crate_universe: Only compile label regex once. #2751
Merged
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Outdated suggestions cannot be applied.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 hit this when profiling for something else, we spent 1.1sec of 1.3sec of
cargo-bazel generate
compiling this regular expression. It seems to be quite bad on the regex compiler, as even compiling it once takes 8ms.I had to add the
once_cell
crate to unwrap the Result type - the corresponding stdlib function is still nightly-only unfortunately. However, that crate was already in the transitive dependency tree, so it's a net-same change.