Make Classes cheap to clone #3021
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
![github-actions[bot]](https://avatars.githubusercontent.com/in/15368?s=60&v=4){kind=small}
cecton
commented
Dec 6, 2022
packages/yew/src/html/classes.rs
Outdated
Comment on lines
36
to
40
| // NOTE: this can be improved once Iterator::intersperse() becomes stable | ||
| for class in rest { | ||
| s.push_str(" "); | ||
| s.push_str(class.as_str()); | ||
| } |
There was a problem hiding this comment.
I had to change this because class.as_str() borrows on class and the compiler refused to yield the borrow value 😞 not a big deal
cecton
commented
Dec 6, 2022
| @@ -60,7 +67,7 @@ impl Classes { | |||
| if self.is_empty() { | |||
| *self = classes_to_add | |||
| } else { | |||
| self.set.extend(classes_to_add.set) | |||
| Rc::make_mut(&mut self.set).extend(classes_to_add.set.iter().cloned()) | |||
There was a problem hiding this comment.
The use of Rc::make_mut() is important here as it will avoid cloning the set if it's not necessary
|
Visit the preview URL for this PR (updated for commit 4275574): https://yew-rs-api--pr3021-cecton-make-classes-1inatn7g.web.app (expires Wed, 14 Dec 2022 00:50:47 GMT) 🔥 via Firebase Hosting GitHub Action 🌎 |
cecton
commented
Dec 6, 2022
Comment on lines
104
to
112
| fn into_prop_value(self) -> AttrValue { | ||
| let mut classes = self.set.iter(); | ||
| let mut classes = self.set.iter().cloned(); | ||
|
|
||
| match classes.next() { | ||
| None => AttrValue::Static(""), | ||
| Some(class) if classes.len() == 0 => match *class { | ||
| Cow::Borrowed(class) => AttrValue::Static(class), | ||
| Cow::Owned(ref class) => AttrValue::Rc(Rc::from(class.as_str())), | ||
| }, | ||
| Some(first) => AttrValue::Rc(Rc::from(build_string(first, classes.map(Cow::borrow)))), | ||
| Some(class) if classes.len() == 0 => class, | ||
| Some(first) => build_attr_value(first, classes), | ||
| } | ||
| } |
There was a problem hiding this comment.
Some of the code has become simpler thanks to the cloning
cecton
commented
Dec 6, 2022
Comment on lines
152
to
157
| fn into_iter(self) -> Self::IntoIter { | ||
| self.set.into_iter() | ||
| // NOTE: replace this by Rc::unwrap_or_clone() when it becomes stable | ||
| Rc::try_unwrap(self.set) | ||
| .unwrap_or_else(|rc| (*rc).clone()) | ||
| .into_iter() | ||
| } |
There was a problem hiding this comment.
Shamelessly copy-pasted from std. I will take no question
Benchmark - SSRYew Master
Pull Request
|
Size Comparison
|
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.
Description
The goal of this PR is to make
Classescheap to clone. My motivation is toimprove the use of
Classesin UI toolkits likeyewprint. In Yewprint, the user can pass
classes to a component like this:
The next thing Yew will do is to render the actual button to a child component
as you can see here:
This is inefficient at the moment because all the class values (can be
Cow::Owned) are cloned unnecessarily.To make it more efficient, I'm proposing 2 major changes to the
Classesobject:
use AttrValue instead of Cow in Classes
Cowis cheap to clone only when the value is a&'static str. UsingAttrValuehere (aka IString) will allow owned string to be clonedefficiently, thanks to the use of
AttrValue::Rc.wrap indexset into Rc
In most cases, classes will be added to the user classes before being
passed to the child component. But there are cases where classes are passed
as is to the child component. In that case, it is unnecessary to clone the
internal
IndexSetitself.Checklist
I have added tests[edit: I have not added test because the API does notchange at all and the current tests are already covering all the use cases.]