/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ use std::cell::{Cell, Ref, RefCell}; use std::collections::HashMap; use std::collections::hash_map::Entry; use std::env; use std::fs::create_dir_all; use std::iter::once; use std::rc::Rc; use std::sync::Arc; use std::time::{SystemTime, UNIX_EPOCH}; use base::Epoch; use base::cross_process_instant::CrossProcessInstant; use base::generic_channel::{GenericSender, RoutedReceiver}; use base::id::{PipelineId, WebViewId}; use bitflags::bitflags; use compositing_traits::display_list::{CompositorDisplayListInfo, ScrollTree, ScrollType}; use compositing_traits::rendering_context::RenderingContext; use compositing_traits::{ CompositionPipeline, CompositorMsg, ImageUpdate, PipelineExitSource, SendableFrameTree, WebViewTrait, }; use constellation_traits::{EmbedderToConstellationMessage, PaintMetricEvent}; use crossbeam_channel::Sender; use dpi::PhysicalSize; use embedder_traits::{CompositorHitTestResult, InputEvent, ShutdownState, ViewportDetails}; use euclid::{Point2D, Rect, Scale, Size2D, Transform3D}; use ipc_channel::ipc::{self, IpcSharedMemory}; use log::{debug, info, trace, warn}; use pixels::{CorsStatus, ImageFrame, ImageMetadata, PixelFormat, RasterImage}; use profile_traits::mem::{ ProcessReports, ProfilerRegistration, Report, ReportKind, perform_memory_report, }; use profile_traits::time::{self as profile_time, ProfilerCategory}; use profile_traits::{path, time_profile}; use rustc_hash::{FxHashMap, FxHashSet}; use servo_config::{opts, pref}; use servo_geometry::DeviceIndependentPixel; use style_traits::CSSPixel; use webrender::{CaptureBits, RenderApi, Transaction}; use webrender_api::units::{ DeviceIntPoint, DeviceIntRect, DevicePixel, DevicePoint, DeviceRect, LayoutPoint, LayoutRect, LayoutSize, WorldPoint, }; use webrender_api::{ self, BuiltDisplayList, DirtyRect, DisplayListPayload, DocumentId, Epoch as WebRenderEpoch, ExternalScrollId, FontInstanceFlags, FontInstanceKey, FontInstanceOptions, FontKey, FontVariation, HitTestFlags, ImageKey, PipelineId as WebRenderPipelineId, PropertyBinding, ReferenceFrameKind, RenderReasons, SampledScrollOffset, ScrollLocation, SpaceAndClipInfo, SpatialId, SpatialTreeItemKey, TransformStyle, }; use crate::InitialCompositorState; use crate::refresh_driver::RefreshDriver; use crate::webview_manager::WebViewManager; use crate::webview_renderer::{PinchZoomResult, UnknownWebView, WebViewRenderer}; #[derive(Debug, PartialEq)] pub enum UnableToComposite { NotReadyToPaintImage(NotReadyToPaint), } #[derive(Debug, PartialEq)] pub enum NotReadyToPaint { JustNotifiedConstellation, WaitingOnConstellation, } /// Holds the state when running reftests that determines when it is /// safe to save the output image. #[derive(Clone, Copy, Debug, PartialEq)] enum ReadyState { Unknown, WaitingForConstellationReply, ReadyToSaveImage, } /// An option to control what kind of WebRender debugging is enabled while Servo is running. #[derive(Clone)] pub enum WebRenderDebugOption { Profiler, TextureCacheDebug, RenderTargetDebug, } /// Data that is shared by all WebView renderers. pub struct ServoRenderer { /// The [`RefreshDriver`] which manages the rythym of painting. refresh_driver: RefreshDriver, /// Tracks whether we are in the process of shutting down, or have shut down and should close /// the compositor. This is shared with the `Servo` instance. shutdown_state: Rc>, /// The port on which we receive messages. compositor_receiver: RoutedReceiver, /// The channel on which messages can be sent to the constellation. pub(crate) constellation_sender: Sender, /// The channel on which messages can be sent to the time profiler. time_profiler_chan: profile_time::ProfilerChan, /// The WebRender [`RenderApi`] interface used to communicate with WebRender. pub(crate) webrender_api: RenderApi, /// The active webrender document. pub(crate) webrender_document: DocumentId, /// The GL bindings for webrender webrender_gl: Rc, #[cfg(feature = "webxr")] /// Some XR devices want to run on the main thread. webxr_main_thread: webxr::MainThreadRegistry, /// The last position in the rendered view that the mouse moved over. This becomes `None` /// when the mouse leaves the rendered view. pub(crate) last_mouse_move_position: Option, /// A [`FrameRequestDelayer`] which is used to wait for canvas image updates to /// arrive before requesting a new frame, as these happen asynchronously with /// `ScriptThread` display list construction. frame_delayer: FrameDelayer, } /// NB: Never block on the constellation, because sometimes the constellation blocks on us. pub struct IOCompositor { /// Data that is shared by all WebView renderers. global: Rc>, /// Our [`WebViewRenderer`]s, one for every `WebView`. webview_renderers: WebViewManager, /// Tracks whether or not the view needs to be repainted. needs_repaint: Cell, /// Used by the logic that determines when it is safe to output an /// image for the reftest framework. ready_to_save_state: ReadyState, /// The webrender renderer. webrender: Option, /// The [`RenderingContext`] instance that webrender targets, which is the viewport. rendering_context: Rc, /// The number of frames pending to receive from WebRender. pending_frames: Cell, /// A handle to the memory profiler which will automatically unregister /// when it's dropped. _mem_profiler_registration: ProfilerRegistration, } /// Why we need to be repainted. This is used for debugging. #[derive(Clone, Copy, Default, PartialEq)] pub(crate) struct RepaintReason(u8); bitflags! { impl RepaintReason: u8 { /// We're performing the single repaint in headless mode. const ReadyForScreenshot = 1 << 0; /// We're performing a repaint to run an animation. const ChangedAnimationState = 1 << 1; /// A new WebRender frame has arrived. const NewWebRenderFrame = 1 << 2; /// The window has been resized and will need to be synchronously repainted. const Resize = 1 << 3; } } /// The paint status of a particular pipeline in the Servo renderer. This is used to trigger metrics /// in script (via the constellation) when display lists are received. /// /// See . #[derive(PartialEq)] pub(crate) enum PaintMetricState { /// The renderer is still waiting to process a display list which triggers this metric. Waiting, /// The