The Cache and CacheStorage interfaces are quite intertwined. A Cache
object can only be created through CacheStorage, so the Cache interface
cannot be tested on its own. So adding just this stub will allow
implementing the CacheStorage interfaces that create Cache objects. We
can then implement the Cache interface piecemeal.
We maintain a registry of elements with an anchor-name so once they are
referenced for anchor positioning, we can find them with an O(1) lookup
instead of traversing the entire DOM tree.
No parsing yet, just CSSContainerRule and the supporting ContainerQuery
class.
CSSContainerRule is unusual in how it matches, because instead of it
either matching or not matching globally, it instead is matched against
a specific element. But also, some at-rules inside it always apply, as
if they were written outside it. This doesn't fit well with how
CSSConditionRule is implemented, and will likely require some rework
later. For now, `condition_matches()` always returns false, and
`for_each_effective_rule()` is overridden to always process those
global at-rules and nothing else.
HTMLParser::the_end() had three spin_until calls that blocked the event
loop: step 5 (deferred scripts), step 7 (ASAP scripts), and step 8
(load event delay). This replaces them with an HTMLParserEndState state
machine that progresses asynchronously via callbacks.
The state machine has three phases matching the three spin_until calls:
- WaitingForDeferredScripts: loops executing ready deferred scripts
- WaitingForASAPScripts: waits for ASAP script lists to empty
- WaitingForLoadEventDelay: waits for nothing to delay the load event
Notification triggers re-evaluate the state machine when conditions
change: HTMLScriptElement::mark_as_ready, stylesheet unblocking in
StyleElementBase/HTMLLinkElement, did_stop_being_active_document, and
DocumentLoadEventDelayer decrements. NavigableContainer state changes
(session history readiness, content navigable cleared, lazy load flag)
also trigger re-evaluation of the load event delay check.
Key design decisions and why:
1. Microtask checkpoint in schedule_progress_check(): The old spin_until
called perform_a_microtask_checkpoint() before checking conditions.
This is critical because HTMLImageElement::update_the_image_data step
8 queues a microtask that creates the DocumentLoadEventDelayer.
Without the checkpoint, check_progress() would see zero delayers and
complete before images start delaying the load event.
2. deferred_invoke in schedule_progress_check():
I tried Core::Timer (0ms), queue_global_task, and synchronous calls.
Timers caused non-deterministic ordering with the HTML event loop's
task processing timer, leading to image layout tests failing (wrong
subtest pass/fail patterns). Synchronous calls fired too early during
image load processing before dimensions were set, causing 0-height
images in layout tests. queue_global_task had task ordering issues
with the session history traversal queue. deferred_invoke runs after
the current callback returns but within the same event loop pump,
giving the right balance.
3. Navigation load event guard (m_navigation_load_event_guard): During
cross-document navigation, finalize_a_cross_document_navigation step
2 calls set_delaying_load_events(false) before the session history
traversal activates the new document. This creates a transient state
where the parent's load event delay check sees the about:blank (which
has ready_for_post_load_tasks=true) as the active document and
completes prematurely.
Previously we had two implementations for parsing
`<color-interpolation-method>`, one for gradients and one for
`color-mix()` - this commit adds another which will unify the existing
ones in following commits.
This implementation has a couple of advantages over the existing ones:
- It is simpler in that it uses global CSS enums and their helper
functions
- It is spec compliant (unlike the `color-mix()` one which allows
arbitrary idents)
- It parses as a `StyleValue` which will be required once we support
`<custom-color-space>` since that can be an `ident()` which isn't
resolvable at parse time
We were conflating elements being the active element and elements being
activated. The :active pseudo class is supposed to be based on whether
an element will have its activation behavior run upon a button being
released.
Store whether an element is being activated as a flag that is set/reset
by EventHandler.
Doing this allows label elements to visually activate their control
without doing a weird paintable hack, so the Labelable classes have
been yeeted.
Previously, after one request was marked as processed, we would
synchronously queue another task to process the next request. This
would mean that two open requests on the same database could
interleave. This was especially problematic when one of the requests
would cause the database to upgrade, since the second open request
would begin processing before the upgradeneeded event fired, causing an
exception to be thrown in the second open().
The solution is to explicitly check for continuation conditions after
events have been fired in order to ensure that every step for the
request is completed before starting any further request processing.
For connection requests, the spec states:
> Open requests are processed in a connection queue. The queue contains
> all open requests associated with an storage key and a name. Requests
> added to the connection queue processed in order and each request
> must run to completion before the next request is processed. An open
> request may be blocked on other connections, requiring those
> connections to close before the request can complete and allow
> further requests to be processed.
For requests against a transaction, the spec states:
> Once the transaction has been started the implementation can begin
> executing the requests placed against the transaction. Requests must
> be executed in the order in which they were made against the
> transaction. Likewise, their results must be returned in the order
> the requests were placed against a specific transaction. There is no
> guarantee about the order that results from requests in different
> transactions are returned.
In the process of reworking it to use this approach, I've added a bunch
of new tests that cover things that our imported WPTs weren't checking.
With the fix for serializing connection requests, we can now fully
download the assets for the emscripten-compiled asm.js games in the
Humble Mozilla Bundle, particularly FTL: Faster Than Light.
There were no regressions in our test suite. One web platform test,
'idbindex_reverse_cursor.any.html', has one newly-failing subtest, but
the subtest was apparently only passing by chance due synchronous
execution of requests. A few web platform tests that were added in a
prior commit improved. The delete-request-queue.any.html test has
stopped crashing, and the close-in-upgrade-needed.any.html test has
stopped flaking, so they are both imported here as well.
