compositor: only UpdateImages that accepts SmallVec and add helpers for single image (#37730)

Before we only offered helper to add single image (no update or delete)
that got special IPC message, now we simplify this by offering all ops
helpers for dealing with single image (that happens most of the time),
that simply uses `update_images` under the hood. We also optimize for
this use case by using `SmallVec<[ImageUpdate; 1]>` to avoid alloc.

Testing: Just refactor, but code is covered by WPT tests

---------

Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>

Cargo.lock

@@ -1429,6 +1429,7 @@ dependencies = [
  "serde",
  "servo_geometry",
  "servo_malloc_size_of",
+ "smallvec",
  "strum_macros",
  "stylo",
  "stylo_traits",

components/canvas/canvas_data.rs

@@ -8,7 +8,7 @@ use std::sync::Arc;
 
 use app_units::Au;
 use canvas_traits::canvas::*;
-use compositing_traits::{CrossProcessCompositorApi, ImageUpdate, SerializableImageData};
+use compositing_traits::{CrossProcessCompositorApi, SerializableImageData};
 use euclid::default::{Box2D, Point2D, Rect, Size2D, Transform2D, Vector2D};
 use euclid::point2;
 use fonts::{
@@ -431,7 +431,7 @@ impl<'a, B: Backend> CanvasData<'a, B> {
         };
         let data =
             SerializableImageData::Raw(IpcSharedMemory::from_bytes(draw_target.bytes().as_ref()));
-        compositor_api.update_images(vec![ImageUpdate::AddImage(image_key, descriptor, data)]);
+        compositor_api.add_image(image_key, descriptor, data);
         CanvasData {
             state: backend.new_paint_state(),
             backend,
@@ -1212,11 +1212,7 @@ impl<'a, B: Backend> CanvasData<'a, B> {
         ));
 
         self.compositor_api
-            .update_images(vec![ImageUpdate::UpdateImage(
+            .update_image(self.image_key, descriptor, data);
-                self.image_key,
-                descriptor,
-                data,
-            )]);
     }
 
     // https://html.spec.whatwg.org/multipage/#dom-context-2d-putimagedata
@@ -1342,8 +1338,7 @@ impl<'a, B: Backend> CanvasData<'a, B> {
 
 impl<B: Backend> Drop for CanvasData<'_, B> {
     fn drop(&mut self) {
-        self.compositor_api
+        self.compositor_api.delete_image(self.image_key);
-            .update_images(vec![ImageUpdate::DeleteImage(self.image_key)]);
     }
 }
 

components/compositing/compositor.rs

@@ -941,12 +941,6 @@ impl IOCompositor {
                 self.global.borrow_mut().send_transaction(transaction);
             },
 
-            CompositorMsg::AddImage(key, desc, data) => {
-                let mut txn = Transaction::new();
-                txn.add_image(key, desc, data.into(), None);
-                self.global.borrow_mut().send_transaction(txn);
-            },
-
             CompositorMsg::GenerateFontKeys(
                 number_of_font_keys,
                 number_of_font_instance_keys,

components/compositing/tracing.rs

@@ -48,7 +48,6 @@ mod from_constellation {
                 Self::SendDisplayList { .. } => target!("SendDisplayList"),
                 Self::HitTest(..) => target!("HitTest"),
                 Self::GenerateImageKey(..) => target!("GenerateImageKey"),
-                Self::AddImage(..) => target!("AddImage"),
                 Self::UpdateImages(..) => target!("UpdateImages"),
                 Self::GenerateFontKeys(..) => target!("GenerateFontKeys"),
                 Self::AddFont(..) => target!("AddFont"),

components/script/dom/htmlmediaelement.rs

@@ -200,7 +200,7 @@ impl MediaFrameRenderer {
 
 impl VideoFrameRenderer for MediaFrameRenderer {
     fn render(&mut self, frame: VideoFrame) {
-        let mut updates = vec![];
+        let mut updates = smallvec::smallvec![];
 
         if let Some(old_image_key) = mem::replace(&mut self.very_old_frame, self.old_frame.take()) {
             updates.push(ImageUpdate::DeleteImage(old_image_key));

components/shared/compositing/Cargo.toml

@@ -34,6 +34,7 @@ profile_traits = { path = '../profile' }
 raw-window-handle = { version = "0.6" }
 serde = { workspace = true }
 servo_geometry = { path = "../../geometry" }
+smallvec = { workspace = true }
 strum_macros = { workspace = true }
 stylo = { workspace = true }
 stylo_traits = { workspace = true }

components/shared/compositing/lib.rs

@@ -17,6 +17,7 @@ use ipc_channel::ipc::IpcSender;
 use log::warn;
 use malloc_size_of_derive::MallocSizeOf;
 use pixels::RasterImage;
+use smallvec::SmallVec;
 use strum_macros::IntoStaticStr;
 use style_traits::CSSPixel;
 use webrender_api::DocumentId;
@@ -147,10 +148,8 @@ pub enum CompositorMsg {
     /// Create a new image key. The result will be returned via the
     /// provided channel sender.
     GenerateImageKey(IpcSender<ImageKey>),
-    /// Add an image with the given data and `ImageKey`.
-    AddImage(ImageKey, ImageDescriptor, SerializableImageData),
     /// Perform a resource update operation.
-    UpdateImages(Vec<ImageUpdate>),
+    UpdateImages(SmallVec<[ImageUpdate; 1]>),
 
