Instead of returning HeapBlock memory to the kernel (or a non-type
specific shared cache), we now keep a BlockAllocator per CellAllocator
and implement "deallocation" by basically informing the kernel that we
don't need the physical memory right now.
This is done with MADV_FREE or MADV_DONTNEED if available, but for other
platforms (including SerenityOS) we munmap and then re-mmap the memory
to achieve the same effect. It's definitely clunky, so I've added a
FIXME about implementing the madvise options on SerenityOS too.
The important outcome of this change is that GC types that use a
type-specific allocator become immune to use-after-free type confusion
attacks, since their virtual addresses will only ever be re-used for
the same exact type again and again.
Fixes#22274
In XYZ space, gray doesn't have three equal values. Instead, it is
a line through the whitepoint.
(Multiplying by the whitepoint has the same effect as multiplying
the sRGB matrix with a (g, g, g) vector, since the numbers on
the matrix's rows add up to the whitepoint.)
Fixes the very slight red tint on all the figures in chapter 4
of the PDF 1.7 spec.
We were previously only checking the first value, this is wrong for tags
that accept multiple values (e.g. ExtraSamples) and can lead to crashes
on malformed images containing tags with a count of 0.
The TIFF spec is constructed in a way that many tags are defined in
multiple places but some of these definitions are partial. If we look
into "Section 8: Baseline Field Reference Guide", we can see that these
tags indeed have an enforced length of 1.
Using a vector to represent a list of painting commands results in many
reallocations, especially on pages with a lot of content.
This change addresses it by introducing a SegmentedVector, which allows
fast appending by representing a list as a sequence of fixed-size
vectors. Currently, this new data structure supports only the
operations used in RecordingPainter, which are appending and iterating.
This is quite niche, but lets us convert parsing methods to accepting
TokenStream, while still being able to call them when we just have a
lone token. Specifically we'll use this in the next commit, but it's
likely to also be useful as a stop-gap measure when converting more
parsing methods.
Frequently we want to parse "anything that's a `<length-percentage>`" or
similar, which could be a constant value or a calculation, but didn't
have a nice way of doing so. That meant repeating the same "try and
parse a dimension, see if it's the right type, then maybe try and parse
a calculation and see if that's the right type" boilerplate code. Or
more often, forgetting about calculations entirely.
These helpers should make that a lot more convenient to do. And they
also use TokenStream, so we can eventually drop the old `parse_length()`
method.
All DOM node mutation IPCs now invoke an async completion IPC after the
DOM is mutated. This allows consolidating where the Inspector updates
its view and the selected DOM node.
This also allows improving the response to removing a DOM node. We would
previously just select the <body> tag after removing a DOM node because
the Inspector client had no idea what node preceded the removed node.
Now the WebContent process can just indicate what that node is. So now
after removing a DOM node, we inspect either its previous sibling (if it
had one) or its parent.
Rename them from "did_get_*" to "did_inspect_*", to correspond to the
request methods "inspect_dom_tree" and "inspect_accessibility_tree". No
functional change, but this makes it a bit easier to stare at IPC files
side-by-side and know which response method corresponds to a request
method at a quick glance.
With this change, we create substantially fewer border painting
commands, which means fewer reallocations of the vector that stores
commands.
This makes the rendering of
https://html.spec.whatwg.org/multipage/browsing-the-web.html visibly
faster, where we allocated ~10 of such commands now vs ~8000 before.
We already have the src attribute stored as a String, so it's completely
wasteful to convert it to a ByteString. We were even doing it twice when
loading each image.
When resolving a rope, we've already taken care to resolve it to
a UTF-8 byte stream. There's no need to do a separate pass just for
validating the data again.
This was noticeable in some profiles. I made a simple microbenchmark
that gets a 30% speed-up:
("x" + "y".repeat(100_000_000)).trimStart()
UTF8Decoder was already converting invalid data into replacement
characters while converting, so we know for sure we have valid UTF-8
by the time conversion is finished.
This patch adds a new StringBuilder::to_string_without_validation()
and uses it to make UTF8Decoder avoid half the work it was doing.
Instead of using a StringBuilder, add a String::repeated(String, N)
overload that takes advantage of knowing it's already all UTF-8.
This makes the following microbenchmark go 4x faster:
"foo".repeat(100_000_000)
And for single character strings, we can even go 10x faster:
"x".repeat(100_000_000)
The fix here was to stop using StringBuilder::append(char) when told to
append a code point, and switch to StringBuilder::append_code_point(u32)
There's probably a bunch more issues like this, and we should stop using
append(char) in general since it allows building of garbage strings.
I noticed while debugging a fully downloaded page that it was trying
to preconnect to a file:// host. That doesn't make any sense, so let's
add a tiny bit of logic to ignore preconnect requests for file: and
data: URLs.
With this change, instead of applying scroll offsets during the
recording of the painting command list, we do the following:
1. Collect all boxes with scrollable overflow into a PaintContext,
each with an id and the total amount of scrolling offset accumulated
from ancestor scrollable boxes.
2. During the recording phase assign a corresponding scroll_frame_id to
each command that paints content within a scrollable box.
3. Before executing the recorded commands, translate each command that
has a scroll_frame_id by the accumulated scroll offset.
This approach has following advantages:
- Implementing nested scrollables becomes much simpler, as the
recording phase only requires the correct assignment of the nearest
scrollable's scroll_frame_id, while the accumulated offset from
ancestors is applied subsequently.
- The recording of painting commands is not tied to a specific offset
within scrollable boxes, which means in the future, it will be
possible to update the scrolling offset and repaint without the need
to re-record painting commands.
The decoder assumes that k's sampling factor matches y's at the moment.
Better to error out than to silently render something broken.
For ycck, covered by ycck-2111.jpg in the tests.
This scan code set is more advanced than the basic scan code set 1, and
is required to be supported for some bare metal hardware that might not
properly enable the PS2 first port translation in the i8042 controller.
LibWeb can now also generate bindings for keyboard events like the Pause
key, as well as other function keys (such as Right Alt, etc).
The logic for handling scan code sets is implemented by the PS2 keyboard
driver and is abstracted from the main HID KeyboardDevice code which
only handles "standard" KeyEvent(s).
Instead of using a scan code, which for scan code set 2 will not
represent the expected character mapping index, we could just use
another variable in the KeyEvent structure that correctly points to the
character index.
This change is mostly relevant to the KeyboardMapper application, and
also to the WindowServer code, as both handle KeyEvents and need to
use the character mapping index in various situations.
We currently assume that the K (black) channel uses the same sampling
as the Y channel already, so this already works as long as we don't
error out on it.
We can now implement steps related to resizable ArrayBuffer objects. We
can also implement a couple of missing SharedArrayBuffer checks.
The original implementation of this proposal did not have any tests, so
tests are added here for the whole implementation.