Incidentally fixes#7512, for which a crash test has been added.
The tricky bit of this is resolving cycles in extending rules and
ensuring that counter styles are registered in the required order for
extension (i.e. for any pair of extended/extending rules the extended
one should be registered first).
Many CSS grammars call for us to parse `Foo || Bar` but we don't have a
good way to represent this unless we have a custom style value. Usually
we store the values in a `StyleValueList` but since that can only store
non-null elements we have to manually recheck which elements we have at
which index whenever we use it.
This style value holds a Vector of `RefPtr<StyleValue const>` so that we
can represent null values and know what values are at what index without
manually rechecking.
These were moved in 0f04c6d but the namespace remained the same. We also
now forward declare these in `AK/Forward.h` rather than
`LibWeb/Forward.h` (or not at all in the case of `ValueComparingRefPtr`)
Two related problems exist in the current display list architecture:
1. DrawPaintingSurface thread safety: CanvasPaintable::paint() records
the *same* PaintingSurface that the canvas rendering context draws
to. The rendering thread later reads from it, but the main thread
may be concurrently drawing — a data race.
2. Video frames force display list rebuilds: each new video frame
triggers set_needs_display() → full display list rebuild.
Both stem from display list commands holding direct references to
content (surface/bitmap) rather than going through an indirection
layer.
ExternalContentSource is a thread-safe, atomically-refcounted
container that holds an ImmutableBitmap snapshot. The accompanying
DrawExternalContent display list command reads from it during replay,
so producers can swap in new content without rebuilding the list.
Subsequent commits migrate canvas, video, and SVG painting to
ExternalContentSource and then remove DrawPaintingSurface.
This means we don't need to include `FilterValueListStyleValue.h` in as
many places - reducing the rebuild from editing that file from 717 files
to 19.
Replace per-element OrderedHashMap storage for custom properties with
a RefCounted chain (CustomPropertyData) that enables structural
sharing. Each chain node stores only the properties declared directly
on its element, with a parent pointer to the inherited chain.
Elements that don't override any custom properties share the parent's
data directly (just a RefPtr copy). During cascade, only entries that
actually differ from the parent are stored in own_values - the rest
are inherited through the chain. During var() resolution, resolved
values are compared against the parent's and matching entries are
dropped, enabling further sharing.
The chain uses a depth limit (max 32) with flattening, plus
absorption of small parent nodes (threshold 8) to keep lookups fast.
This reduces custom property memory from ~79 MB to ~5.7 MB on
cloudflare.com.
Previously we parsed it as `<custom-ident>` in `<counter>` and as a
keyword in `list-style-type`.
The practical effect of this is:
- Spec defined counter style names in `<counter>` are ASCII lowercased
on parse.
- Non spec defined counter style names are allowed in `list-style-type.
We are still to parse the `symbols()` function but this gives us a
better base for that.
Remove includes from Node.h that are only needed for forward
declarations (AccessibilityTreeNode.h, XMLSerializer.h,
JsonObjectSerializer.h). Extract StyleInvalidationReason and
FragmentSerializationMode enums into standalone lightweight
headers so downstream headers (CSSStyleSheet.h, CSSStyleProperties.h,
HTMLParser.h) can include just the enum they need instead of all of
Node.h. Replace Node.h with forward declarations in headers that only
use Node by pointer/reference.
This breaks the circular dependency between Node.h and
AccessibilityTreeNode.h, reducing AccessibilityTreeNode.h's
recompilation footprint from ~1399 to ~25 files.
Remove 11 heavy includes from Document.h that were only needed for
pointer/reference types (already forward-declared in Forward.h), and
extract the nested ViewportClient interface to a standalone header.
This reduces Document.h's recompilation cascade from ~1228 files to
~717 files (42% reduction). Headers like BrowsingContext.h that were
previously transitively included see even larger improvements (from
~1228 down to ~73 dependents).
When the mouse is dragged from inside a scrollable container to outside
of it, we now automatically scroll the container so the selection can be
extended. Scroll speed scales with the distance past the scrollport
edge, capped at a maximum. Edges close to the viewport boundary get a
wider activation zone so the speed ramp works predictably even when the
mouse has limited room to move.
The logic is encapsulated in AutoScrollHandler, which EventHandler
creates lazily on mouse selection start.
Replace the direct #include of StyleInvalidation.h in Element.h with a
forward declaration in Forward.h. Element.h only uses the type in
function declarations, so the complete type is not needed.
This reduces the recompilation impact of modifying StyleInvalidation.h
from ~1380 files to ~4 files, since Element.h is transitively included
by nearly every HTML and SVG element header.
Previously, any SVG geometry attribute change would mark the entire
document layout tree as dirty, triggering a full layout pass even though
only the SVG subtree was affected. This made SVG geometry animations
unnecessarily expensive.
Fix this by stopping `needs_layout_update` propagation at the SVGSVGBox
boundary and tracking dirty SVG roots separately on the Document. When
`update_layout()` finds that only SVG roots need relayout (and the
document layout root is clean), it runs SVGFormattingContext on each
dirty SVG root in a fresh LayoutState and commits the results directly,
bypassing the full document layout pass entirely.
This results in a substantial performance improvement on pages with
animated SVGs, such as https://www.cloudflare.com/,
https://www.duolingo.com/, and our GC graph explorer page.
