multistore_cf_workers/
body.rs

1//! Zero-copy body wrapper for Cloudflare Workers.
2//!
3//! Holds the raw `ReadableStream` from an incoming request so it can be
4//! forwarded to the backend without copying through WASM memory.
5
6use bytes::Bytes;
7
8/// Zero-copy body wrapper. Holds the raw `ReadableStream` from the incoming
9/// request, passing it through the Gateway untouched for Forward requests.
10pub struct JsBody(Option<web_sys::ReadableStream>);
11
12impl JsBody {
13    /// Wrap an optional `ReadableStream` from a `web_sys::Request`.
14    pub fn new(stream: Option<web_sys::ReadableStream>) -> Self {
15        Self(stream)
16    }
17
18    /// Borrow the inner stream, if present.
19    pub fn stream(&self) -> Option<&web_sys::ReadableStream> {
20        self.0.as_ref()
21    }
22}
23
24// SAFETY: Workers is single-threaded; these are required by Gateway's generic bounds.
25unsafe impl Send for JsBody {}
26unsafe impl Sync for JsBody {}
27
28/// Materialize a `JsBody` into `Bytes` for the NeedsBody path.
29///
30/// Uses the `Response::arrayBuffer()` JS trick: wrap the stream in a
31/// `web_sys::Response`, call `.array_buffer()`, and convert via `Uint8Array`.
32/// This is only used for small multipart payloads.
33pub async fn collect_js_body(body: JsBody) -> std::result::Result<Bytes, String> {
34    match body.0 {
35        None => Ok(Bytes::new()),
36        Some(stream) => {
37            let resp = web_sys::Response::new_with_opt_readable_stream(Some(&stream))
38                .map_err(|e| format!("Response::new failed: {:?}", e))?;
39            let promise = resp
40                .array_buffer()
41                .map_err(|e| format!("arrayBuffer() failed: {:?}", e))?;
42            let buf = wasm_bindgen_futures::JsFuture::from(promise)
43                .await
44                .map_err(|e| format!("arrayBuffer await failed: {:?}", e))?;
45            let uint8 = js_sys::Uint8Array::new(&buf);
46            Ok(Bytes::from(uint8.to_vec()))
47        }
48    }
49}
multistore_cf_workers/body.rs

multistore_cf_workers/
body.rs
