.1	8.2	8.7	1.04 ± 0.02
prek-head run check-useless-excludes --all-files	8.0 ± 0.1	7.9	8.2	1.00

prek run identity --all-files

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
prek-base run identity --all-files	7.1 ± 0.0	7.1	7.2	1.03 ± 0.01
prek-head run identity --all-files	6.9 ± 0.1	6.8	7.1	1.00

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated no new comments.

Suppressed comments (1)

crates/prek/src/cli/run/filter.rs:575

• collect_run_input previously normalized stripped filenames via fs::normalize_path(...) (to ensure / separators on Windows). With strip_prefix_in_place, the retained suffix keeps whatever separators came from git output or other sources, which can reintroduce \-separated paths and make path matching/printing inconsistent with other call sites in this module (e.g. collect_file_arguments and collect_explicit_files normalize inputs). Consider normalizing the retained suffix on Windows before rebuilding the PathBuf so RunInput::Files stays consistently normalized.

    let mut bytes = std::mem::take(path).into_os_string().into_encoded_bytes();
    drop(bytes.drain(..start));

    // SAFETY: the retained suffix is the valid `Path` returned by `strip_prefix`,
    // moved without modification and rebuilt on the same target.