Merge pull request #16 from MattiasBuelens/no-respond-on-cancel

Stop calling byobRequest.respond(0) on cancel

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+* Stop calling `byobRequest.respond(0)` on cancel ([#16](https://github.com/MattiasBuelens/wasm-streams/pull/16))
+
 ## v0.3.0 (2022-10-16)
 
 * Added support for web workers, by removing usage of [JavaScript snippets](https://rustwasm.github.io/docs/wasm-bindgen/reference/js-snippets.html). ([#13](https://github.com/MattiasBuelens/wasm-streams/issues/13), [#14](https://github.com/MattiasBuelens/wasm-streams/pull/14))

src/readable/into_underlying_byte_source.rs

@@ -78,10 +78,6 @@ impl Drop for IntoUnderlyingByteSource {
  if let Some(handle) = self.pull_handle.take() {
  handle.abort();
  }
- // Close the pending BYOB request, if any. This is necessary for cancellation.
- if let Some(request) = self.controller.take().and_then(|c| c.byob_request()) {
- request.respond(0);
- }
  }
 }
 
@@ -106,9 +102,9 @@ impl Inner {
  // after the stream has closed or encountered an error.
  let async_read = self.async_read.as_mut().unwrap_throw();
  // We set autoAllocateChunkSize, so there should always be a BYOB request.
- let mut request = ByobRequestGuard::new(controller.byob_request().unwrap_throw());
+ let request = controller.byob_request().unwrap_throw();
  // Resize the buffer to fit the BYOB request.
- let request_view = request.view();
+ let request_view = request.view().unwrap_throw();
  let request_len = clamp_to_usize(request_view.byte_length());
  if self.buffer.len() < request_len {
  self.buffer.resize(request_len, 0);
@@ -117,8 +113,8 @@ impl Inner {
  Ok(0) => {
  // The stream has closed, drop it.
  self.discard();
- controller.close();
- request.respond(0);
+ controller.close()?;
+ request.respond(0)?;
  }
  Ok(bytes_read) => {
  // Copy read bytes from buffer to BYOB request view
@@ -131,7 +127,7 @@ impl Inner {
  );
  dest.copy_from(&self.buffer[0..bytes_read]);
  // Respond to BYOB request
- request.respond(bytes_read_u32);
+ request.respond(bytes_read_u32)?;
  }
  Err(err) => {
  // The stream encountered an error, drop it.
@@ -148,29 +144,3 @@ impl Inner {
  self.buffer = Vec::new();
  }
 }
-
-#[derive(Debug)]
-struct ByobRequestGuard(Option<sys::ReadableStreamBYOBRequest>);
-
-impl ByobRequestGuard {
- fn new(request: sys::ReadableStreamBYOBRequest) -> Self {
- Self(Some(request))
- }
-
- fn view(&mut self) -> sys::ArrayBufferView {
- self.0.as_mut().unwrap_throw().view().unwrap_throw()
- }
-
- fn respond(mut self, bytes_read: u32) {
- self.0.take().unwrap_throw().respond(bytes_read);
- }
-}
-
-impl Drop for ByobRequestGuard {
- fn drop(&mut self) {
- // Close the BYOB request, if still pending. This is necessary for cancellation.
- if let Some(request) = self.0.take() {
- request.respond(0);
- }
- }
-}

src/readable/into_underlying_source.rs

@@ -82,11 +82,11 @@ impl Inner {
  // after the stream has closed or encountered an error.
  let stream = self.stream.as_mut().unwrap_throw();
  match stream.try_next().await {
- Ok(Some(chunk)) => controller.enqueue(&chunk),
+ Ok(Some(chunk)) => controller.enqueue(&chunk)?,
  Ok(None) => {
  // The stream has closed, drop it.
  self.stream = None;
- controller.close();
+ controller.close()?;
  }
  Err(err) => {
  // The stream encountered an error, drop it.

src/readable/sys.rs

@@ -72,11 +72,11 @@ extern "C" {
  #[wasm_bindgen(method, getter, js_name = desiredSize)]
  pub fn desired_size(this: &ReadableStreamDefaultController) -> Option<f64>;
 
- #[wasm_bindgen(method, js_name = close)]
- pub fn close(this: &ReadableStreamDefaultController);
+ #[wasm_bindgen(method, catch, js_name = close)]
+ pub fn close(this: &ReadableStreamDefaultController) -> Result<(), JsValue>;
 
- #[wasm_bindgen(method, js_name = enqueue)]
- pub fn enqueue(this: &ReadableStreamDefaultController, chunk: &JsValue);
+ #[wasm_bindgen(method, catch, js_name = enqueue)]
+ pub fn enqueue(this: &ReadableStreamDefaultController, chunk: &JsValue) -> Result<(), JsValue>;
 
  #[wasm_bindgen(method, js_name = error)]
  pub fn error(this: &ReadableStreamDefaultController, error: &JsValue);
@@ -94,11 +94,14 @@ extern "C" {
  #[wasm_bindgen(method, getter, js_name = desiredSize)]
  pub fn desired_size(this: &ReadableByteStreamController) -> Option<f64>;
 
- #[wasm_bindgen(method, js_name = close)]
- pub fn close(this: &ReadableByteStreamController);
+ #[wasm_bindgen(method, catch, js_name = close)]
+ pub fn close(this: &ReadableByteStreamController) -> Result<(), JsValue>;
 
- #[wasm_bindgen(method, js_name = enqueue)]
- pub fn enqueue(this: &ReadableByteStreamController, chunk: &ArrayBufferView);
+ #[wasm_bindgen(method, catch, js_name = enqueue)]
+ pub fn enqueue(
+ this: &ReadableByteStreamController,
+ chunk: &ArrayBufferView,
+ ) -> Result<(), JsValue>;
 
  #[wasm_bindgen(method, js_name = error)]
  pub fn error(this: &ReadableByteStreamController, error: &JsValue);
@@ -113,11 +116,14 @@ extern "C" {
  #[wasm_bindgen(method, getter, js_name = view)]
  pub fn view(this: &ReadableStreamBYOBRequest) -> Option<ArrayBufferView>;
 
- #[wasm_bindgen(method, js_name = respond)]
- pub fn respond(this: &ReadableStreamBYOBRequest, bytes_written: u32);
+ #[wasm_bindgen(method, catch, js_name = respond)]
+ pub fn respond(this: &ReadableStreamBYOBRequest, bytes_written: u32) -> Result<(), JsValue>;
 
- #[wasm_bindgen(method, js_name = respondWithNewView)]
- pub fn respond_with_new_view(this: &ReadableStreamBYOBRequest, view: &ArrayBufferView);
+ #[wasm_bindgen(method, catch, js_name = respondWithNewView)]
+ pub fn respond_with_new_view(
+ this: &ReadableStreamBYOBRequest,
+ view: &ArrayBufferView,
+ ) -> Result<(), JsValue>;
 }
 
 #[wasm_bindgen]