matrix-sdk: prevent dupplicated members requests

matrix_sdk/src/client.rs

@@ -88,16 +88,15 @@ use matrix_sdk_common::{
 };
 
 #[cfg(feature = "encryption")]
-use matrix_sdk_common::{
-    api::r0::{
+use matrix_sdk_common::api::r0::{
     keys::{get_keys, upload_keys, upload_signing_keys::Request as UploadSigningKeysRequest},
     to_device::send_event_to_device::{
         Request as RumaToDeviceRequest, Response as ToDeviceResponse,
     },
-    },
-    locks::Mutex,
 };
 
+use matrix_sdk_common::locks::Mutex;
+
 use crate::{
     error::HttpError,
     http_client::{client_with_config, HttpClient, HttpSend},
@@ -138,6 +137,7 @@ pub struct Client {
     #[cfg(feature = "encryption")]
     /// Lock making sure we're only doing one key claim request at a time.
     key_claim_lock: Arc<Mutex<()>>,
+    pub(crate) members_request_locks: DashMap<RoomId, Arc<Mutex<()>>>,
 }
 
 #[cfg(not(tarpaulin_include))]
@@ -393,6 +393,7 @@ impl Client {
             group_session_locks: DashMap::new(),
             #[cfg(feature = "encryption")]
             key_claim_lock: Arc::new(Mutex::new(())),
+            members_request_locks: DashMap::new(),
         })
     }
 

matrix_sdk/src/room/common.rs

@@ -2,7 +2,9 @@ use matrix_sdk_common::api::r0::{
     membership::{get_member_events, join_room_by_id, leave_room},
     message::get_message_events,
 };
-use std::ops::Deref;
+use matrix_sdk_common::locks::Mutex;
+
+use std::{ops::Deref, sync::Arc};
 
 use crate::{Client, Result, Room, RoomMember};
 
@@ -96,7 +98,22 @@ impl Common {
     }
 
     pub(crate) async fn request_members(&self) -> Result<()> {
-        // TODO: don't send a request if a request is being sent
+        #[allow(clippy::map_clone)]
+        if let Some(mutex) = self
+            .client
+            .members_request_locks
+            .get(self.inner.room_id())
+            .map(|m| m.clone())
+        {
+            mutex.lock().await;
+        } else {
+            let mutex = Arc::new(Mutex::new(()));
+            self.client
+                .members_request_locks
+                .insert(self.inner.room_id().clone(), mutex.clone());
+
+            let _guard = mutex.lock().await;
+
             let request = get_member_events::Request::new(self.inner.room_id());
             let response = self.client.send(request, None).await?;
 
@@ -105,6 +122,11 @@ impl Common {
                 .receive_members(self.inner.room_id(), &response)
                 .await?;
 
+            self.client
+                .members_request_locks
+                .remove(self.inner.room_id());
+        }
+
         Ok(())
     }