With this change, we now have ~1200 CellAllocators across both LibJS and
LibWeb in a normal WebContent instance.
This gives us a minimum heap size of 4.7 MiB in the scenario where we
only have one cell allocated per type. Of course, in practice there will
be many more of each type, so the effective overhead is quite a bit
smaller than that in practice.
I left a few types unconverted to this mechanism because I got tired of
doing this. :^)
This patch makes it possible for JS::Object::internal_set() to populate
a CacheablePropertyMetadata, and uses this to implement a basic
monomorphic cache for the most common form of property write access.
Before this change, whenever ImageStyleValue had a non-null
`m_image_request`, it was always leaked along with everything related
to the document to which this value belongs. The issue arises due to
the use of `JS::Handle` for the image request, as it introduces a
cyclic dependency where `ImageRequest` prevents the `CSSStyleSheet`,
that owns `ImageStyleValue`, from being deallocated:
- ImageRequest
- FetchController
- FetchParams
- Window
- HTMLDocument
- HTMLHtmlElement
- HTMLBodyElement
- Text
- HTMLHeadElement
- Text
- HTMLMetaElement
- Text
- HTMLTitleElement
- Text
- HTMLStyleElement
- CSSStyleSheet
This change solves this by visiting `m_image_request` from
`visit_edges` instead of introducing new heap root by using
`JS::Handle`.
Stop worrying about tiny OOMs. Work towards #20449.
While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
This function now takes an optional out parameter for callers who would
like to what kind of property we ended up getting.
This will be used to implement inline caching for property lookups.
Also, to prepare for adding more forms of caching, the out parameter
is a struct CacheablePropertyMetadata rather than just an offset. :^)
Prior to this commit, PropertyOwningCSSStyleDeclaration::serialized()
did not include custom properties, which lead to an incomplete
`cssRule.cssText` result.
This commit makes that class also serialize the custom properties and
place them before the regular properties in the rule text.
It's not safe to allocate from the GC heap while in the constructor of a
GC heap cell. (Because if this ends up triggering a collection, we may
end up trying to call through an uninitialized vtable).
This was already done safely in the initialize() virtual in much of
LibJS and LibWeb. This patch moves the logic for prototypes, mixins,
and CSSStyleDeclaration as well.
Fixes a long-standing GC crash that was pretty easy to reproduce by
refreshing https://vercel.com/
Previously we used a parsing context with no access to the document, so
any URLs in url() functions would become invalid.
Fixes the images on Steam's store carousel, which sets
Element.style.backgroundImage to url() functions.
This relied on pulling the current realm from the main thread VM, which
requires an execution context to be on the VM's stack. This heavily
relied on the dummy execution context that is always on the stack, for
example, when parsing the UA style sheets where no JavaScript is
running.
Note that js_rope_string() has been folded into this, the old name was
misleading - it would not always create a rope string, only if both
sides are not empty strings. Use a three-argument create() overload
instead.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
Unlike ensure_web_prototype<T>(), the cached version doesn't require the
prototype type to be fully formed, so we can use it without including
the FooPrototype.h header. It's also a bit less verbose. :^)
This is a monster patch that turns all EventTargets into GC-allocated
PlatformObjects. Their C++ wrapper classes are removed, and the LibJS
garbage collector is now responsible for their lifetimes.
There's a fair amount of hacks and band-aids in this patch, and we'll
have a lot of cleanup to do after this.
The goal here is to move the parser-internal classes into this namespace
so they can have more convenient names without causing collisions. The
Parser itself won't collide, and would be more convenient to just
remain `CSS::Parser`, but having a namespace and a class with the same
name makes C++ unhappy.
We already had setProperty() but it was full of ad-hoc idiosyncracies.
This patch aligns setProperty() with the CSSOM spec and also implements
removeProperty() since that's actually needed by setProperty() now.
Some things fixed by this:
- We now support the "priority" parameter to setProperty()
- Element "style" attributes now update to reflect CSSOM mutations
When parsing the "style" attribute on elements, we'd previously ask the
CSS parser for a PropertyOwningCSSStyleDeclaration. Then we'd create a
new ElementCSSInlineStyleDeclaration and transfer the properties from
the first object to the second object.
This patch teaches the parser to make ElementCSSInlineStyleDeclaration
objects directly.
https://www.w3.org/TR/cssom/ is the more permanent home of the CSSOM
specification's latest version, and is up to date with the draft spec.
Also, https://drafts.csswg.org/ has been down multiple times recently
which made looking things up a pain.
We can reduce the amount of padding the compiler adds in order to
ensure data alignment of member variables by ordering the types in
a struct by size in decending order.
Found By PVS-Studio: https://pvs-studio.com/en/docs/warnings/v802/
There are a handful of FIXME's here, but this seems generally good.
Note that CSS *values* don't get serialized in a spec-compliant way
since we currently rely on StyleValue::to_string() which is ad-hoc.
This patch adds the setProperty(name, value) API to CSSStyleDeclaration.
Setting an invalid or empty value will cause the property to be removed
from the declaration.
Note that this only works on mutable declarations (i.e element.style)
and not on resolved declarations (i.e window.getComputedStyle(element)).
