base_client: Expose the method to check if a group session needs to be shared.

src/base_client.rs

@@ -399,6 +399,25 @@ impl Client {
         }
     }
 
+    /// Should the client share a group session for the given room.
+    ///
+    /// Returns true if a session needs to be shared before room messages can be
+    /// encrypted, false if one is already shared and ready to encrypt room
+    /// messages.
+    ///
+    /// This should be called every time a new room message wants to be sent out
+    /// since group sessions can expire at any time.
+    #[cfg(feature = "encryption")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "encryption")))]
+    pub async fn should_share_group_session(&self, room_id: &RoomId) -> bool {
+        let olm = self.olm.lock().await;
+
+        match &*olm {
+            Some(o) => o.should_share_group_session(room_id),
+            None => false,
+        }
+    }
+
     /// Should users be queried for their device keys.
     #[cfg(feature = "encryption")]
     #[cfg_attr(docsrs, doc(cfg(feature = "encryption")))]