     /// Generate a new batch of font keys which can be used to allocate
     /// keys asynchronously.
@@ -307,13 +306,24 @@ impl CrossProcessCompositorApi {
         descriptor: ImageDescriptor,
         data: SerializableImageData,
     ) {
-        if let Err(e) = self.0.send(CompositorMsg::AddImage(key, descriptor, data)) {
+        self.update_images([ImageUpdate::AddImage(key, descriptor, data)].into());
-            warn!("Error sending image update: {}", e);
     }
+
+    pub fn update_image(
+        &self,
+        key: ImageKey,
+        descriptor: ImageDescriptor,
+        data: SerializableImageData,
+    ) {
+        self.update_images([ImageUpdate::UpdateImage(key, descriptor, data)].into());
+    }
+
+    pub fn delete_image(&self, key: ImageKey) {
+        self.update_images([ImageUpdate::DeleteImage(key)].into());
     }
 
     /// Perform an image resource update operation.
-    pub fn update_images(&self, updates: Vec<ImageUpdate>) {
+    pub fn update_images(&self, updates: SmallVec<[ImageUpdate; 1]>) {
         if let Err(e) = self.0.send(CompositorMsg::UpdateImages(updates)) {
             warn!("error sending image updates: {}", e);
         }

components/webgl/webgl_thread.rs

@@ -23,7 +23,7 @@ use canvas_traits::webgl::{
     WebGLVersion, WebGLVertexArrayId, YAxisTreatment,
 };
 use compositing_traits::{
-    CrossProcessCompositorApi, ImageUpdate, SerializableImageData, WebrenderExternalImageRegistry,
+    CrossProcessCompositorApi, SerializableImageData, WebrenderExternalImageRegistry,
     WebrenderImageHandlerType,
 };
 use euclid::default::Size2D;
@@ -719,8 +719,7 @@ impl WebGLThread {
     fn remove_webgl_context(&mut self, context_id: WebGLContextId) {
         // Release webrender image keys.
         if let Some(info) = self.cached_context_info.remove(&context_id) {
-            self.compositor_api
+            self.compositor_api.delete_image(info.image_key);
-                .update_images(vec![ImageUpdate::DeleteImage(info.image_key)]);
         }
 
         // We need to make the context current so its resources can be disposed of.
@@ -929,11 +928,7 @@ impl WebGLThread {
         let image_data = Self::external_image_data(context_id, image_buffer_kind);
 
         self.compositor_api
-            .update_images(vec![ImageUpdate::UpdateImage(
+            .update_image(info.image_key, descriptor, image_data);
-                info.image_key,
-                descriptor,
-                image_data,
-            )]);
     }
 
     /// Helper function to create a `ImageDescriptor`.

components/webgpu/swapchain.rs

@@ -9,7 +9,7 @@ use std::sync::{Arc, Mutex};
 
 use arrayvec::ArrayVec;
 use compositing_traits::{
-    CrossProcessCompositorApi, ImageUpdate, SerializableImageData, WebrenderExternalImageApi,
+    CrossProcessCompositorApi, SerializableImageData, WebrenderExternalImageApi,
     WebrenderImageSource,
 };
 use euclid::default::Size2D;
@@ -310,7 +310,7 @@ impl ContextData {
                 warn!("Unable to send FreeBuffer({:?}) ({:?})", buffer_id, e);
             };
         }
-        compositor_api.update_images(vec![ImageUpdate::DeleteImage(self.image_key)]);
+        compositor_api.delete_image(self.image_key);
     }
 
     /// Returns true if presentation id was updated (was newer)
@@ -421,12 +421,11 @@ impl crate::WGPU {
         };
 
         if needs_image_update {
-            self.compositor_api
+            self.compositor_api.update_image(
-                .update_images(vec![ImageUpdate::UpdateImage(
                 context_data.image_key,
                 context_data.image_desc.0,
                 SerializableImageData::External(context_data.image_data),
-                )]);
+            );
         }
     }
 
@@ -574,11 +573,11 @@ fn update_wr_image(
                     return;
                 };
                 let old_presentation_buffer = swap_chain.data.replace(presentation_buffer);
-                compositor_api.update_images(vec![ImageUpdate::UpdateImage(
+                compositor_api.update_image(
                     context_data.image_key,
                     context_data.image_desc.0,
                     SerializableImageData::External(context_data.image_data),
-                )]);
+                );
                 if let Some(old_presentation_buffer) = old_presentation_buffer {
                     context_data.unmap_old_buffer(old_presentation_buffer)
                 }