renderer has processed the display list which will trigger this event, marked the Servo /// instance ready to paint, and is waiting for the given epoch to actually be rendered. Seen(WebRenderEpoch, bool /* first_reflow */), /// The metric has been sent to the constellation and no more work needs to be done. Sent, } pub(crate) struct PipelineDetails { /// The pipeline associated with this PipelineDetails object. pub pipeline: Option, /// The id of the parent pipeline, if any. pub parent_pipeline_id: Option, /// Whether animations are running pub animations_running: bool, /// Whether there are animation callbacks pub animation_callbacks_running: bool, /// Whether to use less resources by stopping animations. pub throttled: bool, /// The compositor-side [ScrollTree]. This is used to allow finding and scrolling /// nodes in the compositor before forwarding new offsets to WebRender. pub scroll_tree: ScrollTree, /// The paint metric status of the first paint. pub first_paint_metric: PaintMetricState, /// The paint metric status of the first contentful paint. pub first_contentful_paint_metric: PaintMetricState, /// The CSS pixel to device pixel scale of the viewport of this pipeline, including /// page zoom, but not including any pinch zoom amount. This is used to detect /// situations where the current display list is for an old scale. pub viewport_scale: Option>, /// Which parts of Servo have reported that this `Pipeline` has exited. Only when all /// have done so will it be discarded. pub exited: PipelineExitSource, } impl PipelineDetails { pub(crate) fn animation_callbacks_running(&self) -> bool { self.animation_callbacks_running } pub(crate) fn animating(&self) -> bool { !self.throttled && (self.animation_callbacks_running || self.animations_running) } } impl PipelineDetails { pub(crate) fn new() -> PipelineDetails { PipelineDetails { pipeline: None, parent_pipeline_id: None, viewport_scale: None, animations_running: false, animation_callbacks_running: false, throttled: false, scroll_tree: ScrollTree::default(), first_paint_metric: PaintMetricState::Waiting, first_contentful_paint_metric: PaintMetricState::Waiting, exited: PipelineExitSource::empty(), } } fn install_new_scroll_tree(&mut self, new_scroll_tree: ScrollTree) { let old_scroll_offsets = self.scroll_tree.scroll_offsets(); self.scroll_tree = new_scroll_tree; self.scroll_tree.set_all_scroll_offsets(&old_scroll_offsets); } } impl ServoRenderer { pub fn shutdown_state(&self) -> ShutdownState { self.shutdown_state.get() } pub(crate) fn hit_test_at_point(&self, point: DevicePoint) -> Vec { self.hit_test_at_point_with_flags(point, HitTestFlags::empty()) } // TODO: split this into first half (global) and second half (one for whole compositor, one for webview) pub(crate) fn hit_test_at_point_with_flags( &self, point: DevicePoint, flags: HitTestFlags, ) -> Vec { // DevicePoint and WorldPoint are the same for us. let world_point = WorldPoint::from_untyped(point.to_untyped()); let results = self.webrender_api.hit_test( self.webrender_document, None, /* pipeline_id */ world_point, flags, ); results .items .iter() .map(|item| { let pipeline_id = item.pipeline.into(); let external_scroll_id = ExternalScrollId(item.tag.0, item.pipeline); CompositorHitTestResult { pipeline_id, point_in_viewport: Point2D::from_untyped(item.point_in_viewport.to_untyped()), external_scroll_id, } }) .collect() } pub(crate) fn send_transaction(&mut self, transaction: Transaction) { self.webrender_api .send_transaction(self.webrender_document, transaction); } } impl IOCompositor { pub fn new(state: InitialCompositorState) -> Self { let registration = state.mem_profiler_chan.prepare_memory_reporting( "compositor".into(), state.sender.clone(), CompositorMsg::CollectMemoryReport, ); let compositor = IOCompositor { global: Rc::new(RefCell::new(ServoRenderer { refresh_driver: RefreshDriver::new( state.constellation_chan.clone(), state.event_loop_waker, ), shutdown_state: state.shutdown_state, compositor_receiver: state.receiver, constellation_sender: state.constellation_chan, time_profiler_chan: state.time_profiler_chan, webrender_api: state.webrender_api, webrender_document: state.webrender_document, webrender_gl: state.webrender_gl, #[cfg(feature = "webxr")] webxr_main_thread: state.webxr_main_thread, last_mouse_move_position: None, frame_delayer: Default::default(), })), webview_renderers: WebViewManager::default(), needs_repaint: Cell::default(), ready_to_save_state: ReadyState::Unknown, webrender: Some(state.webrender), rendering_context: state.rendering_context, pending_frames: Cell::new(0), _mem_profiler_registration: registration, }; { let gl = &compositor.global.borrow().webrender_gl; info!("Running on {}", gl.get_string(gleam::gl::RENDERER)); info!("OpenGL Version {}", gl.get_string(gleam::gl::VERSION)); } compositor.assert_gl_framebuffer_complete(); compositor } pub fn deinit(&mut self) { if let Err(err) = self.rendering_context.make_current() { warn!("Failed to make the rendering context current: {:?}", err); } if let Some(webrender) = self.webrender.take() { webrender.deinit(); } } pub fn rendering_context_size(&self) -> Size2D { self.rendering_context.size2d() } pub fn webxr_running(&self) -> bool { #[cfg(feature = "webxr")] { self.global.borrow().webxr_main_thread.running() } #[cfg(not(feature = "webxr"))] { false } } fn set_needs_repaint(&self, reason: RepaintReason) { let mut needs_repaint = self.needs_repaint.get(); needs_repaint.insert(reason); self.needs_repaint.set(needs_repaint); } pub fn needs_repaint(&self) -> bool { let repaint_reason = self.needs_repaint.get(); if repaint_reason.is_empty() { return false; } !self .global .borrow() .refresh_driver .wait_to_paint(repaint_reason) } pub fn finish_shutting_down(&mut self) { // Drain compositor port, sometimes messages contain channels that are blocking // another thread from finishing (i.e. SetFrameTree). while self .global .borrow_mut() .compositor_receiver .try_recv() .is_ok() {} // Tell the profiler, memory profiler, and scrolling timer to shut down. if let Ok((sender, receiver)) = ipc::channel() { self.global .borrow() .time_profiler_chan .send(profile_time::ProfilerMsg::Exit(sender)); let _ = receiver.recv(); } } fn handle_browser_message(&mut self, msg: CompositorMsg) { trace_msg_from_constellation!