Make JsStr<'a> directly use variants instead of pointers
#4572
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
This is the first in a series of PR to improve the performance of strings in Boa. The first step was to introduce a new type of strings, `SliceString`, which contains a strong pointer to another string and start/end indices. This allows for very fast slicing of strings. This initially came at a performance cost by having an enumeration of kinds of strings. An intermediate experiment was introduced to have the kind be a tag on the internal JsString pointer. This still came as a cost as it required bit operations to figure out which function to call. Finally, I moved to using a `vtable`. This helped with many points: 1. as fast as before. Before this PR, there was still a deref of a pointer when accessing internal fields. 2. we can now introduce many other types (which will come in their separate PRs). 3. this makes the code to clone/drop/as_str (and even construction) more streamline as each function is their own implementation.
String should never change length anyway, they are immutable in our current design.
This allows us to add more variants, like ASCII, later.
…latin1-and-utf16-string-3
Test262 conformance changes
New panics (3): |
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #4572 +/- ##
===========================================
+ Coverage 47.24% 57.28% +10.04%
===========================================
Files 476 509 +33
Lines 46892 58018 +11126
===========================================
+ Hits 22154 33238 +11084
- Misses 24738 24780 +42 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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.
This allows us to add more variants, like ASCII, later.