feat: unstable support for msc4125

Cargo.lock

@@ -392,6 +392,7 @@ dependencies = [
  "http",
  "hyper",
  "image",
+ "itertools 0.12.1",
  "jsonwebtoken",
  "lazy_static",
  "lru-cache",

Cargo.toml

@@ -112,6 +112,9 @@ tikv-jemallocator = { version = "0.5.0", features = ["unprefixed_malloc_on_suppo
 lazy_static = "1.4.0"
 async-trait = "0.1.68"
 
+# Used to make working with iterators easier, was already a transitive depdendency
+itertools = "0.12"
+
 sd-notify = { version = "0.4.1", optional = true }
 
 [dependencies.rocksdb]

src/api/client_server/membership.rs

@@ -52,6 +52,11 @@ pub async fn join_room_by_id_route(
 
     let mut servers = Vec::new(); // There is no body.server_name for /roomId/join
     servers.extend(
+        services()
+            .rooms
+            .state_cache
+            .servers_invite_via(&body.room_id)?
+            .unwrap_or(
                 services()
                     .rooms
                     .state_cache
@@ -62,7 +67,9 @@ pub async fn join_room_by_id_route(
                     .filter_map(|event: serde_json::Value| event.get("sender").cloned())
                     .filter_map(|sender| sender.as_str().map(|s| s.to_owned()))
                     .filter_map(|sender| UserId::parse(sender).ok())
-            .map(|user| user.server_name().to_owned()),
+                    .map(|user| user.server_name().to_owned())
+                    .collect(),
+            ),
     );
 
     servers.push(
@@ -98,6 +105,11 @@ pub async fn join_room_by_id_or_alias_route(
         Ok(room_id) => {
             let mut servers = body.server_name.clone();
             servers.extend(
+                services()
+                    .rooms
+                    .state_cache
+                    .servers_invite_via(&room_id)?
+                    .unwrap_or(
                         services()
                             .rooms
                             .state_cache
@@ -108,7 +120,9 @@ pub async fn join_room_by_id_or_alias_route(
                             .filter_map(|event: serde_json::Value| event.get("sender").cloned())
                             .filter_map(|sender| sender.as_str().map(|s| s.to_owned()))
                             .filter_map(|sender| UserId::parse(sender).ok())
-                    .map(|user| user.server_name().to_owned()),
+                            .map(|user| user.server_name().to_owned())
+                            .collect(),
+                    ),
             );
 
             servers.push(
@@ -1261,6 +1275,7 @@ pub(crate) async fn invite_helper<'a>(
                     room_version: room_version_id.clone(),
                     event: PduEvent::convert_to_outgoing_federation_event(pdu_json.clone()),
                     invite_room_state,
+                    via: services().rooms.state_cache.servers_route_via(room_id).ok(),
                 },
             )
             .await?;
@@ -1423,6 +1438,7 @@ pub async fn leave_room(user_id: &UserId, room_id: &RoomId, reason: Option<Strin
             MembershipState::Leave,
             user_id,
             last_state,
+            None,
             true,
         )?;
     } else {
@@ -1454,6 +1470,7 @@ pub async fn leave_room(user_id: &UserId, room_id: &RoomId, reason: Option<Strin
                     MembershipState::Leave,
                     user_id,
                     None,
+                    None,
                     true,
                 )?;
                 return Ok(());
@@ -1503,14 +1520,21 @@ async fn remote_leave_room(user_id: &UserId, room_id: &RoomId) -> Result<()> {
             "User is not invited.",
         ))?;
 
