performance: cache existsSync results in PackageCache.ownerOfFile #3
+16
−1
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Outdated suggestions cannot be applied.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.
Similar to embroider-build#1608
A lot of time is being spent in
PackageCache#ownerOfFile
and a good chunk of that is from the calls toexistsSync
:Before:

By caching access, the amount of time in
existsSync
drops considerably, From ~12 seconds to under 500ms.After:

Even so, this path is still so hot that there's a good deal of time in
ownerOfFile
and the newgetCachedExistsSync
methods that isn't accounted for byexistsSync
. There's probably more that can be done here.