0.3.5-alpha.9

crates/common/game-realtime-webtransport-lib/src/webtransport_wasm.rs

@@ -1,5 +1,5 @@
 // file: crates/common/game-realtime-webtransport-lib/src/webtransport_wasm.rs
-// version: 2
+// version: 3
 
 const CERTIFICATE_HASH_SIZE: usize = 32;
 const FRAME_PROTOCOL_ERROR_CODE: u32 = 0x10;
@@ -123,6 +123,36 @@ impl WebTransportSession {
     pub fn endpoint(&self) -> &str {
         return self.inner.url().as_str();
     }
+
+    /// Returns the maximum payload size accepted by the browser WebTransport datagram path.
+    #[must_use]
+    pub fn max_datagram_size(&self) -> usize {
+        return self.inner.max_datagram_size();
+    }
+
+    /// Sends one browser WebTransport datagram without reliability or ordering guarantees.
+    ///
+    /// This capability is intentionally not part of `RealtimeConnection`.
+    pub async fn send_datagram(&self, payload: &[u8]) -> Result<(), game_realtime_transport_lib::TransportError> {
+        let max_datagram_size = self.max_datagram_size();
+        if payload.len() > max_datagram_size {
+            return Err(datagram_too_large(payload.len(), max_datagram_size));
+        }
+        return match self.inner.send_datagram(payload.to_vec().into()).await {
+            Ok(()) => Ok(()),
+            Err(error) => Err(map_write_error(error)),
+        };
+    }
+
+    /// Receives one browser WebTransport datagram without reliability or ordering guarantees.
+    ///
+    /// The caller is responsible for applying any operation deadline required by its use case.
+    pub async fn receive_datagram(&self) -> Result<Vec<u8>, game_realtime_transport_lib::TransportError> {
+        return match self.inner.recv_datagram().await {
+            Ok(payload) => Ok(payload.to_vec()),
+            Err(error) => Err(map_read_error(error)),
+        };
+    }
 }
 
 /// Established browser WebTransport connection carrying the single reliable primary stream.
@@ -588,6 +618,13 @@ fn map_write_error(error: web_transport_wasm::Error) -> game_realtime_transport_
     return transport_error(kind, error.to_string());
 }
 
+fn datagram_too_large(payload_len: usize, max_datagram_size: usize) -> game_realtime_transport_lib::TransportError {
+    return transport_error(
+        game_realtime_transport_lib::TransportErrorKind::MessageTooLarge,
+        format!("WebTransport datagram payload size {payload_len} exceeds current session maximum {max_datagram_size} bytes"),
+    );
+}
+
 fn message_too_large(payload_len: usize, max_message_size: usize) -> game_realtime_transport_lib::TransportError {
     return transport_error(
         game_realtime_transport_lib::TransportErrorKind::MessageTooLarge,