"return" method is not defined on any of builtin iterators, so we could
skip it, avoiding method lookup.
I measured 10% improvement in array-destructuring-assignment.js micro
benchmark with this change.
...by avoiding `{ value, done }` iterator result value allocation. This
change applies the same otimization 81b6a11 added for `for..in` and
`for..of`.
Makes following micro benchmark go 22% faster on my computer:
```js
function f() {
const arr = [];
for (let i = 0; i < 10_000_000; i++) {
arr.push([i]);
}
let sum = 0;
for (let [i] of arr) {
sum += i;
}
}
f();
```
The editing command that relies the most on this, `insertLinebreak`,
did not perform a layout update after inserting a `<br>` which caused
this algorithm to always return false. But instead of actually building
the layout tree needlessly, we can check the DOM tree instead.
Before this change, IDAT data was mistakenly always included in the
animation. Now we only include frames with explicit fcTL chunks.
As per the PNG spec (third edition):
"The static image may be included as the first frame of the animation
by the presence of a single fcTL chunk before IDAT. Otherwise, the
static image is not part of the animation."
We also fall back to the IDAT data when APNG has acTL but no fcTL
chunks. Test image is 062.png from fDAT-inherits-cICP.html from WPT.
The assertion in `WebSocketImplCurl::did_connect()` keeps failing for
multiple websockets when loading `https://www.speedtest.net/` since
commit 14ebcd4. This fixes that by checking and returning false if
something went wrong and letting the caller function handle it.
Introduce special instruction for `for..of` and `for..in` loop that
skips `{ value, done }` result object allocation if iterator is builtin
(array, map, set, string). This reduces GC pressure significantly and
avoids extracting the `value` and `done` properties.
This change makes this micro benchmark 48% faster on my computer:
```js
const arr = new Array(10_000_000);
let counter = 0;
for (let _ of arr) {
counter++;
}
```
Expose a method on built-in iterators that allows retrieving the next
iteration result without allocating a JS::Object. This change is a
preparation for optimizing for..of and for..in loops.
This is a LibWeb special. We keep running into cases where we end up
with one or more Platform or event loop spin_until() calls on the stack
after the event loop has been cancelled and the WebContent process has
been asked to exit.
To prevent too much nonsense from exiting processes early from affecting
our other, more well-behaved processes, put this special logic in the
critical path of such Web-specific event loop spins.
This method was removed in e015a43b51
However, it was not exactly *unused* as the commit message would say.
This method was the only thing that allowed spin_until to exit when
the event loop was cancelled. This happens normally when IPC connections
are closed, but also when the process is killed.
The logic to properly handle process exit from event loop spins needs to
actually notify the caller that their goal condition was not met though.
That will be handled in a later commit.
We currently store Web::Fetch::Infrastructure::Response objects in the
HTTP cache. They are associated with their original realm, but when we
use a cached response, we clone it into the target realm. For example,
two <iframe> objects loading the same HTML will be in different realms.
When we clone the response, we must use the target realm throughout the
entire cloning process. We neglected to do this for the cloned response
body stream, which is cloned via teeing. The result was the the stream
for the "cloned" response was created in the original realm, causing
issues down the line when reading from that stream tried to handle read
promises on behalf of the original realm. There are protections in place
to prevent this from happening, and the cached response read would never
complete.
This is a normative change in the ECMA-262 spec. See:
de62e8d
This did not actually seem to affect our implementation as we were not
using generators here to begin with. So this patch is basically just
adding spec comments.
Attach a 'job' to the main thread event loop, trusting that the event
loop implementation will cancel it when asked to quit. This is something
that our Unix implementation does, but isn't strictly part of the
contract of EventLoopImplementation.
This reverts commit 36bb2824a6.
Although this was faster on my M3 MacBook Pro, other Apple machines
disagree, including our benchmark runner. So let's revert it.
The spec calls for a couple of very specific whitespace padding
techniques whenever we canonicalize whitespace during the execution of
editing commands, but it seems that other browsers have a simpler
strategy - let's adopt theirs!
This is a simple trick to generate better native code for access to
registers, locals, and constants. Before this change, each access had
to first dereference the member pointer in Interpreter, and then get to
the values. Now we always have a pointer directly to the values on hand.
Here's how it looks:
class StackFrame {
public:
Value get(Operand) const;
void set(Operand, Value);
private:
Value m_values[];
};
And we just place one of these as a window on top of the execution
context's array of values (registers, locals, and constants).
This is implemented by these related changes:
* The Skia alpha type 'Opaque' is selected for surfaces that were
created with the intention of not having an alpha channel.
Previously we were simply creating one with alpha.
* Clearing now happens through Skia's `clear()` which always uses the
source color's value for the result, instead of setting all values
to 0.
* CanvasRenderingContext2D selects a different clearing color based on
the `alpha` context attribute's value.