-    let servers: HashSet<_> = invite_state
+    let servers: HashSet<_> = services()
+        .rooms
+        .state_cache
+        .servers_invite_via(&room_id)?
+        .map(|servers| HashSet::from_iter(servers))
+        .unwrap_or(
+            invite_state
                 .iter()
                 .filter_map(|event| serde_json::from_str(event.json().get()).ok())
                 .filter_map(|event: serde_json::Value| event.get("sender").cloned())
                 .filter_map(|sender| sender.as_str().map(|s| s.to_owned()))
                 .filter_map(|sender| UserId::parse(sender).ok())
                 .map(|user| user.server_name().to_owned())
-        .collect();
+                .collect(),
+        );
 
     for remote_server in servers {
         let make_leave_response = services()

src/api/server_server.rs

@@ -1669,6 +1669,15 @@ pub async fn create_invite_route(
         ));
     }
 
+    if let Some(via) = &body.via {
+        if via.is_empty() {
+            return Err(Error::BadRequest(
+                ErrorKind::InvalidParam,
+                "via field must not be empty.",
+            ));
+        }
+    }
+
     let mut signed_event = utils::to_canonical_object(&body.event)
         .map_err(|_| Error::BadRequest(ErrorKind::InvalidParam, "Invite event is invalid."))?;
 
@@ -1744,6 +1753,7 @@ pub async fn create_invite_route(
             MembershipState::Invite,
             &sender,
             Some(invite_state),
+            body.via,
             true,
         )?;
     }

src/database/key_value/rooms/state_cache.rs

@@ -1,5 +1,6 @@
 use std::{collections::HashSet, sync::Arc};
 
+use itertools::Itertools;
 use ruma::{
     events::{AnyStrippedStateEvent, AnySyncStateEvent},
     serde::Raw,
@@ -21,7 +22,11 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
     }
 
     fn mark_as_joined(&self, user_id: &UserId, room_id: &RoomId) -> Result<()> {
-        let mut roomuser_id = room_id.as_bytes().to_vec();
+        let roomid = room_id.as_bytes().to_vec();
+        let mut roomid_prefix = room_id.as_bytes().to_vec();
+        roomid_prefix.push(0xff);
+
+        let mut roomuser_id = roomid_prefix.clone();
         roomuser_id.push(0xff);
         roomuser_id.extend_from_slice(user_id.as_bytes());
 
@@ -36,6 +41,16 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         self.userroomid_leftstate.remove(&userroom_id)?;
         self.roomuserid_leftcount.remove(&roomuser_id)?;
 
+        if self.roomuserid_joined.scan_prefix(roomid_prefix).count() == 0
+            && self
+                .roomuserid_invitecount
+                .scan_prefix(roomid_prefix)
+                .count()
+                == 0
+        {
+            self.roomid_inviteviaservers.remove(&roomid)?;
+        }
+
         Ok(())
     }
 
@@ -44,6 +59,7 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         user_id: &UserId,
         room_id: &RoomId,
         last_state: Option<Vec<Raw<AnyStrippedStateEvent>>>,
+        invite_via: Option<Vec<OwnedServerName>>,
     ) -> Result<()> {
         let mut roomuser_id = room_id.as_bytes().to_vec();
         roomuser_id.push(0xff);
@@ -67,12 +83,30 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         self.userroomid_leftstate.remove(&userroom_id)?;
         self.roomuserid_leftcount.remove(&roomuser_id)?;
 
+        if let Some(servers) = invite_via {
+            let mut prev_servers = self.servers_invite_via(room_id)?.unwrap_or(Vec::new());
+            prev_servers.append(&mut servers);
+            let servers = prev_servers.iter().rev().unique().rev().collect_vec();
+
+            let servers = servers
+                .iter()
+                .map(|server| server.as_bytes())
+                .collect_vec()
+                .join(&[0xff][..]);
+
+            self.roomid_inviteviaservers
+                .insert(&room_id.as_bytes().to_vec(), &servers)?;
+        }
+
         Ok(())
     }
 
     fn mark_as_left(&self, user_id: &UserId, room_id: &RoomId) -> Result<()> {
-        let mut roomuser_id = room_id.as_bytes().to_vec();
+        let roomid = room_id.as_bytes().to_vec();
-        roomuser_id.push(0xff);
+        let mut roomid_prefix = room_id.as_bytes().to_vec();
+        roomid_prefix.push(0xff);
+
+        let mut roomuser_id = roomid_prefix.clone();
         roomuser_id.extend_from_slice(user_id.as_bytes());
 
         let mut userroom_id = user_id.as_bytes().to_vec();
@@ -92,6 +126,16 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
         self.userroomid_invitestate.remove(&userroom_id)?;
         self.roomuserid_invitecount.remove(&roomuser_id)?;
 