(msg, "{msg:?}"); match self.shutdown_state() { ShutdownState::NotShuttingDown => {}, ShutdownState::ShuttingDown => { self.handle_browser_message_while_shutting_down(msg); return; }, ShutdownState::FinishedShuttingDown => { // Messages to the compositor are ignored after shutdown is complete. return; }, } match msg { CompositorMsg::CollectMemoryReport(sender) => { let ops = wr_malloc_size_of::MallocSizeOfOps::new(servo_allocator::usable_size, None); let report = self.global.borrow().webrender_api.report_memory(ops); let mut reports = vec![ Report { path: path!["webrender", "fonts"], kind: ReportKind::ExplicitJemallocHeapSize, size: report.fonts, }, Report { path: path!["webrender", "images"], kind: ReportKind::ExplicitJemallocHeapSize, size: report.images, }, Report { path: path!["webrender", "display-list"], kind: ReportKind::ExplicitJemallocHeapSize, size: report.display_list, }, ]; perform_memory_report(|ops| { reports.push(Report { path: path!["compositor", "scroll-tree"], kind: ReportKind::ExplicitJemallocHeapSize, size: self.webview_renderers.scroll_trees_memory_usage(ops), }); }); sender.send(ProcessReports::new(reports)); }, CompositorMsg::ChangeRunningAnimationsState( webview_id, pipeline_id, animation_state, ) => { let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return; }; if webview_renderer .change_pipeline_running_animations_state(pipeline_id, animation_state) { self.global .borrow() .refresh_driver .notify_animation_state_changed(webview_renderer); } }, CompositorMsg::CreateOrUpdateWebView(frame_tree) => { self.set_frame_tree_for_webview(&frame_tree); }, CompositorMsg::RemoveWebView(webview_id) => { self.remove_webview(webview_id); }, CompositorMsg::TouchEventProcessed(webview_id, result) => { let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { warn!("Handling input event for unknown webview: {webview_id}"); return; }; webview_renderer.on_touch_event_processed(result); }, CompositorMsg::IsReadyToSaveImageReply(is_ready) => { assert_eq!( self.ready_to_save_state, ReadyState::WaitingForConstellationReply ); if is_ready && self.pending_frames.get() == 0 { self.ready_to_save_state = ReadyState::ReadyToSaveImage; } else { self.ready_to_save_state = ReadyState::Unknown; } self.set_needs_repaint(RepaintReason::ReadyForScreenshot); }, CompositorMsg::SetThrottled(webview_id, pipeline_id, throttled) => { let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return; }; if webview_renderer.set_throttled(pipeline_id, throttled) { self.global .borrow() .refresh_driver .notify_animation_state_changed(webview_renderer); } }, CompositorMsg::PipelineExited(webview_id, pipeline_id, pipeline_exit_source) => { debug!( "Compositor got pipeline exited: {:?} {:?}", webview_id, pipeline_id ); if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.pipeline_exited(pipeline_id, pipeline_exit_source); } }, CompositorMsg::NewWebRenderFrameReady(_document_id, recomposite_needed) => { self.handle_new_webrender_frame_ready(recomposite_needed); }, CompositorMsg::LoadComplete(_) => { if opts::get().wait_for_stable_image { self.set_needs_repaint(RepaintReason::ReadyForScreenshot); } }, CompositorMsg::SendInitialTransaction(pipeline) => { let mut txn = Transaction::new(); txn.set_display_list(WebRenderEpoch(0), (pipeline, Default::default())); self.generate_frame(&mut txn, RenderReasons::SCENE); self.global.borrow_mut().send_transaction(txn); }, CompositorMsg::SendScrollNode(webview_id, pipeline_id, offset, external_scroll_id) => { let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return; }; let pipeline_id = pipeline_id.into(); let Some(pipeline_details) = webview_renderer.pipelines.get_mut(&pipeline_id) else { return; }; let Some(offset) = pipeline_details .scroll_tree .set_scroll_offset_for_node_with_external_scroll_id( external_scroll_id, offset, ScrollType::Script, ) else { // The renderer should be fully up-to-date with script at this point and script // should never try to scroll to an invalid location. warn!("Could not scroll node with id: {external_scroll_id:?}"); return; }; let mut txn = Transaction::new(); txn.set_scroll_offsets( external_scroll_id, vec![SampledScrollOffset { offset, generation: 0, }], ); self.generate_frame(&mut txn, RenderReasons::APZ); self.global.borrow_mut().send_transaction(txn); }, CompositorMsg::SendDisplayList { webview_id, display_list_descriptor, display_list_receiver, } => { // This must match the order from the sender, currently in `shared/script/lib.rs`. let display_list_info = match display_list_receiver.recv() { Ok(display_list_info) => display_list_info, Err(error) => { return warn!("Could not receive display list info: {error}"); }, }; let display_list_info: CompositorDisplayListInfo = match bincode::deserialize(&display_list_info) { Ok(display_list_info) => display_list_info, Err(error) => { return warn!("Could not deserialize display list info: {error}"); }, }; let items_data = match display_list_receiver.recv() { Ok(display_list_data) => display_list_data, Err(error) => { return warn!( "Could not receive WebRender display list items data: {error}" ); }, }; let cache_data = match display_list_receiver.recv() { Ok(display_list_data) => display_list_data, Err(error) => { return warn!( "Could not receive WebRender display list cache data: {error}" ); }, }; let spatial_tree = match display_list_receiver.recv() { Ok(display_list_data) => display_list_data, Err(error) => { return warn!( "Could not receive WebRender display list spatial tree: {error}." ); }, }; let built_display_list = BuiltDisplayList::from_data( DisplayListPayload { items_data, cache_data, spatial_tree, }, display_list_descriptor, ); #[cfg(feature = "tracing")] let _span = tracing::trace_span!( "ScriptToCompositorMsg::BuiltDisplayList", servo_profiling = true, ) .entered(); let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return warn!