I don't know whether we want to make this change but here's some data...
Binary size:
- `main`: 30,384
- `charlie/match-phf`: 30,416
llvm-lines:
- `main`: 1,784,148
- `charlie/match-phf`: 1,789,877
llvm-lines and binary size are both unchanged (or, by < 5) when moving
from `u8` to `u32` return types, and even when moving to `char` keys and
values. I didn't expect this, but I'm not very knowledgable on this
topic.
Performance:
```
Confusables/match/src time: [4.9102 µs 4.9352 µs 4.9777 µs]
change: [+1.7469% +2.2421% +2.8710%] (p = 0.00 < 0.05)
Performance has regressed.
Found 12 outliers among 100 measurements (12.00%)
2 (2.00%) low mild
4 (4.00%) high mild
6 (6.00%) high severe
Confusables/match-with-skip/src
time: [2.0676 µs 2.0945 µs 2.1317 µs]
change: [+0.9384% +1.6000% +2.3920%] (p = 0.00 < 0.05)
Change within noise threshold.
Found 8 outliers among 100 measurements (8.00%)
3 (3.00%) high mild
5 (5.00%) high severe
Confusables/phf/src time: [31.087 µs 31.188 µs 31.305 µs]
change: [+1.9262% +2.2188% +2.5496%] (p = 0.00 < 0.05)
Performance has regressed.
Found 15 outliers among 100 measurements (15.00%)
3 (3.00%) low mild
6 (6.00%) high mild
6 (6.00%) high severe
Confusables/phf-with-skip/src
time: [2.0470 µs 2.0486 µs 2.0502 µs]
change: [-0.3093% -0.1446% +0.0106%] (p = 0.08 > 0.05)
No change in performance detected.
Found 4 outliers among 100 measurements (4.00%)
2 (2.00%) high mild
2 (2.00%) high severe
```
The `-with-skip` variants add our optimization which first checks
whether the character is ASCII. So `match` is way, way faster than PHF,
but it tends not to matter since almost all source code is ASCII anyway.
## Summary
Adds `PERF401` and `PERF402` mirroring `W8401` and `W8402` from
https://github.com/tonybaloney/perflint
Implementation is not super smart but should be at parity with upstream
implementation judging by:
c07391c176/perflint/comprehension_checker.py (L42-L73)
It essentially checks:
- If the body of a for-loop is just one statement
- If that statement is an `if` and the if-statement contains a call to
`append()` we flag `PERF401` and suggest a list comprehension
- If that statement is a plain call to `append()` or `insert()` we flag
`PERF402` and suggest `list()` or `list.copy()`
I've set the violation to only flag the first append call in a long
`if-else` statement for `PERF401`. Happy to change this to some other
location or make it multiple violations if that makes more sense.
## Test Plan
Fixtures were added with the relevant scenarios for both rules
## Issue Links
Refers: https://github.com/astral-sh/ruff/issues/4789
* Use phf for confusables to reduce llvm lines
## Summary
This replaces FxHashMap for the confusables with a perfect hash map from the [phf crate](https://github.com/rust-phf/rust-phf) to reduce the generated llvm instructions.
A perfect hash function is one that doesn't have any collisions. We can build one because we know all keys at compile time. This improves hashmap efficiency, even though this is likely not noticeable in our case (except someone has a large non-english crate to test on).
The original hashmap contained a lot of duplicates, which i had to remove when phf_map complained, i did so by sorting the keys.
The important part that it reduces the llvm instructions generated (#3808, `RUSTFLAGS="-Csymbol-mangling-version=v0" cargo llvm-lines -p ruff --lib | head -20`):
```
Lines Copies Function name
----- ------ -------------
1740502 38973 (TOTAL)
27423 (1.6%, 1.6%) 1 (0.0%, 0.0%) ruff[cef4c65d96248843]::rules::ruff::rules::confusables::CONFUSABLES::{closure#0}
10193 (0.6%, 2.2%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::codes::RuleCodePrefix>::iter
8107 (0.5%, 2.6%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::codes::Rule>::noqa_code
7345 (0.4%, 3.0%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::checkers::ast::Checker as ruff_python_ast[3778b140caf21545]::visitor::Visitor>::visit_stmt
6412 (0.4%, 3.4%) 1 (0.0%, 0.0%) <<ruff[cef4c65d96248843]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:spanned::SpannedDeserializer<toml_edit[7e3a6c5e67260672]:🇩🇪:value::ValueDeserializer>>
6412 (0.4%, 3.8%) 1 (0.0%, 0.0%) <<ruff[cef4c65d96248843]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:table::TableMapAccess>
6409 (0.4%, 4.2%) 1 (0.0%, 0.0%) <<ruff[cef4c65d96248843]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:datetime::DatetimeDeserializer>
5696 (0.3%, 4.5%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::checkers::ast::Checker as ruff_python_ast[3778b140caf21545]::visitor::Visitor>::visit_expr
