Improve performance of location data compensation #5294
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
helixbass
commented
Jan 26, 2020
| end += length | ||
| compensation | ||
| current = start | ||
| while current <= end |
Collaborator
Author
There was a problem hiding this comment.
This just changes the iteration when calculating the location data compensations for a given start/end range to iterate on start..end instead of iterating on the entire @locationDataCompensations data structure every time
Collaborator
|
So you don't need Windows to test this, just a file with Windows line endings. To make things a bit more painful, I created a copy of ✦ time cat src/nodes.coffee | coffee --stdio --compile > /dev/null
cat src/nodes.coffee 0.00s user 0.00s system 4% cpu 0.081 total
coffee --stdio --compile > /dev/null 2.21s user 0.17s system 158% cpu 1.500 total
✦ perl -p -e 's/\n/\r\n/' < src/nodes.coffee > test.coffee # https://superuser.com/a/71509/138751
✦ time cat test.coffee | coffee --stdio --compile > /dev/null
cat test.coffee 0.00s user 0.00s system 4% cpu 0.083 total
coffee --stdio --compile > /dev/null 248.14s user 1.87s system 102% cpu 4:04.77 total
✦ git checkout --track helixbass/iss5290-slow-location-data-compensation
Branch 'iss5290-slow-location-data-compensation' set up to track remote branch 'iss5290-slow-location-data-compensation' from 'helixbass'.
Switched to a new branch 'iss5290-slow-location-data-compensation'
✦ time cat test.coffee | ./bin/coffee --stdio --compile > /dev/null
cat test.coffee 0.00s user 0.00s system 2% cpu 0.127 total
./bin/coffee --stdio --compile > /dev/null 2.21s user 0.17s system 149% cpu 1.585 totalSo in this test, compiling a version of |
Merged
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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.
Fixes #5290
As discussed in that issue, performance for files with lots of "location data compensations" (eg stripped carriage returns, so all files on Windows) was blowing up because the algorithm used for calculating location data compensation was very inefficient
So this PR improves that algorithm to one that shouldn't have significant performance implications
To test, I made a copy of a decent-size source file eg
src/lexer.coffeeand converted it to have Windows-style line endings (\r\n), and ranbin/coffee -b -p [converted-filename.coffee]Before this fix, compilation was taking many seconds, and with this fix, it took less than a second
I haven't done specific performance comparisons of a file with Windows line endings when you omit the location data compensation calculation entirely vs with this new algorithm, that might be interesting as a baseline