12c6ac78e2 with fixed mistake when cache
slot is copied instead of being referenced:
```cpp
auto cache =
box.cached_intrinsic_sizes().min_content_height.ensure(width);
```
while it should've been:
```cpp
auto& cache =
box.cached_intrinsic_sizes().min_content_height.ensure(width);
```
This change moves intrinsic sizes cache from
LayoutState, which is local to current layout run,
to layout nodes, so it could be reused between
layout runs. This optimization is possible because
we can guarantee that these measurements will
remain unchanged unless the style of the element
or any of its descendants changes.
For now, invalidation is implemented simply by
resetting cache on whole ancestors chain once we
figured that element needs layout update.
The case when layout is invalidated by DOM's
structural changes is covered by layout tree
invalidation that drops intrinsic sizes cache
along with layout nodes.
I measured improvement on couple websites:
- Mail list on GMail 28ms -> 6ms
- GitHub large code page 47ms -> 36ms
- Discord chat history 15ms -> 8ms
(Time does not include `commit()`)
If the CharacterData node has no layout node when we're changing its
text, we don't need to mark the document for relayout.
This is fine, because if the node ends up getting a layout node attached
to it, we'll naturally perform relayout after that anyway.
For DevTools, we will want to forward mutation events to the UI in order
to inform the DevTools client about changed DOM nodes. The API for this
requires the new values associated with the events; for example, for
character data events, this will be the node's new text data.
This patch moves the queueing of the mutation record until after we have
the new character data stored. This is not observable.
Regressed in 036327332f.
This commit moves the optimization a little later in replaceData(),
still avoiding relayout (the important part).
Recovers 480 points on WPT. :^)
Allows us to avoid invalidating layout when CharacterData didn't change.
Results in visible improvement on Discord that continuously invokes
this function with the same data, which previously resulted in relayout
on every frame.
Currently, this metadata is only provided on the insertion steps,
though I believe it would be useful to extend to the other cases
as well. This metadata can aid in making optimizations for these
steps by providing extra context into the type of change which
was made on the child.
We do not fire `beforeinput` events since other browsers do not seem to
do so either.
The spec asks us to check whether a command's action modified the DOM
tree. This means adding or removing nodes and attributes, or changing
character data anywhere in the tree. We have
`Document::dom_tree_version()` for node updates, but for character data
a new version number is introduced that allows us to easily keep track
of any text changes in the entire tree.
When inserting a new utf-16 surrogate next to an existing surrogate
with replaceData, the surrogates would not get merged correctly into a
single code point. This is because internally the text data is stored
as utf-8, and the two surrogates would be converted seperately. This
has now been fixed by first recreating the whole string in utf-16 and
then converting it back to utf-8.
It's not the most efficient solution, but this fixes at least 6 WPT
subtests.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root
LibWeb keeps growing and the Web namespace is filling up fast.
Let's put DOM stuff into Web::DOM, just like we already started doing
with SVG stuff in Web::SVG.
