bypass SM for in-memory streams in request bodies, dis-allow other cases in sync XHR

components/script/body.rs

@@ -58,6 +58,7 @@ struct TransmitBodyConnectHandler {
     canceller: TaskCanceller,
     bytes_sender: Option<IpcSender<Vec<u8>>>,
     control_sender: IpcSender<BodyChunkRequest>,
+    in_memory: Option<Vec<u8>>,
 }
 
 impl TransmitBodyConnectHandler {
@@ -66,6 +67,7 @@ impl TransmitBodyConnectHandler {
         task_source: NetworkingTaskSource,
         canceller: TaskCanceller,
         control_sender: IpcSender<BodyChunkRequest>,
+        in_memory: Option<Vec<u8>>,
     ) -> TransmitBodyConnectHandler {
         TransmitBodyConnectHandler {
             stream: stream,
@@ -73,6 +75,7 @@ impl TransmitBodyConnectHandler {
             canceller,
             bytes_sender: None,
             control_sender,
+            in_memory,
         }
     }
 
@@ -97,6 +100,12 @@ impl TransmitBodyConnectHandler {
             .clone()
             .expect("No bytes sender to transmit chunk.");
 
+        // In case of the data being in-memory, send everything in one chunk, by-passing SpiderMonkey.
+        if let Some(bytes) = self.in_memory.take() {
+            let _ = bytes_sender.send(bytes);
+            return;
+        }
+
         let _ = self.task_source.queue_with_canceller(
             task!(setup_native_body_promise_handler: move || {
                 // Step 1, Let body be request’s body.
@@ -247,11 +256,15 @@ impl ExtractedBody {
         let task_source = global.networking_task_source();
         let canceller = global.task_canceller(TaskSourceName::Networking);
 
+        // In case of the data being in-memory, send everything in one chunk, by-passing SM.
+        let in_memory = stream.get_in_memory_bytes();
+
         let mut body_handler = TransmitBodyConnectHandler::new(
             trusted_stream,
             task_source,
             canceller,
             chunk_request_sender.clone(),
+            in_memory,
         );
 
         ROUTER.add_route(
@@ -281,6 +294,11 @@ impl ExtractedBody {
         // Also return the stream for this body, which can be used by script to consume it.
         (request_body, stream)
     }
+
+    /// Is the data of the stream of this extracted body available in memory?
+    pub fn in_memory(&self) -> bool {
+        self.stream.in_memory()
+    }
 }
 
 /// <https://fetch.spec.whatwg.org/#concept-bodyinit-extract>

components/script/dom/readablestream.rs

@@ -196,6 +196,21 @@ impl ReadableStream {
             .close(cx, handle);
     }
 
+    /// Does the stream have all data in memory?
+    pub fn in_memory(&self) -> bool {
+        self.external_underlying_source
+            .as_ref()
+            .map(|source| source.in_memory())
+            .unwrap_or(false)
+    }
+
+    /// Return bytes for synchronous use, if the stream has all data in memory.
+    pub fn get_in_memory_bytes(&self) -> Option<Vec<u8>> {
+        self.external_underlying_source
+            .as_ref()
+            .and_then(|source| source.get_in_memory_bytes())
+    }
+
     /// Acquires a reader and locks the stream,
     /// must be done before `read_a_chunk`.
     #[allow(unsafe_code)]
@@ -372,22 +387,37 @@ struct ExternalUnderlyingSourceController {
     buffer: RefCell<Vec<u8>>,
     /// Has the stream been closed by native code?
     closed: Cell<bool>,
+    /// Does this stream contains all it's data in memory?
+    in_memory: Cell<bool>,
 }
 
 impl ExternalUnderlyingSourceController {
     fn new(source: ExternalUnderlyingSource) -> ExternalUnderlyingSourceController {
-        let buffer = match source {
-            ExternalUnderlyingSource::Blob(size) | ExternalUnderlyingSource::Memory(size) => {
-                Vec::with_capacity(size)
-            },
-            ExternalUnderlyingSource::FetchResponse => vec![],
+        let (buffer, in_mem) = match source {
+            ExternalUnderlyingSource::Blob(size) => (Vec::with_capacity(size), false),
+            ExternalUnderlyingSource::Memory(size) => (Vec::with_capacity(size), true),
+            ExternalUnderlyingSource::FetchResponse => (vec![], false),
         };
         ExternalUnderlyingSourceController {
             buffer: RefCell::new(buffer),
             closed: Cell::new(false),
+            in_memory: Cell::new(in_mem),
         }
     }
 
+    /// Does the stream have all data in memory?
+    pub fn in_memory(&self) -> bool {
+        self.in_memory.get()
+    }
+
+    /// Return bytes synchronously if the stream has all data in memory.
+    pub fn get_in_memory_bytes(&self) -> Option<Vec<u8>> {
+        if self.in_memory.get() {
+            return Some(self.buffer.borrow().clone());
+        }
+        None
+    }
+
     /// Signal available bytes if the stream is currently readable.
     #[allow(unsafe_code)]
     fn maybe_signal_available_bytes(

components/script/dom/xmlhttprequest.rs

@@ -580,7 +580,13 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                 })
             },
             Some(DocumentOrBodyInit::Blob(ref b)) => {
-                Some(b.extract(&self.global()).expect("Couldn't extract body."))
+                let extracted_body = b.extract(&self.global()).expect("Couldn't extract body.");
+                if !extracted_body.in_memory() && self.sync.get() {
+                    warn!("Sync XHR with not in-memory Blob as body not supported");
+                    None
+                } else {
+                    Some(extracted_body)
+                }
             },
             Some(DocumentOrBodyInit::FormData(ref formdata)) => Some(
                 formdata
@@ -620,21 +626,23 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                 })
             },
             Some(DocumentOrBodyInit::ReadableStream(ref stream)) => {
-                // TODO:
-                // 1. If the keepalive flag is set, then throw a TypeError.
+                if self.sync.get() {
+                    warn!("Sync XHR with ReadableStream as body not supported");
+                    None
+                } else {
+                    if stream.is_locked() || stream.is_disturbed() {
+                        return Err(Error::Type(
+                            "The body's stream is disturbed or locked".to_string(),
+                        ));
+                    }
 
-                if stream.is_locked() || stream.is_disturbed() {
-                    return Err(Error::Type(
-                        "The body's stream is disturbed or locked".to_string(),
-                    ));
+                    Some(ExtractedBody {
+                        stream: stream.clone(),
+                        total_bytes: None,
+                        content_type: None,
+                        source: BodySource::Null,
+                    })
                 }
-
-                Some(ExtractedBody {
-                    stream: stream.clone(),
-                    total_bytes: None,
-                    content_type: None,
-                    source: BodySource::Null,
-                })
             },
             None => None,
         };