4448 (0.3%, 4.7%) 1 (0.0%, 0.0%) ruff[cef4c65d96248843]::flake8_to_ruff::converter::convert
3702 (0.2%, 4.9%) 1 (0.0%, 0.0%) <&ruff[cef4c65d96248843]::registry::Linter as core[da82827a87f140f9]::iter::traits::collect::IntoIterator>::into_iter
3349 (0.2%, 5.1%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::registry::Linter>::code_for_rule
3132 (0.2%, 5.3%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::codes::Rule as core[da82827a87f140f9]::fmt::Debug>::fmt
3130 (0.2%, 5.5%) 1 (0.0%, 0.0%) <&str as core[da82827a87f140f9]::convert::From<&ruff[cef4c65d96248843]::codes::Rule>>::from
3130 (0.2%, 5.7%) 1 (0.0%, 0.0%) <&str as core[da82827a87f140f9]::convert::From<ruff[cef4c65d96248843]::codes::Rule>>::from
3130 (0.2%, 5.9%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::codes::Rule as core[da82827a87f140f9]::convert::AsRef<str>>::as_ref
3128 (0.2%, 6.0%) 1 (0.0%, 0.0%) <ruff[cef4c65d96248843]::codes::RuleIter>::get
2669 (0.2%, 6.2%) 1 (0.0%, 0.0%) <<ruff[cef4c65d96248843]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_seq::<toml_edit[7e3a6c5e67260672]:🇩🇪:array::ArraySeqAccess>
```
After:
```
Lines Copies Function name
----- ------ -------------
1710487 38900 (TOTAL)
10193 (0.6%, 0.6%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::codes::RuleCodePrefix>::iter
8107 (0.5%, 1.1%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::codes::Rule>::noqa_code
7345 (0.4%, 1.5%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::checkers::ast::Checker as ruff_python_ast[5588cd60041c8605]::visitor::Visitor>::visit_stmt
6412 (0.4%, 1.9%) 1 (0.0%, 0.0%) <<ruff[52408f46d2058296]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:spanned::SpannedDeserializer<toml_edit[7e3a6c5e67260672]:🇩🇪:value::ValueDeserializer>>
6412 (0.4%, 2.2%) 1 (0.0%, 0.0%) <<ruff[52408f46d2058296]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:table::TableMapAccess>
6409 (0.4%, 2.6%) 1 (0.0%, 0.0%) <<ruff[52408f46d2058296]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_map::<toml_edit[7e3a6c5e67260672]:🇩🇪:datetime::DatetimeDeserializer>
5696 (0.3%, 3.0%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::checkers::ast::Checker as ruff_python_ast[5588cd60041c8605]::visitor::Visitor>::visit_expr
4448 (0.3%, 3.2%) 1 (0.0%, 0.0%) ruff[52408f46d2058296]::flake8_to_ruff::converter::convert
3702 (0.2%, 3.4%) 1 (0.0%, 0.0%) <&ruff[52408f46d2058296]::registry::Linter as core[da82827a87f140f9]::iter::traits::collect::IntoIterator>::into_iter
3349 (0.2%, 3.6%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::registry::Linter>::code_for_rule
3132 (0.2%, 3.8%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::codes::Rule as core[da82827a87f140f9]::fmt::Debug>::fmt
3130 (0.2%, 4.0%) 1 (0.0%, 0.0%) <&str as core[da82827a87f140f9]::convert::From<&ruff[52408f46d2058296]::codes::Rule>>::from
3130 (0.2%, 4.2%) 1 (0.0%, 0.0%) <&str as core[da82827a87f140f9]::convert::From<ruff[52408f46d2058296]::codes::Rule>>::from
3130 (0.2%, 4.4%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::codes::Rule as core[da82827a87f140f9]::convert::AsRef<str>>::as_ref
3128 (0.2%, 4.5%) 1 (0.0%, 0.0%) <ruff[52408f46d2058296]::codes::RuleIter>::get
2669 (0.2%, 4.7%) 1 (0.0%, 0.0%) <<ruff[52408f46d2058296]::settings::options::Options as serde[d89b1b632568f5a3]:🇩🇪:Deserialize>::deserialize::__Visitor as serde[d89b1b632568f5a3]:🇩🇪:Visitor>::visit_seq::<toml_edit[7e3a6c5e67260672]:🇩🇪:array::ArraySeqAccess>
2659 (0.2%, 4.9%) 1 (0.0%, 0.0%) <&ruff[52408f46d2058296]::codes::Pylint as core[da82827a87f140f9]::iter::traits::collect::IntoIterator>::into_iter
```
I'd assume this has a positive effect both on compile time and on runtime, but i don't know the actual effect on compile times and can't really measure.
## Test plan
Check CI for any performance regressions.
This should fix#3808 if we merge it.
* clippy
* Update update_ambiguous_characters.py
* Add script for ecosystem wide checks of all rules and fixes
This adds my personal script for checking an entire checkout of ~2.1k packages for
panics, autofix errors and similar problems. It's not really meant to be used by anybody else but i thought it's better if it lives in the repo than if it doesn't.
For reference, this is the current output of failing autofixes: https://gist.github.com/konstin/c3fada0135af6cacec74f166adf87a00. Trimmed down to the useful information: https://gist.github.com/konstin/c864f4c300c7903a24fdda49635c5da9
* Keep github template intact
* Remove the need for ripgrep
* sort output
