delete unnecessary real_users_cache, fix overwriting push_target iter, add proper function for getting local active users in room

this `real_users_cache` cache seems weird, and i have no idea what
prompted its creation upstream. perhaps they did this because
sqlite was very slow and their rocksdb setup is very poor, so
a "solution" was to stick member counts in memory.
slow iterators, scanning, etc do not apply to conduwuit where
our rocksdb is extremely tuned, and i seriously doubt something
like this would have any real world net-positive performance impact.

also for some reason, there is suspicious logic where we
overwrite the entire push target collection.

both of these things could be a potential cause for receiving
notifications in rooms we've left.

Signed-off-by: strawberry <strawberry@puppygock.gay>

src/service/rooms/state_cache/data.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, sync::Arc};
+use std::collections::HashSet;
 
 use itertools::Itertools;
 use ruma::{
@@ -29,8 +29,6 @@ pub trait Data: Send + Sync {
 
 	fn update_joined_count(&self, room_id: &RoomId) -> Result<()>;
 
-	fn get_our_real_users(&self, room_id: &RoomId) -> Result<Arc<HashSet<OwnedUserId>>>;
-
 	fn appservice_in_room(&self, room_id: &RoomId, appservice: &RegistrationInfo) -> Result<bool>;
 
 	/// Makes a user forget a room.
@@ -48,6 +46,10 @@ pub trait Data: Send + Sync {
 	/// Returns an iterator over all joined members of a room.
 	fn room_members<'a>(&'a self, room_id: &RoomId) -> Box<dyn Iterator<Item = Result<OwnedUserId>> + 'a>;
 
+	/// Returns a vec of all the users joined in a room who are active
+	/// (not guests, not deactivated users)
+	fn active_local_users_in_room(&self, room_id: &RoomId) -> Vec<OwnedUserId>;
+
 	fn room_joined_count(&self, room_id: &RoomId) -> Result<Option<u64>>;
 
 	fn room_invited_count(&self, room_id: &RoomId) -> Result<Option<u64>>;
@@ -225,13 +227,9 @@ impl Data for KeyValueDatabase {
 		let mut joinedcount = 0_u64;
 		let mut invitedcount = 0_u64;
 		let mut joined_servers = HashSet::new();
-		let mut real_users = HashSet::new();
 
 		for joined in self.room_members(room_id).filter_map(Result::ok) {
 			joined_servers.insert(joined.server_name().to_owned());
-			if user_is_local(&joined) && !services().users.is_deactivated(&joined).unwrap_or(true) {
-				real_users.insert(joined);
-			}
 			joinedcount = joinedcount.saturating_add(1);
 		}
 
@@ -245,11 +243,6 @@ impl Data for KeyValueDatabase {
 		self.roomid_invitedcount
 			.insert(room_id.as_bytes(), &invitedcount.to_be_bytes())?;
 
-		self.our_real_users_cache
-			.write()
-			.unwrap()
-			.insert(room_id.to_owned(), Arc::new(real_users));
-
 		for old_joined_server in self.room_servers(room_id).filter_map(Result::ok) {
 			if !joined_servers.remove(&old_joined_server) {
 				// Server not in room anymore
@@ -288,28 +281,6 @@ impl Data for KeyValueDatabase {
 		Ok(())
 	}
 
-	#[tracing::instrument(skip(self, room_id))]
-	fn get_our_real_users(&self, room_id: &RoomId) -> Result<Arc<HashSet<OwnedUserId>>> {
-		let maybe = self
-			.our_real_users_cache
-			.read()
-			.unwrap()
-			.get(room_id)
-			.cloned();
-		if let Some(users) = maybe {
-			Ok(users)
-		} else {
-			self.update_joined_count(room_id)?;
-			Ok(Arc::clone(
-				self.our_real_users_cache
-					.read()
-					.unwrap()
-					.get(room_id)
-					.unwrap(),
-			))
-		}
-	}
-
 	#[tracing::instrument(skip(self, room_id, appservice))]
 	fn appservice_in_room(&self, room_id: &RoomId, appservice: &RegistrationInfo) -> Result<bool> {
 		let maybe = self
@@ -429,6 +400,16 @@ impl Data for KeyValueDatabase {
 		}))
 	}
 
+	/// Returns a vec of all our local users joined in a room who are active
+	/// (not guests / not deactivated users)
+	#[tracing::instrument(skip(self))]
+	fn active_local_users_in_room(&self, room_id: &RoomId) -> Vec<OwnedUserId> {
+		self.room_members(room_id)
+			.filter_map(Result::ok)
+			.filter(|user| user_is_local(user) && !services().users.is_deactivated(user).unwrap_or(true))
+			.collect_vec()
+	}
+
 	/// Returns the number of users which are currently in a room
 	#[tracing::instrument(skip(self))]
 	fn room_joined_count(&self, room_id: &RoomId) -> Result<Option<u64>> {

src/service/rooms/state_cache/mod.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, sync::Arc};
+use std::sync::Arc;
 
 use data::Data;
 use itertools::Itertools;
@@ -212,11 +212,6 @@ impl Service {
 	#[tracing::instrument(skip(self, room_id))]
 	pub fn update_joined_count(&self, room_id: &RoomId) -> Result<()> { self.db.update_joined_count(room_id) }
 
-	#[tracing::instrument(skip(self, room_id))]
-	pub fn get_our_real_users(&self, room_id: &RoomId) -> Result<Arc<HashSet<OwnedUserId>>> {
-		self.db.get_our_real_users(room_id)
-	}
-
 	#[tracing::instrument(skip(self, room_id, appservice))]
 	pub fn appservice_in_room(&self, room_id: &RoomId, appservice: &RegistrationInfo) -> Result<bool> {
 		self.db.appservice_in_room(room_id, appservice)
@@ -278,6 +273,13 @@ impl Service {
 	#[tracing::instrument(skip(self))]
 	pub fn room_joined_count(&self, room_id: &RoomId) -> Result<Option<u64>> { self.db.room_joined_count(room_id) }
 
+	#[tracing::instrument(skip(self))]
+	/// Returns a vec of all the users joined in a room who are active
+	/// (not guests, not deactivated users)
+	pub fn active_local_users_in_room(&self, room_id: &RoomId) -> Vec<OwnedUserId> {
+		self.db.active_local_users_in_room(room_id)
+	}
+
 	#[tracing::instrument(skip(self))]
 	pub fn room_invited_count(&self, room_id: &RoomId) -> Result<Option<u64>> { self.db.room_invited_count(room_id) }