("Could not find WebView for incoming display list"); }; let old_scale = webview_renderer.device_pixels_per_page_pixel(); let pipeline_id = display_list_info.pipeline_id; let details = webview_renderer.ensure_pipeline_details(pipeline_id.into()); details.install_new_scroll_tree(display_list_info.scroll_tree); details.viewport_scale = Some(display_list_info.viewport_details.hidpi_scale_factor); let epoch = display_list_info.epoch; let first_reflow = display_list_info.first_reflow; if details.first_paint_metric == PaintMetricState::Waiting { details.first_paint_metric = PaintMetricState::Seen(epoch, first_reflow); } if details.first_contentful_paint_metric == PaintMetricState::Waiting && display_list_info.is_contentful { details.first_contentful_paint_metric = PaintMetricState::Seen(epoch, first_reflow); } let mut transaction = Transaction::new(); let is_root_pipeline = Some(pipeline_id.into()) == webview_renderer.root_pipeline_id; if is_root_pipeline && old_scale != webview_renderer.device_pixels_per_page_pixel() { self.send_root_pipeline_display_list_in_transaction(&mut transaction); } transaction .set_display_list(display_list_info.epoch, (pipeline_id, built_display_list)); self.update_transaction_with_all_scroll_offsets(&mut transaction); self.global.borrow_mut().send_transaction(transaction); }, CompositorMsg::GenerateFrame => { let mut global = self.global.borrow_mut(); global.frame_delayer.set_pending_frame(true); if global.frame_delayer.needs_new_frame() { let mut transaction = Transaction::new(); self.generate_frame(&mut transaction, RenderReasons::SCENE); global.send_transaction(transaction); let waiting_pipelines = global.frame_delayer.take_waiting_pipelines(); let _ = global.constellation_sender.send( EmbedderToConstellationMessage::NoLongerWaitingOnAsynchronousImageUpdates( waiting_pipelines, ), ); global.frame_delayer.set_pending_frame(false); } }, CompositorMsg::GenerateImageKey(sender) => { let _ = sender.send(self.global.borrow().webrender_api.generate_image_key()); }, CompositorMsg::GenerateImageKeysForPipeline(pipeline_id) => { let image_keys = (0..pref!(image_key_batch_size)) .map(|_| self.global.borrow().webrender_api.generate_image_key()) .collect(); if let Err(error) = self.global.borrow().constellation_sender.send( EmbedderToConstellationMessage::SendImageKeysForPipeline( pipeline_id, image_keys, ), ) { warn!("Sending Image Keys to Constellation failed with({error:?})."); } }, CompositorMsg::UpdateImages(updates) => { let mut global = self.global.borrow_mut(); let mut txn = Transaction::new(); for update in updates { match update { ImageUpdate::AddImage(key, desc, data) => { txn.add_image(key, desc, data.into(), None) }, ImageUpdate::DeleteImage(key) => { txn.delete_image(key); global.frame_delayer.delete_image(key); }, ImageUpdate::UpdateImage(key, desc, data, epoch) => { if let Some(epoch) = epoch { global.frame_delayer.update_image(key, epoch); } txn.update_image(key, desc, data.into(), &DirtyRect::All) }, } } if global.frame_delayer.needs_new_frame() { global.frame_delayer.set_pending_frame(false); self.generate_frame(&mut txn, RenderReasons::SCENE); let waiting_pipelines = global.frame_delayer.take_waiting_pipelines(); let _ = global.constellation_sender.send( EmbedderToConstellationMessage::NoLongerWaitingOnAsynchronousImageUpdates( waiting_pipelines, ), ); } global.send_transaction(txn); }, CompositorMsg::DelayNewFrameForCanvas(pipeline_id, canvas_epoch, image_keys) => self .global .borrow_mut() .frame_delayer .add_delay(pipeline_id, canvas_epoch, image_keys), CompositorMsg::AddFont(font_key, data, index) => { self.add_font(font_key, index, data); }, CompositorMsg::AddSystemFont(font_key, native_handle) => { let mut transaction = Transaction::new(); transaction.add_native_font(font_key, native_handle); self.global.borrow_mut().send_transaction(transaction); }, CompositorMsg::AddFontInstance( font_instance_key, font_key, size, flags, variations, ) => { self.add_font_instance(font_instance_key, font_key, size, flags, variations); }, CompositorMsg::RemoveFonts(keys, instance_keys) => { let mut transaction = Transaction::new(); for instance in instance_keys.into_iter() { transaction.delete_font_instance(instance); } for key in keys.into_iter() { transaction.delete_font(key); } self.global.borrow_mut().send_transaction(transaction); }, CompositorMsg::GenerateFontKeys( number_of_font_keys, number_of_font_instance_keys, result_sender, ) => { self.handle_generate_font_keys( number_of_font_keys, number_of_font_instance_keys, result_sender, ); }, CompositorMsg::Viewport(webview_id, viewport_description) => { if let Some(webview) = self.webview_renderers.get_mut(webview_id) { webview.set_viewport_description(viewport_description); } }, } } /// Handle messages sent to the compositor during the shutdown process. In general, /// the things the compositor can do in this state are limited. It's very important to /// answer any synchronous messages though as other threads might be waiting on the /// results to finish their own shut down process. We try to do as little as possible /// during this time. /// /// When that involves generating WebRender ids, our approach here is to simply /// generate them, but assume they will never be used, since once shutting down the /// compositor no longer does any WebRender frame generation. fn handle_browser_message_while_shutting_down(&mut self, msg: CompositorMsg) { match msg { CompositorMsg::PipelineExited(webview_id, pipeline_id, pipeline_exit_source) => { debug!( "Compositor got pipeline exited: {:?} {:?}", webview_id, pipeline_id ); if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.pipeline_exited(pipeline_id, pipeline_exit_source); } }, CompositorMsg::GenerateImageKey(sender) => { let _ = sender.send(self.global.borrow().webrender_api.generate_image_key()); }, CompositorMsg::GenerateFontKeys( number_of_font_keys, number_of_font_instance_keys, result_sender, ) => { self.handle_generate_font_keys( number_of_font_keys, number_of_font_instance_keys, result_sender, ); }, CompositorMsg::NewWebRenderFrameReady(..) => { // Subtract from the number of pending frames, but do not do any compositing. self.pending_frames.set(self.pending_frames.get() - 1); }, _ => { debug!("Ignoring message ({:?