Implement some minor performance optimizations #4283
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
5ac51ff to
3de87f9
Compare
DimitrisJim
reviewed
Nov 20, 2022
coolreader18
approved these changes
Nov 21, 2022
compiler/parser/src/string.rs
Outdated
| @@ -14,6 +14,19 @@ pub fn parse_strings( | |||
| let initial_end = values[0].2; | |||
| let initial_kind = (values[0].1 .1 == StringKind::U).then(|| "u".to_owned()); | |||
|
|
|||
| // Optimization: fast-track the common case of a single string. | |||
| if values.len() == 1 && matches!(&values[0].1 .1, StringKind::Normal | StringKind::U) { | |||
There was a problem hiding this comment.
If you wanted, you could do matches!(&*values, [(_, (_, StringKind::Normal | StringKind::U), _)]) for this whole thing (or the equivalent with if-let). I find that using patterns is generally clearer for understanding the structures of tuples over using indices.
There was a problem hiding this comment.
Nice suggestion, thanks! (I still can't figure out how to take ownership of the String itself without the weird values.into_iter(), so I couldn't if-let.)
|
@coolreader18 - Definitely! We've used it from the very beginnings of Ruff. I've tried to contribute back as many compatibility improvements as I can :) |
youknowone
approved these changes
Nov 21, 2022
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
I tend to benchmark the parser by parsing all of CPython in Ruff. This involves (1) disabling Ruff's linting pass, then (2) running
cargo build --release && hyperfine --warmup 10 --runs 50 -i "./target/release/ruff resources/test/cpython --no-cache".Prior to this change:
After this change:
So it's a ~4.8% improvement, if you take the median results.
Note that there's about ~58ms of overhead associated with this benchmark (e.g., to locate all the Python files on-disk, read their contents, etc.), so that's really a lower-bound on improvement.