[PERF] BundleWriter: Improve performance #534
Merged
Conversation
This file contains 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
The ENDS_WITH_NEW_LINE RegExp is quite slow on large strings. Therefore the "endsWithNewLine" state is computed after every modification to the "buf" in order to improve performance.
|
I like this |
codeworrior
previously requested changes
Oct 21, 2020
lib/lbt/bundle/BundleWriter.js
Outdated
| } | ||
| if ( writeBuf.length >= 1 ) { | ||
| this.buf += writeBuf; | ||
| this.endsWithNewLine = ENDS_WITH_NEW_LINE.test(writeBuf); |
There was a problem hiding this comment.
This can give wrong results when write is called with blanks or tabs only. In that case, the old endsWithNewLine flag must be taken into account as well.
Correct would be something like
ENDS_WITH_NEW_LINE.test(writeBuf) || (this.endsWithNewLine && !writeBuf.trim())
Instead of the trim(), one could use another RegExp /^[ \t]*$/
There was a problem hiding this comment.
Sounds right 👍🏻
As there were no dedicated unit tests, I've added one to cover the whole class.
RandomByte
reviewed
Oct 22, 2020
Co-authored-by: Merlin Beutlberger <m.beutlberger@sap.com>
RandomByte
approved these changes
Oct 22, 2020
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Outdated suggestions cannot be applied.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.
The ENDS_WITH_NEW_LINE RegExp is quite slow on large strings.
Therefore the "endsWithNewLine" state is computed after every modification
to the "buf" in order to improve performance.
Measurements
Based on sap.m build in SAP/openui5@0d95920
ui5 build --exclude-task="*" --include-task=generateLibraryPreloadui5 build --exclude-task="*" --include-task=generateLibraryPreload