+        if self.roomuserid_joined.scan_prefix(roomid_prefix).count() == 0
+            && self
+                .roomuserid_invitecount
+                .scan_prefix(roomid_prefix)
+                .count()
+                == 0
+        {
+            self.roomid_inviteviaservers.remove(&roomid)?;
+        }
+
         Ok(())
     }
 
@@ -604,4 +648,41 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
 
         Ok(self.userroomid_leftstate.get(&userroom_id)?.is_some())
     }
+
+    #[tracing::instrument(skip(self))]
+    fn servers_invite_via(&self, room_id: &RoomId) -> Result<Option<Vec<OwnedServerName>>> {
+        let room_id = room_id.as_bytes().to_vec();
+
+        self.roomid_inviteviaservers
+            .get(&room_id)?
+            .map(|servers| {
+                let state = serde_json::from_slice(&servers)
+                    .map_err(|_| Error::bad_database("Invalid state in userroomid_leftstate."))?;
+
+                Ok(state)
+            })
+            .transpose()
+    }
+
+    #[tracing::instrument(skip(self))]
+    fn add_servers_invite_via(
+        &self,
+        room_id: &RoomId,
+        servers: &Vec<OwnedServerName>,
+    ) -> Result<()> {
+        let mut prev_servers = self.servers_invite_via(room_id)?.unwrap_or(Vec::new());
+        prev_servers.append(&mut servers);
+        let servers = prev_servers.iter().rev().unique().rev().collect_vec();
+
+        let servers = servers
+            .iter()
+            .map(|server| server.as_bytes())
+            .collect_vec()
+            .join(&[0xff][..]);
+
+        self.roomid_inviteviaservers
+            .insert(&room_id.as_bytes().to_vec(), &servers)?;
+
+        Ok(())
+    }
 }

src/database/mod.rs

@@ -161,6 +161,8 @@ pub struct KeyValueDatabase {
     //pub pusher: pusher::PushData,
     pub(super) senderkey_pusher: Arc<dyn KvTree>,
 
+    pub(super) roomid_inviteviaservers: Arc<dyn KvTree>,
+
     pub(super) pdu_cache: Mutex<LruCache<OwnedEventId, Arc<PduEvent>>>,
     pub(super) shorteventid_cache: Mutex<LruCache<u64, Arc<EventId>>>,
     pub(super) auth_chain_cache: Mutex<LruCache<Vec<u64>, Arc<HashSet<u64>>>>,
@@ -368,6 +370,8 @@ impl KeyValueDatabase {
             global: builder.open_tree("global")?,
             server_signingkeys: builder.open_tree("server_signingkeys")?,
 
+            roomid_inviteviaservers: builder.open_tree("roomid_inviteviaservers")?,
+
             pdu_cache: Mutex::new(LruCache::new(
                 config
                     .pdu_cache_capacity

src/service/rooms/state/mod.rs

@@ -86,6 +86,7 @@ impl Service {
                         membership,
                         &pdu.sender,
                         None,
+                        None,
                         false,
                     )?;
                 }

src/service/rooms/state_cache/data.rs

@@ -15,6 +15,7 @@ pub trait Data: Send + Sync {
         user_id: &UserId,
         room_id: &RoomId,
         last_state: Option<Vec<Raw<AnyStrippedStateEvent>>>,
+        invite_via: Option<Vec<OwnedServerName>>,
     ) -> Result<()>;
     fn mark_as_left(&self, user_id: &UserId, room_id: &RoomId) -> Result<()>;
 
@@ -106,4 +107,14 @@ pub trait Data: Send + Sync {
     fn is_invited(&self, user_id: &UserId, room_id: &RoomId) -> Result<bool>;
 
     fn is_left(&self, user_id: &UserId, room_id: &RoomId) -> Result<bool>;
+
+    /// Gets the servers to either accept or decline invites via for a given room.
+    fn servers_invite_via(&self, room_id: &RoomId) -> Result<Option<Vec<OwnedServerName>>>;
+
+    /// Add the given servers the list to accept or decline invites via for a given room.
+    fn add_servers_invite_via(
+        &self,
+        room_id: &RoomId,
+        servers: &Vec<OwnedServerName>,
+    ) -> Result<()>;
 }

src/service/rooms/state_cache/mod.rs

@@ -3,14 +3,19 @@ use std::{collections::HashSet, sync::Arc};
 
 pub use data::Data;
 
