feat(jupyter): send binary data with `Deno.jupyter.broadcast` (#20755)

Adds `buffers` to the `Deno.jupyter.broadcast` API to send binary data
via comms. This affords the ability to send binary data via websockets
to the jupyter widget frontend.

1 files changed, 36 insertions, 22 deletions

diff --git a/cli/tools/jupyter/jupyter_msg.rs b/cli/tools/jupyter/jupyter_msg.rs
index beb9f34e4..da6654cae 100644
--- a/cli/tools/jupyter/jupyter_msg.rs
+++ b/cli/tools/jupyter/jupyter_msg.rs
@@ -122,6 +122,7 @@ pub(crate) struct JupyterMessage {
   parent_header: serde_json::Value,
   metadata: serde_json::Value,
   content: serde_json::Value,
+  buffers: Vec<Bytes>,
 }
 
 const DELIMITER: &[u8] = b"<IDS|MSG>";
@@ -146,6 +147,11 @@ impl JupyterMessage {
       parent_header: serde_json::from_slice(&raw_message.jparts[1])?,
       metadata: serde_json::from_slice(&raw_message.jparts[2])?,
       content: serde_json::from_slice(&raw_message.jparts[3])?,
+      buffers: if raw_message.jparts.len() > 4 {
+        raw_message.jparts[4..].to_vec()
+      } else {
+        vec![]
+      },
     })
   }
 
@@ -179,6 +185,7 @@ impl JupyterMessage {
       parent_header: self.header.clone(),
       metadata: json!({}),
       content: json!({}),
+      buffers: vec![],
     }
   }
 
@@ -214,36 +221,43 @@ impl JupyterMessage {
     self
   }
 
+  pub(crate) fn with_buffers(mut self, buffers: Vec<Bytes>) -> JupyterMessage {
+    self.buffers = buffers;
+    self
+  }
+
   pub(crate) async fn send<S: zeromq::SocketSend>(
     &self,
     connection: &mut Connection<S>,
   ) -> Result<(), AnyError> {
     // If performance is a concern, we can probably avoid the clone and to_vec calls with a bit
     // of refactoring.
+    let mut jparts: Vec<Bytes> = vec![
+      serde_json::to_string(&self.header)
+        .unwrap()
+        .as_bytes()
+        .to_vec()
+        .into(),
+      serde_json::to_string(&self.parent_header)
+        .unwrap()
+        .as_bytes()
+        .to_vec()
+        .into(),
+      serde_json::to_string(&self.metadata)
+        .unwrap()
+        .as_bytes()
+        .to_vec()
+        .into(),
+      serde_json::to_string(&self.content)
+        .unwrap()
+        .as_bytes()
+        .to_vec()
+        .into(),
+    ];
+    jparts.extend_from_slice(&self.buffers);
     let raw_message = RawMessage {
       zmq_identities: self.zmq_identities.clone(),
-      jparts: vec![
-        serde_json::to_string(&self.header)
-          .unwrap()
-          .as_bytes()
-          .to_vec()
-          .into(),
-        serde_json::to_string(&self.parent_header)
-          .unwrap()
-          .as_bytes()
-          .to_vec()
-          .into(),
-        serde_json::to_string(&self.metadata)
-          .unwrap()
-          .as_bytes()
-          .to_vec()
-          .into(),
-        serde_json::to_string(&self.content)
-          .unwrap()
-          .as_bytes()
-          .to_vec()
-          .into(),
-      ],
+      jparts,
     };
     raw_message.send(connection).await
   }