maintain channel subscriptions in RAM (#9512)

This avoids a giant database query on every leave/join event.

Release Notes:

- N/A

crates/collab/src/db/ids.rs

@@ -91,7 +91,9 @@ id_type!(NotificationKindId);
 id_type!(HostedProjectId);
 
 /// ChannelRole gives you permissions for both channels and calls.
-#[derive(Eq, PartialEq, Copy, Clone, Debug, EnumIter, DeriveActiveEnum, Default, Hash)]
+#[derive(
+    Eq, PartialEq, Copy, Clone, Debug, EnumIter, DeriveActiveEnum, Default, Hash, Serialize,
+)]
 #[sea_orm(rs_type = "String", db_type = "String(None)")]
 pub enum ChannelRole {
     /// Admin can read/write and change permissions.

crates/collab/src/db/queries/channels.rs

@@ -45,11 +45,7 @@ impl Database {
         name: &str,
         parent_channel_id: Option<ChannelId>,
         admin_id: UserId,
-    ) -> Result<(
-        Channel,
-        Option<channel_member::Model>,
-        Vec<channel_member::Model>,
-    )> {
+    ) -> Result<(channel::Model, Option<channel_member::Model>)> {
         let name = Self::sanitize_channel_name(name)?;
         self.transaction(move |tx| async move {
             let mut parent = None;
@@ -90,12 +86,7 @@ impl Database {
                 );
             }
 
-            let channel_members = channel_member::Entity::find()
-                .filter(channel_member::Column::ChannelId.eq(channel.root_id()))
-                .all(&*tx)
-                .await?;
-
-            Ok((Channel::from_model(channel), membership, channel_members))
+            Ok((channel, membership))
         })
         .await
     }
@@ -181,7 +172,7 @@ impl Database {
         channel_id: ChannelId,
         visibility: ChannelVisibility,
         admin_id: UserId,
-    ) -> Result<(Channel, Vec<channel_member::Model>)> {
+    ) -> Result<channel::Model> {
         self.transaction(move |tx| async move {
             let channel = self.get_channel_internal(channel_id, &tx).await?;
             self.check_user_is_channel_admin(&channel, admin_id, &tx)
@@ -214,12 +205,7 @@ impl Database {
             model.visibility = ActiveValue::Set(visibility);
             let channel = model.update(&*tx).await?;
 
-            let channel_members = channel_member::Entity::find()
-                .filter(channel_member::Column::ChannelId.eq(channel.root_id()))
-                .all(&*tx)
-                .await?;
-
-            Ok((Channel::from_model(channel), channel_members))
+            Ok(channel)
         })
         .await
     }
@@ -245,21 +231,12 @@ impl Database {
         &self,
         channel_id: ChannelId,
         user_id: UserId,
-    ) -> Result<(Vec<ChannelId>, Vec<UserId>)> {
+    ) -> Result<(ChannelId, Vec<ChannelId>)> {
         self.transaction(move |tx| async move {
             let channel = self.get_channel_internal(channel_id, &tx).await?;
             self.check_user_is_channel_admin(&channel, user_id, &tx)
                 .await?;
 
-            let members_to_notify: Vec<UserId> = channel_member::Entity::find()
-                .filter(channel_member::Column::ChannelId.eq(channel.root_id()))
-                .select_only()
-                .column(channel_member::Column::UserId)
-                .distinct()
-                .into_values::<_, QueryUserIds>()
-                .all(&*tx)
-                .await?;
-
             let channels_to_remove = self
                 .get_channel_descendants_excluding_self([&channel], &tx)
                 .await?
@@ -273,7 +250,7 @@ impl Database {
                 .exec(&*tx)
                 .await?;
 
-            Ok((channels_to_remove, members_to_notify))
+            Ok((channel.root_id(), channels_to_remove))
         })
         .await
     }
@@ -343,7 +320,7 @@ impl Database {
         channel_id: ChannelId,
         admin_id: UserId,
         new_name: &str,
-    ) -> Result<(Channel, Vec<channel_member::Model>)> {
+    ) -> Result<channel::Model> {
         self.transaction(move |tx| async move {
             let new_name = Self::sanitize_channel_name(new_name)?.to_string();
 
@@ -355,12 +332,7 @@ impl Database {
             model.name = ActiveValue::Set(new_name.clone());
             let channel = model.update(&*tx).await?;
 