+use itertools::Itertools;
 use ruma::{
     events::{
         direct::DirectEvent,
         ignored_user_list::IgnoredUserListEvent,
-        room::{create::RoomCreateEventContent, member::MembershipState},
+        room::{
+            create::RoomCreateEventContent, member::MembershipState,
+            power_levels::RoomPowerLevelsEventContent,
+        },
         AnyStrippedStateEvent, AnySyncStateEvent, GlobalAccountDataEventType,
         RoomAccountDataEventType, StateEventType,
     },
+    int,
     serde::Raw,
     OwnedRoomId, OwnedServerName, OwnedUserId, RoomId, ServerName, UserId,
 };
@@ -32,6 +37,7 @@ impl Service {
         membership: MembershipState,
         sender: &UserId,
         last_state: Option<Vec<Raw<AnyStrippedStateEvent>>>,
+        invite_via: Option<Vec<OwnedServerName>>,
         update_joined_count: bool,
     ) -> Result<()> {
         // Keep track what remote users exist by adding them as "deactivated" users
@@ -176,7 +182,8 @@ impl Service {
                     return Ok(());
                 }
 
-                self.db.mark_as_invited(user_id, room_id, last_state)?;
+                self.db
+                    .mark_as_invited(user_id, room_id, last_state, invite_via)?;
             }
             MembershipState::Leave | MembershipState::Ban => {
                 self.db.mark_as_left(user_id, room_id)?;
@@ -350,4 +357,54 @@ impl Service {
     pub fn is_left(&self, user_id: &UserId, room_id: &RoomId) -> Result<bool> {
         self.db.is_left(user_id, room_id)
     }
+
+    #[tracing::instrument(skip(self))]
+    pub fn servers_invite_via(&self, room_id: &RoomId) -> Result<Option<Vec<OwnedServerName>>> {
+        self.db.servers_invite_via(room_id)
+    }
+
+    /// Gets up to three servers that are likely to be in the room in the distant future.
+    ///
+    /// See https://spec.matrix.org/v1.10/appendices/#routing
+    #[tracing::instrument(skip(self))]
+    pub fn servers_route_via(&self, room_id: &RoomId) -> Result<Vec<OwnedServerName>> {
+        let most_powerful_user_server = services()
+            .rooms
+            .state_accessor
+            .room_state_get(room_id, &StateEventType::RoomPowerLevels, "")?
+            .map(|pdu| {
+                serde_json::from_str(pdu.content.get()).map(
+                    |conent: RoomPowerLevelsEventContent| {
+                        conent
+                            .users
+                            .iter()
+                            .max_by_key(|(_, power)| power)
+                            .and_then(|x| if x.1 >= &int!(50) { Some(x) } else { None })
+                            .map(|(user, power)| user.server_name().to_owned())
+                    },
+                )
+            })
+            .transpose()
+            .map_err(|e| Error::bad_database("Invalid power levels event content in database"))?
+            .flatten();
+
+        let mut servers = services()
+            .rooms
+            .state_cache
+            .room_members(room_id)
+            .filter_map(Result::ok)
+            .counts_by(|user| user.server_name())
+            .iter()
+            .sorted_by_key(|(_, users)| users)
+            .map(|(server, _)| server.to_owned().to_owned())
+            .rev()
+            .take(3)
+            .collect_vec();
+
+        if let Some(server) = most_powerful_user_server {
+            servers.insert(0, server);
+            servers.truncate(3);
+        }
+        Ok(servers)
+    }
 }

src/service/rooms/timeline/mod.rs

@@ -427,6 +427,7 @@ impl Service {
                         content.membership,
                         &pdu.sender,
                         invite_state,
+                        None,
                         true,
                     )?;
                 }