} while shutting down", msg); }, } } /// Generate the font keys and send them to the `result_sender`. fn handle_generate_font_keys( &self, number_of_font_keys: usize, number_of_font_instance_keys: usize, result_sender: GenericSender<(Vec, Vec)>, ) { let font_keys = (0..number_of_font_keys) .map(|_| self.global.borrow().webrender_api.generate_font_key()) .collect(); let font_instance_keys = (0..number_of_font_instance_keys) .map(|_| { self.global .borrow() .webrender_api .generate_font_instance_key() }) .collect(); let _ = result_sender.send((font_keys, font_instance_keys)); } /// Queue a new frame in the transaction and increase the pending frames count. pub(crate) fn generate_frame(&self, transaction: &mut Transaction, reason: RenderReasons) { self.pending_frames.set(self.pending_frames.get() + 1); transaction.generate_frame(0, true /* present */, reason); } /// Set the root pipeline for our WebRender scene to a display list that consists of an iframe /// for each visible top-level browsing context, applying a transformation on the root for /// pinch zoom, page zoom, and HiDPI scaling. fn send_root_pipeline_display_list(&mut self) { let mut transaction = Transaction::new(); self.send_root_pipeline_display_list_in_transaction(&mut transaction); self.generate_frame(&mut transaction, RenderReasons::SCENE); self.global.borrow_mut().send_transaction(transaction); } /// Set the root pipeline for our WebRender scene to a display list that consists of an iframe /// for each visible top-level browsing context, applying a transformation on the root for /// pinch zoom, page zoom, and HiDPI scaling. pub(crate) fn send_root_pipeline_display_list_in_transaction( &self, transaction: &mut Transaction, ) { // Every display list needs a pipeline, but we'd like to choose one that is unlikely // to conflict with our content pipelines, which start at (1, 1). (0, 0) is WebRender's // dummy pipeline, so we choose (0, 1). let root_pipeline = WebRenderPipelineId(0, 1); transaction.set_root_pipeline(root_pipeline); let mut builder = webrender_api::DisplayListBuilder::new(root_pipeline); builder.begin(); let root_reference_frame = SpatialId::root_reference_frame(root_pipeline); let viewport_size = self.rendering_context.size2d().to_f32().to_untyped(); let viewport_rect = LayoutRect::from_origin_and_size( LayoutPoint::zero(), LayoutSize::from_untyped(viewport_size), ); let root_clip_id = builder.define_clip_rect(root_reference_frame, viewport_rect); let clip_chain_id = builder.define_clip_chain(None, [root_clip_id]); for (_, webview_renderer) in self.webview_renderers.painting_order() { let Some(pipeline_id) = webview_renderer.root_pipeline_id else { continue; }; let device_pixels_per_page_pixel = webview_renderer.device_pixels_per_page_pixel().0; let webview_reference_frame = builder.push_reference_frame( LayoutPoint::zero(), root_reference_frame, TransformStyle::Flat, PropertyBinding::Value(Transform3D::scale( device_pixels_per_page_pixel, device_pixels_per_page_pixel, 1., )), ReferenceFrameKind::Transform { is_2d_scale_translation: true, should_snap: true, paired_with_perspective: false, }, SpatialTreeItemKey::new(0, 0), ); let scaled_webview_rect = webview_renderer.rect / device_pixels_per_page_pixel; builder.push_iframe( LayoutRect::from_untyped(&scaled_webview_rect.to_untyped()), LayoutRect::from_untyped(&scaled_webview_rect.to_untyped()), &SpaceAndClipInfo { spatial_id: webview_reference_frame, clip_chain_id, }, pipeline_id.into(), true, ); } let built_display_list = builder.end(); // NB: We are always passing 0 as the epoch here, but this doesn't seem to // be an issue. WebRender will still update the scene and generate a new // frame even though the epoch hasn't changed. transaction.set_display_list(WebRenderEpoch(0), built_display_list); self.update_transaction_with_all_scroll_offsets(transaction); } /// Update the given transaction with the scroll offsets of all active scroll nodes in /// the WebRender scene. This is necessary because WebRender does not preserve scroll /// offsets between scroll tree modifications. If a display list could potentially /// modify a scroll tree branch, WebRender needs to have scroll offsets for that /// branch. /// /// TODO(mrobinson): Could we only send offsets for the branch being modified /// and not the entire scene? fn update_transaction_with_all_scroll_offsets(&self, transaction: &mut Transaction) { for webview_renderer in self.webview_renderers.iter() { for details in webview_renderer.pipelines.values() { for node in details.scroll_tree.nodes.iter() { let (Some(offset), Some(external_id)) = (node.offset(), node.external_id()) else { continue; }; transaction.set_scroll_offsets( external_id, vec![SampledScrollOffset { offset, generation: 0, }], ); } } } } pub fn add_webview( &mut self, webview: Box, viewport_details: ViewportDetails, ) { self.webview_renderers .entry(webview.id()) .or_insert(WebViewRenderer::new( self.global.clone(), webview, viewport_details, )); } fn set_frame_tree_for_webview(&mut self, frame_tree: &SendableFrameTree) { debug!("{}: Setting frame tree for webview", frame_tree.pipeline.id); let webview_id = frame_tree.pipeline.webview_id; let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { warn!( "Attempted to set frame tree on unknown WebView (perhaps closed?): {webview_id:?}" ); return; }; webview_renderer.set_frame_tree(frame_tree); self.send_root_pipeline_display_list(); } fn remove_webview(&mut self, webview_id: WebViewId) { debug!("{}: Removing", webview_id); if self.webview_renderers.remove(webview_id).is_err() { warn!("{webview_id}: Removing unknown webview"); return; }; self.send_root_pipeline_display_list(); } pub fn show_webview( &mut self, webview_id: WebViewId, hide_others: bool, ) -> Result<(), UnknownWebView> { debug!("{webview_id}: Showing webview; hide_others={hide_others}"); let painting_order_changed = if hide_others { let result = self .webview_renderers .painting_order() .map(|(&id, _)| id) .ne(once(webview_id)); self.webview_renderers.hide_all(); self.webview_renderers.show(webview_id)?; result } else { self.webview_renderers.show(webview_id)? }; if painting_order_changed { self.send_root_pipeline_display_list(); } Ok(()) } pub fn hide_webview(&mut self, webview_id: WebViewId) -> Result<(), UnknownWebView> { debug!("{webview_id}: Hiding webview"); if self.webview_renderers.hide(webview_id)? { self.send_root_pipeline_display_list(); } Ok(()) } pub fn raise_webview_to_top( &mut self, webview_id: WebViewId, hide_others: bool, ) -> Result<(), UnknownWebView> { debug!