feat: bring back WebGPU (#20812)

Signed-off-by: Leo Kettmeir <crowlkats@toaxl.com>
Co-authored-by: Kenta Moriuchi <moriken@kimamass.com>
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/ext/webgpu/buffer.rs b/ext/webgpu/buffer.rs
new file mode 100644
index 000000000..2f9724825
--- /dev/null
+++ b/ext/webgpu/buffer.rs
@@ -0,0 +1,205 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use deno_core::error::type_error;
+use deno_core::error::AnyError;
+use deno_core::futures::channel::oneshot;
+use deno_core::op2;
+use deno_core::OpState;
+use deno_core::Resource;
+use deno_core::ResourceId;
+use std::borrow::Cow;
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::time::Duration;
+use wgpu_core::resource::BufferAccessResult;
+
+use super::error::DomExceptionOperationError;
+use super::error::WebGpuResult;
+
+pub(crate) struct WebGpuBuffer(
+  pub(crate) super::Instance,
+  pub(crate) wgpu_core::id::BufferId,
+);
+impl Resource for WebGpuBuffer {
+  fn name(&self) -> Cow<str> {
+    "webGPUBuffer".into()
+  }
+
+  fn close(self: Rc<Self>) {
+    let instance = &self.0;
+    gfx_select!(self.1 => instance.buffer_drop(self.1, true));
+  }
+}
+
+struct WebGpuBufferMapped(*mut u8, usize);
+impl Resource for WebGpuBufferMapped {
+  fn name(&self) -> Cow<str> {
+    "webGPUBufferMapped".into()
+  }
+}
+
+#[op2]
+#[serde]
+pub fn op_webgpu_create_buffer(
+  state: &mut OpState,
+  #[smi] device_rid: ResourceId,
+  #[string] label: Cow<str>,
+  #[number] size: u64,
+  usage: u32,
+  mapped_at_creation: bool,
+) -> Result<WebGpuResult, AnyError> {
+  let instance = state.borrow::<super::Instance>();
+  let device_resource = state
+    .resource_table
+    .get::<super::WebGpuDevice>(device_rid)?;
+  let device = device_resource.1;
+
+  let descriptor = wgpu_core::resource::BufferDescriptor {
+    label: Some(label),
+    size,
+    usage: wgpu_types::BufferUsages::from_bits(usage)
+      .ok_or_else(|| type_error("usage is not valid"))?,
+    mapped_at_creation,
+  };
+
+  gfx_put!(device => instance.device_create_buffer(
+    device,
+    &descriptor,
+    ()
+  ) => state, WebGpuBuffer)
+}
+
+#[op2(async)]
+#[serde]
+pub async fn op_webgpu_buffer_get_map_async(
+  state: Rc<RefCell<OpState>>,
+  #[smi] buffer_rid: ResourceId,
+  #[smi] device_rid: ResourceId,
+  mode: u32,
+  #[number] offset: u64,
+  #[number] size: u64,
+) -> Result<WebGpuResult, AnyError> {
+  let (sender, receiver) = oneshot::channel::<BufferAccessResult>();
+
+  let device;
+  {
+    let state_ = state.borrow();
+    let instance = state_.borrow::<super::Instance>();
+    let buffer_resource =
+      state_.resource_table.get::<WebGpuBuffer>(buffer_rid)?;
+    let buffer = buffer_resource.1;
+    let device_resource = state_
+      .resource_table
+      .get::<super::WebGpuDevice>(device_rid)?;
+    device = device_resource.1;
+
+    let callback = Box::new(move |status| {
+      sender.send(status).unwrap();
+    });
+
+    // TODO(lucacasonato): error handling
+    let maybe_err = gfx_select!(buffer => instance.buffer_map_async(
+            buffer,
+            offset..(offset + size),
+            wgpu_core::resource::BufferMapOperation {
+                host: match mode {
+                    1 => wgpu_core::device::HostMap::Read,
+                    2 => wgpu_core::device::HostMap::Write,
+                    _ => unreachable!(),
+                },
+                callback: wgpu_core::resource::BufferMapCallback::from_rust(callback),
+            }
+        ))
+        .err();
+
+    if maybe_err.is_some() {
+      return Ok(WebGpuResult::maybe_err(maybe_err));
+    }
+  }
+
+  let done = Rc::new(RefCell::new(false));
+  let done_ = done.clone();
+  let device_poll_fut = async move {
+    while !*done.borrow() {
+      {
+        let state = state.borrow();
+        let instance = state.borrow::<super::Instance>();
+        gfx_select!(device => instance.device_poll(device, wgpu_types::Maintain::Wait))
+                    .unwrap();
+      }
+      tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    Ok::<(), AnyError>(())
+  };
+
+  let receiver_fut = async move {
+    receiver.await??;
+    let mut done = done_.borrow_mut();
+    *done = true;
+    Ok::<(), AnyError>(())
+  };
+
+  tokio::try_join!(device_poll_fut, receiver_fut)?;
+
+  Ok(WebGpuResult::empty())
+}
+
+#[op2]
+#[serde]
+pub fn op_webgpu_buffer_get_mapped_range(
+  state: &mut OpState,
+  #[smi] buffer_rid: ResourceId,
+  #[number] offset: u64,
+  #[number] size: Option<u64>,
+  #[buffer] buf: &mut [u8],
+) -> Result<WebGpuResult, AnyError> {
+  let instance = state.borrow::<super::Instance>();
+  let buffer_resource = state.resource_table.get::<WebGpuBuffer>(buffer_rid)?;
+  let buffer = buffer_resource.1;
+
+  let (slice_pointer, range_size) =
+    gfx_select!(buffer => instance.buffer_get_mapped_range(
+      buffer,
+      offset,
+      size
+    ))
+    .map_err(|e| DomExceptionOperationError::new(&e.to_string()))?;
+
+  // SAFETY: guarantee to be safe from wgpu
+  let slice = unsafe {
+    std::slice::from_raw_parts_mut(slice_pointer, range_size as usize)
+  };
+  buf.copy_from_slice(slice);
+
+  let rid = state
+    .resource_table
+    .add(WebGpuBufferMapped(slice_pointer, range_size as usize));
+
+  Ok(WebGpuResult::rid(rid))
+}
+
+#[op2]
+#[serde]
+pub fn op_webgpu_buffer_unmap(
+  state: &mut OpState,
+  #[smi] buffer_rid: ResourceId,
+  #[smi] mapped_rid: ResourceId,
+  #[buffer] buf: Option<&[u8]>,
+) -> Result<WebGpuResult, AnyError> {
+  let mapped_resource = state
+    .resource_table
+    .take::<WebGpuBufferMapped>(mapped_rid)?;
+  let instance = state.borrow::<super::Instance>();
+  let buffer_resource = state.resource_table.get::<WebGpuBuffer>(buffer_rid)?;
+  let buffer = buffer_resource.1;
+
+  if let Some(buf) = buf {
+    // SAFETY: guarantee to be safe from wgpu
+    let slice = unsafe {
+      std::slice::from_raw_parts_mut(mapped_resource.0, mapped_resource.1)
+    };
+    slice.copy_from_slice(buf);
+  }
+
+  gfx_ok!(buffer => instance.buffer_unmap(buffer))
+}