compositing: Move image output and shutdown management out of the compositor (#35538)

This is a step toward the renderer-per-WebView goal. It moves various
details out of `IOCompositor`.

- Image output: This is moved to servoshell as now applications can
  access the image contents of a `WebView` via
  `RenderingContext::read_to_image`. Most options for this are moved to
  `ServoShellPreferences` apart from `wait_for_stable_image` as this
  requires a specific kind of coordination in the `ScriptThread` that is
  also very expensive. Instead, paint is now simply delayed until a
  stable image is reached and `WebView::paint()` returns a boolean.
  Maybe this can be revisited in the future.
- Shutdown: Shutdown is now managed by libservo itself. Shutdown state
  is shared between the compositor and `Servo` instance. In the future,
  this sharing might be unecessary.
- `CompositeTarget` has been removed entirely. This no longer needs to
   be passed when creating a Servo instance.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Ngo Iok Ui (Wu Yu Wei) <yuweiwu@pm.me>
This commit is contained in:
Martin Robinson 2025-02-20 19:27:49 +01:00 committed by GitHub
parent 7d33e72bfc
commit 54b5c7b632
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
25 changed files with 233 additions and 270 deletions

View file

@ -65,7 +65,7 @@ use script_traits::{
use selectors::attr::CaseSensitivity;
use servo_arc::Arc as ServoArc;
use servo_atoms::Atom;
use servo_config::pref;
use servo_config::{opts, pref};
use servo_geometry::{f32_rect_to_au_rect, DeviceIndependentIntRect, MaxRect};
use servo_url::{ImmutableOrigin, MutableOrigin, ServoUrl};
use style::dom::OpaqueNode;
@ -368,9 +368,6 @@ pub(crate) struct Window {
/// Emits notifications when there is a relayout.
relayout_event: bool,
/// True if it is safe to write to the image.
prepare_for_screenshot: bool,
/// Unminify Css.
unminify_css: bool,
@ -2071,7 +2068,7 @@ impl Window {
// When all these conditions are met, notify the constellation
// that this pipeline is ready to write the image (from the script thread
// perspective at least).
if self.prepare_for_screenshot && updating_the_rendering {
if opts::get().wait_for_stable_image && updating_the_rendering {
// Checks if the html element has reftest-wait attribute present.
// See http://testthewebforward.org/docs/reftests.html
// and https://web-platform-tests.org/writing-tests/crashtest.html
@ -2166,7 +2163,7 @@ impl Window {
/// If writing a screenshot, synchronously update the layout epoch that it set
/// in the constellation.
pub(crate) fn update_constellation_epoch(&self) {
if !self.prepare_for_screenshot {
if !opts::get().wait_for_stable_image {
return;
}
@ -2772,7 +2769,6 @@ impl Window {
webrender_document: DocumentId,
compositor_api: CrossProcessCompositorApi,
relayout_event: bool,
prepare_for_screenshot: bool,
unminify_js: bool,
unminify_css: bool,
local_script_source: Option<String>,
@ -2862,7 +2858,6 @@ impl Window {
compositor_api,
has_sent_idle_message: Cell::new(false),
relayout_event,
prepare_for_screenshot,
unminify_css,
userscripts_path,
player_context,