("{webview_id}: Raising webview to top; hide_others={hide_others}"); let painting_order_changed = if hide_others { let result = self .webview_renderers .painting_order() .map(|(&id, _)| id) .ne(once(webview_id)); self.webview_renderers.hide_all(); self.webview_renderers.raise_to_top(webview_id)?; result } else { self.webview_renderers.raise_to_top(webview_id)? }; if painting_order_changed { self.send_root_pipeline_display_list(); } Ok(()) } pub fn move_resize_webview(&mut self, webview_id: WebViewId, rect: DeviceRect) { if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown { return; } let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return; }; if !webview_renderer.set_rect(rect) { return; } self.send_root_pipeline_display_list(); self.set_needs_repaint(RepaintReason::Resize); } pub fn set_hidpi_scale_factor( &mut self, webview_id: WebViewId, new_scale_factor: Scale, ) { if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown { return; } let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else { return; }; if !webview_renderer.set_hidpi_scale_factor(new_scale_factor) { return; } self.send_root_pipeline_display_list(); self.set_needs_repaint(RepaintReason::Resize); } pub fn resize_rendering_context(&mut self, new_size: PhysicalSize) { if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown { return; } if self.rendering_context.size() == new_size { return; } self.rendering_context.resize(new_size); let mut transaction = Transaction::new(); let output_region = DeviceIntRect::new( Point2D::zero(), Point2D::new(new_size.width as i32, new_size.height as i32), ); transaction.set_document_view(output_region); self.global.borrow_mut().send_transaction(transaction); self.send_root_pipeline_display_list(); self.set_needs_repaint(RepaintReason::Resize); } pub fn on_zoom_reset_window_event(&mut self, webview_id: WebViewId) { if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown { return; } if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.set_page_zoom(Scale::new(1.0)); } } pub fn on_zoom_window_event(&mut self, webview_id: WebViewId, magnification: f32) { if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown { return; } if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { let current_page_zoom = webview_renderer.page_zoom(); webview_renderer.set_page_zoom(current_page_zoom * Scale::new(magnification)); } } /// Returns true if any animation callbacks (ie `requestAnimationFrame`) are waiting for a response. fn animation_callbacks_running(&self) -> bool { self.webview_renderers .iter() .any(WebViewRenderer::animation_callbacks_running) } /// Query the constellation to see if the current compositor /// output matches the current frame tree output, and if the /// associated script threads are idle. fn is_ready_to_paint_image_output(&mut self) -> Result<(), NotReadyToPaint> { match self.ready_to_save_state { ReadyState::Unknown => { // Unsure if the output image is stable. // Collect the currently painted epoch of each pipeline that is // complete (i.e. has *all* layers painted to the requested epoch). // This gets sent to the constellation for comparison with the current // frame tree. let mut pipeline_epochs = FxHashMap::default(); for id in self .webview_renderers .iter() .flat_map(WebViewRenderer::pipeline_ids) { if let Some(WebRenderEpoch(epoch)) = self .webrender .as_ref() .and_then(|wr| wr.current_epoch(self.webrender_document(), id.into())) { let epoch = Epoch(epoch); pipeline_epochs.insert(*id, epoch); } } // Pass the pipeline/epoch states to the constellation and check // if it's safe to output the image. let msg = EmbedderToConstellationMessage::IsReadyToSaveImage(pipeline_epochs); if let Err(e) = self.global.borrow().constellation_sender.send(msg) { warn!("Sending ready to save to constellation failed ({:?}).", e); } self.ready_to_save_state = ReadyState::WaitingForConstellationReply; Err(NotReadyToPaint::JustNotifiedConstellation) }, ReadyState::WaitingForConstellationReply => { // If waiting on a reply from the constellation to the last // query if the image is stable, then assume not ready yet. Err(NotReadyToPaint::WaitingOnConstellation) }, ReadyState::ReadyToSaveImage => { // Constellation has replied at some point in the past // that the current output image is stable and ready // for saving. // Reset the flag so that we check again in the future // TODO: only reset this if we load a new document? self.ready_to_save_state = ReadyState::Unknown; Ok(()) }, } } /// Render the WebRender scene to the active `RenderingContext`. If successful, trigger /// the next round of animations. Return false if unable to render. pub fn render(&mut self) -> bool { self.global .borrow() .refresh_driver .notify_will_paint(self.webview_renderers.iter()); if let Err(error) = self.render_inner() { warn!("Unable to render: {error:?}"); return false; } // We've painted the default target, which means that from the embedder's perspective, // the scene no longer needs to be repainted. self.needs_repaint.set(RepaintReason::empty()); true } /// Render the WebRender scene to the shared memory, without updating other state of this /// [`IOCompositor`]. If succesful return the output image in shared memory. pub fn render_to_shared_memory( &mut self, webview_id: WebViewId, page_rect: Option>, ) -> Result, UnableToComposite> { self.render_inner()?; let size = self.rendering_context.size2d().to_i32(); let rect = if let Some(rect) = page_rect { let scale = self .webview_renderers .get(webview_id) .map(WebViewRenderer::device_pixels_per_page_pixel) .unwrap_or_else(|| Scale::new(1.0)); let rect = scale.transform_rect(&rect); let x = rect.origin.x as i32; // We need to convert to the bottom-left origin coordinate // system used by OpenGL let y = (size.height as f32 - rect.origin.y - rect.size.height) as i32; let w = rect.size.width as i32; let h = rect.size.height as i32; DeviceIntRect::from_origin_and_size(Point2D::new(x, y), Size2D::new(w, h)) } else { DeviceIntRect::from_origin_and_size(Point2D::origin(), size) }; Ok(self .rendering_context .read_to_image(rect) .map(|image| RasterImage { metadata: ImageMetadata { width: image.width(), height: image.height(), }, format: PixelFormat::RGBA8, frames: vec![ImageFrame { delay: None, byte_range: 0..image.len(), width: image.width(), height: image.height(), }], bytes: ipc::IpcSharedMemory::from_bytes(&image), id: None, cors_status: CorsStatus::Safe, })) } #[servo_tracing::instrument(skip_all)] fn render_inner(&mut self) -> Result<(), UnableToComposite> { if let Err(err) = self.rendering_context.make_current() { warn!