-            let channel_members = channel_member::Entity::find()
-                .filter(channel_member::Column::ChannelId.eq(channel.root_id()))
-                .all(&*tx)
-                .await?;
-
-            Ok((Channel::from_model(channel), channel_members))
+            Ok(channel)
         })
         .await
     }
@@ -984,7 +956,7 @@ impl Database {
         channel_id: ChannelId,
         new_parent_id: ChannelId,
         admin_id: UserId,
-    ) -> Result<(Vec<Channel>, Vec<channel_member::Model>)> {
+    ) -> Result<(ChannelId, Vec<Channel>)> {
         self.transaction(|tx| async move {
             let channel = self.get_channel_internal(channel_id, &tx).await?;
             self.check_user_is_channel_admin(&channel, admin_id, &tx)
@@ -1039,12 +1011,7 @@ impl Database {
                 .map(|c| Channel::from_model(c))
                 .collect::<Vec<_>>();
 
-            let channel_members = channel_member::Entity::find()
-                .filter(channel_member::Column::ChannelId.eq(root_id))
-                .all(&*tx)
-                .await?;
-
-            Ok((channels, channel_members))
+            Ok((root_id, channels))
         })
         .await
     }

crates/collab/src/db/queries/rooms.rs

@@ -52,12 +52,7 @@ impl Database {
             );
 
             let (channel, room) = self.get_channel_room(room_id, &tx).await?;
-            let channel_members;
-            if let Some(channel) = &channel {
-                channel_members = self.get_channel_participants(channel, &tx).await?;
-            } else {
-                channel_members = Vec::new();
-
+            if channel.is_none() {
                 // Delete the room if it becomes empty.
                 if room.participants.is_empty() {
                     project::Entity::delete_many()
@@ -70,8 +65,7 @@ impl Database {
 
             Ok(RefreshedRoom {
                 room,
-                channel_id: channel.map(|channel| channel.id),
-                channel_members,
+                channel,
                 stale_participant_user_ids,
                 canceled_calls_to_user_ids,
             })
@@ -349,8 +343,7 @@ impl Database {
             let room = self.get_room(room_id, &tx).await?;
             Ok(JoinRoom {
                 room,
-                channel_id: None,
-                channel_members: vec![],
+                channel: None,
             })
         })
         .await
@@ -446,11 +439,9 @@ impl Database {
 
         let (channel, room) = self.get_channel_room(room_id, &tx).await?;
         let channel = channel.ok_or_else(|| anyhow!("no channel for room"))?;
-        let channel_members = self.get_channel_participants(&channel, tx).await?;
         Ok(JoinRoom {
             room,
-            channel_id: Some(channel.id),
-            channel_members,
+            channel: Some(channel),
         })
     }
 
@@ -736,16 +727,10 @@ impl Database {
             }
 
             let (channel, room) = self.get_channel_room(room_id, &tx).await?;
-            let channel_members = if let Some(channel) = &channel {
-                self.get_channel_participants(&channel, &tx).await?
-            } else {
-                Vec::new()
-            };
 
             Ok(RejoinedRoom {
                 room,
-                channel_id: channel.map(|channel| channel.id),
-                channel_members,
+                channel,
                 rejoined_projects,
                 reshared_projects,
             })
@@ -902,15 +887,9 @@ impl Database {
                     false
                 };
 
-                let channel_members = if let Some(channel) = &channel {
-                    self.get_channel_participants(channel, &tx).await?
-                } else {
-                    Vec::new()
-                };
                 let left_room = LeftRoom {
                     room,
-                    channel_id: channel.map(|channel| channel.id),
-                    channel_members,
+                    channel,
                     left_projects,
                     canceled_calls_to_user_ids,
                     deleted,

crates/collab/src/db/tests/channel_tests.rs

@@ -109,10 +109,9 @@ async fn test_channels(db: &Arc<Database>) {
     assert!(db.get_channel(crdb_id, a_id).await.is_err());
 
     // Remove a channel tree
-    let (mut channel_ids, user_ids) = db.delete_channel(rust_id, a_id).await.unwrap();
+    let (_, mut channel_ids) = db.delete_channel(rust_id, a_id).await.unwrap();
     channel_ids.sort();
     assert_eq!(channel_ids, &[rust_id, cargo_id, cargo_ra_id]);
-    assert_eq!(user_ids, &[a_id]);
 
     assert!(db.get_channel(rust_id, a_id).await.is_err());
     assert!(db.get_channel(cargo_id, a_id).await.is_err());