Implement mapReadAsync function of GPUBuffer

Implemented the `mapReadAsync` and fixed the `unmap` functions of `GPUBuffer`.
Added `mapped` internal slot for tracking the ArrayBuffer/Promise.
Added more states to the `GPUBufferState` enum.

1 files changed, 27 insertions, 36 deletions

diff --git a/components/script/dom/gpudevice.rs b/components/script/dom/gpudevice.rs
index 1d17961f87c..40e97d34d28 100644
--- a/components/script/dom/gpudevice.rs
+++ b/components/script/dom/gpudevice.rs
@@ -46,7 +46,7 @@ use webgpu::wgpu::binding_model::{
     ShaderStage,
 };
 use webgpu::wgpu::resource::{BufferDescriptor, BufferUsage};
-use webgpu::{WebGPU, WebGPUBuffer, WebGPUDevice, WebGPUQueue, WebGPURequest};
+use webgpu::{WebGPU, WebGPUDevice, WebGPUQueue, WebGPURequest};
 
 #[dom_struct]
 pub struct GPUDevice {
@@ -106,38 +106,6 @@ impl GPUDevice {
 }
 
 impl GPUDevice {
-    unsafe fn resolve_create_buffer_mapped(
-        &self,
-        cx: SafeJSContext,
-        gpu_buffer: WebGPUBuffer,
-        array_buffer: Vec<u8>,
-        descriptor: BufferDescriptor,
-        valid: bool,
-    ) -> Vec<JSVal> {
-        rooted!(in(*cx) let mut js_array_buffer = ptr::null_mut::<JSObject>());
-        let mut out = Vec::new();
-        assert!(ArrayBuffer::create(
-            *cx,
-            CreateWith::Slice(array_buffer.as_slice()),
-            js_array_buffer.handle_mut(),
-        )
-        .is_ok());
-
-        let buff = GPUBuffer::new(
-            &self.global(),
-            self.channel.clone(),
-            gpu_buffer,
-            self.device,
-            GPUBufferState::Mapped,
-            descriptor.size,
-            descriptor.usage.bits(),
-            valid,
-        );
-        out.push(ObjectValue(buff.reflector().get_jsobject().get()));
-        out.push(ObjectValue(js_array_buffer.get()));
-        out
-    }
-
     fn validate_buffer_descriptor(
         &self,
         descriptor: &GPUBufferDescriptor,
@@ -223,6 +191,7 @@ impl GPUDeviceMethods for GPUDevice {
             descriptor.size,
             descriptor.usage,
             valid,
+            RootedTraceableBox::new(Heap::default()),
         )
     }
 
@@ -245,11 +214,33 @@ impl GPUDeviceMethods for GPUDevice {
             ))
             .expect("Failed to create WebGPU buffer");
 
-        let (buffer, array_buffer) = receiver.recv().unwrap();
-
+        rooted!(in(*cx) let mut js_array_buffer = ptr::null_mut::<JSObject>());
         unsafe {
-            self.resolve_create_buffer_mapped(cx, buffer, array_buffer, wgpu_descriptor, valid)
+            assert!(ArrayBuffer::create(
+                *cx,
+                CreateWith::Length(descriptor.size as u32),
+                js_array_buffer.handle_mut(),
+            )
+            .is_ok());
         }
+
+        let buffer = receiver.recv().unwrap();
+        let buff = GPUBuffer::new(
+            &self.global(),
+            self.channel.clone(),
+            buffer,
+            self.device,
+            GPUBufferState::MappedForWriting,
+            wgpu_descriptor.size,
+            wgpu_descriptor.usage.bits(),
+            valid,
+            RootedTraceableBox::from_box(Heap::boxed(js_array_buffer.get())),
+        );
+
+        vec![
+            ObjectValue(buff.reflector().get_jsobject().get()),
+            ObjectValue(js_array_buffer.get()),
+        ]
     }
 
     /// https://gpuweb.github.io/gpuweb/#GPUDevice-createBindGroupLayout