("Failed to make the rendering context current: {:?}", err); } self.assert_no_gl_error(); if let Some(webrender) = self.webrender.as_mut() { webrender.update(); } if opts::get().wait_for_stable_image { if let Err(result) = self.is_ready_to_paint_image_output() { return Err(UnableToComposite::NotReadyToPaintImage(result)); } } self.rendering_context.prepare_for_rendering(); let time_profiler_chan = self.global.borrow().time_profiler_chan.clone(); time_profile!( ProfilerCategory::Compositing, None, time_profiler_chan, || { trace!("Compositing"); // Paint the scene. // TODO(gw): Take notice of any errors the renderer returns! self.clear_background(); if let Some(webrender) = self.webrender.as_mut() { let size = self.rendering_context.size2d().to_i32(); webrender.render(size, 0 /* buffer_age */).ok(); } }, ); self.send_pending_paint_metrics_messages_after_composite(); Ok(()) } /// Send all pending paint metrics messages after a composite operation, which may advance /// the epoch for pipelines in the WebRender scene. /// /// If there are pending paint metrics, we check if any of the painted epochs is one /// of the ones that the paint metrics recorder is expecting. In that case, we get the /// current time, inform the constellation about it and remove the pending metric from /// the list. fn send_pending_paint_metrics_messages_after_composite(&mut self) { let paint_time = CrossProcessInstant::now(); let document_id = self.webrender_document(); for webview_renderer in self.webview_renderers.iter_mut() { for (pipeline_id, pipeline) in webview_renderer.pipelines.iter_mut() { let Some(current_epoch) = self .webrender .as_ref() .and_then(|wr| wr.current_epoch(document_id, pipeline_id.into())) else { continue; }; match pipeline.first_paint_metric { // We need to check whether the current epoch is later, because // CrossProcessCompositorMessage::SendInitialTransaction sends an // empty display list to WebRender which can happen before we receive // the first "real" display list. PaintMetricState::Seen(epoch, first_reflow) if epoch <= current_epoch => { assert!(epoch <= current_epoch); if let Err(error) = self.global.borrow().constellation_sender.send( EmbedderToConstellationMessage::PaintMetric( *pipeline_id, PaintMetricEvent::FirstPaint(paint_time, first_reflow), ), ) { warn!( "Sending paint metric event to constellation failed ({error:?})." ); } pipeline.first_paint_metric = PaintMetricState::Sent; }, _ => {}, } match pipeline.first_contentful_paint_metric { PaintMetricState::Seen(epoch, first_reflow) if epoch <= current_epoch => { if let Err(error) = self.global.borrow().constellation_sender.send( EmbedderToConstellationMessage::PaintMetric( *pipeline_id, PaintMetricEvent::FirstContentfulPaint(paint_time, first_reflow), ), ) { warn!( "Sending paint metric event to constellation failed ({error:?})." ); } pipeline.first_contentful_paint_metric = PaintMetricState::Sent; }, _ => {}, } } } } fn clear_background(&self) { let gl = &self.global.borrow().webrender_gl; self.assert_gl_framebuffer_complete(); // Always clear the entire RenderingContext, regardless of how many WebViews there are // or where they are positioned. This is so WebView actually clears even before the // first WebView is ready. let color = servo_config::pref!(shell_background_color_rgba); gl.clear_color( color[0] as f32, color[1] as f32, color[2] as f32, color[3] as f32, ); gl.clear(gleam::gl::COLOR_BUFFER_BIT); } #[track_caller] fn assert_no_gl_error(&self) { debug_assert_eq!( self.global.borrow().webrender_gl.get_error(), gleam::gl::NO_ERROR ); } #[track_caller] fn assert_gl_framebuffer_complete(&self) { debug_assert_eq!( ( self.global.borrow().webrender_gl.get_error(), self.global .borrow() .webrender_gl .check_frame_buffer_status(gleam::gl::FRAMEBUFFER) ), (gleam::gl::NO_ERROR, gleam::gl::FRAMEBUFFER_COMPLETE) ); } /// Get the message receiver for this [`IOCompositor`]. pub fn receiver(&self) -> Ref<'_, RoutedReceiver> { Ref::map(self.global.borrow(), |global| &global.compositor_receiver) } #[servo_tracing::instrument(skip_all)] pub fn handle_messages(&mut self, mut messages: Vec) { // Check for new messages coming from the other threads in the system. let mut found_recomposite_msg = false; messages.retain(|message| { match message { CompositorMsg::NewWebRenderFrameReady(..) if found_recomposite_msg => { // Only take one of duplicate NewWebRendeFrameReady messages, but do subtract // one frame from the pending frames. self.pending_frames.set(self.pending_frames.get() - 1); false }, CompositorMsg::NewWebRenderFrameReady(..) => { found_recomposite_msg = true; true }, _ => true, } }); for message in messages { self.handle_browser_message(message); if self.global.borrow().shutdown_state() == ShutdownState::FinishedShuttingDown { return; } } } #[servo_tracing::instrument(skip_all)] pub fn perform_updates(&mut self) -> bool { if self.global.borrow().shutdown_state() == ShutdownState::FinishedShuttingDown { return false; } #[cfg(feature = "webxr")] // Run the WebXR main thread self.global.borrow_mut().webxr_main_thread.run_one_frame(); // The WebXR thread may make a different context current if let Err(err) = self.rendering_context.make_current() { warn!("Failed to make the rendering context current: {:?