move and improve common-rooms related

Signed-off-by: Jason Volk <jason@zemos.net>

src/api/client/presence.rs

@@ -52,8 +52,8 @@ pub(crate) async fn get_presence_route(
 
 	let has_shared_rooms = services
 		.rooms
-		.user
-		.has_shared_rooms(sender_user, &body.user_id)
+		.state_cache
+		.user_sees_user(sender_user, &body.user_id)
 		.await;
 
 	if has_shared_rooms {

src/api/client/sync/mod.rs

@@ -52,7 +52,7 @@ async fn share_encrypted_room(
 ) -> bool {
 	services
 		.rooms
-		.user
+		.state_cache
 		.get_shared_rooms(sender_user, user_id)
 		.ready_filter(|&room_id| Some(room_id) != ignore_room)
 		.any(|other_room_id| {

src/api/client/unstable.rs

@@ -55,7 +55,7 @@ pub(crate) async fn get_mutual_rooms_route(
 
 	let mutual_rooms: Vec<OwnedRoomId> = services
 		.rooms
-		.user
+		.state_cache
 		.get_shared_rooms(sender_user, &body.user_id)
 		.map(ToOwned::to_owned)
 		.collect()

src/api/client/user_directory.rs

@@ -71,8 +71,8 @@ pub(crate) async fn search_users_route(
 		} else {
 			let user_is_in_shared_rooms = services
 				.rooms
-				.user
-				.has_shared_rooms(sender_user, &user.user_id)
+				.state_cache
+				.user_sees_user(sender_user, &user.user_id)
 				.await;
 
 			if user_is_in_shared_rooms {

src/service/rooms/state_cache/mod.rs

@@ -10,7 +10,7 @@ use conduit::{
 	warn, Result,
 };
 use database::{serialize_to_vec, Deserialized, Ignore, Interfix, Json, Map};
-use futures::{future::join4, stream::iter, Stream, StreamExt};
+use futures::{future::join4, pin_mut, stream::iter, Stream, StreamExt};
 use itertools::Itertools;
 use ruma::{
 	events::{
@@ -385,16 +385,21 @@ impl Service {
 	/// Returns true if user_a and user_b share at least one room.
 	#[tracing::instrument(skip(self), level = "debug")]
 	pub async fn user_sees_user(&self, user_a: &UserId, user_b: &UserId) -> bool {
-		// Minimize number of point-queries by iterating user with least nr rooms
-		let (a, b) = if self.rooms_joined(user_a).count().await < self.rooms_joined(user_b).count().await {
-			(user_a, user_b)
-		} else {
-			(user_b, user_a)
-		};
+		let get_shared_rooms = self.get_shared_rooms(user_a, user_b);
 
-		self.rooms_joined(a)
-			.any(|room_id| self.is_joined(b, room_id))
-			.await
+		pin_mut!(get_shared_rooms);
+		get_shared_rooms.next().await.is_some()
+	}
+
+	/// List the rooms common between two users
+	pub fn get_shared_rooms<'a>(
+		&'a self, user_a: &'a UserId, user_b: &'a UserId,
+	) -> impl Stream<Item = &RoomId> + Send + 'a {
+		use conduit::utils::set;
+
+		let a = self.rooms_joined(user_a);
+		let b = self.rooms_joined(user_b);
+		set::intersection_sorted_stream2(a, b)
 	}
 
 	/// Returns an iterator of all joined members of a room.

src/service/rooms/user/mod.rs

@@ -2,7 +2,6 @@ use std::sync::Arc;
 
 use conduit::{implement, Result};
 use database::{Deserialized, Map};
-use futures::{pin_mut, Stream, StreamExt};
 use ruma::{RoomId, UserId};
 
 use crate::{globals, rooms, rooms::short::ShortStateHash, Dep};
@@ -22,7 +21,6 @@ struct Data {
 struct Services {
 	globals: Dep<globals::Service>,
 	short: Dep<rooms::short::Service>,
-	state_cache: Dep<rooms::state_cache::Service>,
 }
 
 impl crate::Service for Service {
@@ -38,7 +36,6 @@ impl crate::Service for Service {
 			services: Services {
 				globals: args.depend::<globals::Service>("globals"),
 				short: args.depend::<rooms::short::Service>("rooms::short"),
-				state_cache: args.depend::<rooms::state_cache::Service>("rooms::state_cache"),
 			},
 		}))
 	}
@@ -118,22 +115,3 @@ pub async fn get_token_shortstatehash(&self, room_id: &RoomId, token: u64) -> Re
 		.await
 		.deserialized()
 }
-
-#[implement(Service)]
-pub async fn has_shared_rooms<'a>(&'a self, user_a: &'a UserId, user_b: &'a UserId) -> bool {
-	let get_shared_rooms = self.get_shared_rooms(user_a, user_b);
-
-	pin_mut!(get_shared_rooms);
-	get_shared_rooms.next().await.is_some()
-}
-
-//TODO: optimize; replace point-queries with dual iteration
-#[implement(Service)]
-pub fn get_shared_rooms<'a>(
-	&'a self, user_a: &'a UserId, user_b: &'a UserId,
-) -> impl Stream<Item = &RoomId> + Send + 'a {
-	self.services
-		.state_cache
-		.rooms_joined(user_a)
-		.filter(|room_id| self.services.state_cache.is_joined(user_b, room_id))
-}