}", err); } let mut need_zoom = false; let scroll_offset_updates: Vec<_> = self .webview_renderers .iter_mut() .filter_map(|webview_renderer| { let (zoom, scroll_result) = webview_renderer.process_pending_scroll_and_pinch_zoom_events(); need_zoom = need_zoom || (zoom == PinchZoomResult::DidPinchZoom); scroll_result }) .collect(); if need_zoom || !scroll_offset_updates.is_empty() { let mut transaction = Transaction::new(); if need_zoom { self.send_root_pipeline_display_list_in_transaction(&mut transaction); } for update in scroll_offset_updates { transaction.set_scroll_offsets( update.external_scroll_id, vec![SampledScrollOffset { offset: update.offset, generation: 0, }], ); } self.generate_frame(&mut transaction, RenderReasons::APZ); self.global.borrow_mut().send_transaction(transaction); } self.global.borrow().shutdown_state() != ShutdownState::FinishedShuttingDown } pub fn toggle_webrender_debug(&mut self, option: WebRenderDebugOption) { let Some(webrender) = self.webrender.as_mut() else { return; }; let mut flags = webrender.get_debug_flags(); let flag = match option { WebRenderDebugOption::Profiler => { webrender::DebugFlags::PROFILER_DBG | webrender::DebugFlags::GPU_TIME_QUERIES | webrender::DebugFlags::GPU_SAMPLE_QUERIES }, WebRenderDebugOption::TextureCacheDebug => webrender::DebugFlags::TEXTURE_CACHE_DBG, WebRenderDebugOption::RenderTargetDebug => webrender::DebugFlags::RENDER_TARGET_DBG, }; flags.toggle(flag); webrender.set_debug_flags(flags); let mut txn = Transaction::new(); self.generate_frame(&mut txn, RenderReasons::TESTING); self.global.borrow_mut().send_transaction(txn); } pub fn capture_webrender(&mut self) { let capture_id = SystemTime::now() .duration_since(UNIX_EPOCH) .unwrap_or_default() .as_secs() .to_string(); let available_path = [env::current_dir(), Ok(env::temp_dir())] .iter() .filter_map(|val| { val.as_ref() .map(|dir| dir.join("webrender-captures").join(&capture_id)) .ok() }) .find(|val| create_dir_all(val).is_ok()); let Some(capture_path) = available_path else { eprintln!("Couldn't create a path for WebRender captures."); return; }; println!("Saving WebRender capture to {capture_path:?}"); self.global .borrow() .webrender_api .save_capture(capture_path.clone(), CaptureBits::all()); } fn add_font_instance( &mut self, instance_key: FontInstanceKey, font_key: FontKey, size: f32, flags: FontInstanceFlags, variations: Vec, ) { let variations = if pref!(layout_variable_fonts_enabled) { variations } else { vec![] }; let mut transaction = Transaction::new(); let font_instance_options = FontInstanceOptions { flags, ..Default::default() }; transaction.add_font_instance( instance_key, font_key, size, Some(font_instance_options), None, variations, ); self.global.borrow_mut().send_transaction(transaction); } fn add_font(&mut self, font_key: FontKey, index: u32, data: Arc) { let mut transaction = Transaction::new(); transaction.add_raw_font(font_key, (**data).into(), index); self.global.borrow_mut().send_transaction(transaction); } pub fn notify_input_event(&mut self, webview_id: WebViewId, event: InputEvent) { if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.notify_input_event(event); } } pub fn notify_scroll_event( &mut self, webview_id: WebViewId, scroll_location: ScrollLocation, cursor: DeviceIntPoint, ) { if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.notify_scroll_event(scroll_location, cursor); } } pub fn on_vsync(&mut self, webview_id: WebViewId) { if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.on_vsync(); } } pub fn set_pinch_zoom(&mut self, webview_id: WebViewId, magnification: f32) { if let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) { webview_renderer.set_pinch_zoom(magnification); } } fn webrender_document(&self) -> DocumentId { self.global.borrow().webrender_document } fn shutdown_state(&self) -> ShutdownState { self.global.borrow().shutdown_state() } fn refresh_cursor(&self) { let global = self.global.borrow(); let Some(last_mouse_move_position) = global.last_mouse_move_position else { return; }; let Some(hit_test_result) = global .hit_test_at_point(last_mouse_move_position) .first() .cloned() else { return; }; if let Err(error) = global .constellation_sender .send(EmbedderToConstellationMessage::RefreshCursor( hit_test_result.pipeline_id, )) { warn!("Sending event to constellation failed ({:?}).", error); } } fn handle_new_webrender_frame_ready(&mut self, recomposite_needed: bool) { self.pending_frames.set(self.pending_frames.get() - 1); if recomposite_needed { self.refresh_cursor(); } if recomposite_needed || self.animation_callbacks_running() { self.set_needs_repaint(RepaintReason::NewWebRenderFrame); } } } /// A struct that is reponsible for delaying frame requests until all new canvas images /// for a particular "update the rendering" call in the `ScriptThread` have been /// sent to WebRender. /// /// These images may be updated in WebRender asynchronously in the canvas task. A frame /// is then requested if: /// /// - The renderer has received a GenerateFrame message from a `ScriptThread`. /// - All pending image updates have finished and have been noted in the [`FrameDelayer`]. #[derive(Default)] struct FrameDelayer { /// The latest [`Epoch`] of canvas images that have been sent to WebRender. Note /// that this only records the `Epoch`s for canvases and only ones that are involved /// in "update the rendering". image_epochs: HashMap, /// A map of all pending canvas images pending_canvas_images: HashMap, /// Whether or not we have a pending frame. pending_frame: bool, /// A list of pipelines that should be notified when we are no longer waiting for /// canvas images. waiting_pipelines: FxHashSet, } impl FrameDelayer { fn delete_image(&mut self, image_key: ImageKey) { self.image_epochs.remove(&image_key); self.pending_canvas_images.remove(&image_key); } fn update_image(&mut self, image_key: ImageKey, epoch: Epoch) { self.image_epochs.insert(image_key, epoch); let Entry::Occupied(entry) = self.pending_canvas_images.entry(image_key) else { return; }; if *entry.get() <= epoch { entry.remove(); } } fn add_delay( &mut self, pipeline_id: PipelineId, canvas_epoch: Epoch, image_keys: Vec, ) { for image_key in image_keys.into_iter() { // If we've already seen the necessary epoch for this image, do not // start waiting for it. if self .image_epochs .get(&image_key) .is_some_and(|epoch_seen| *epoch_seen >= canvas_epoch) { continue; } self.pending_canvas_images.insert(image_key, canvas_epoch); } self.waiting_pipelines.insert(pipeline_id); } fn needs_new_frame(&self) -> bool { self.pending_frame && self.pending_canvas_images.is_empty() } fn set_pending_frame(&mut self, value: bool) { self.pending_frame = value; } fn take_waiting_pipelines(&mut self) -> Vec { self.waiting_pipelines.drain().collect() } }