feat: lazy loading

src/client_server/context.rs

@@ -1,5 +1,9 @@
 use crate::{database::DatabaseGuard, ConduitResult, Error, Ruma};
-use ruma::api::client::{error::ErrorKind, r0::context::get_context};
+use ruma::{
+    api::client::{error::ErrorKind, r0::context::get_context},
+    events::EventType,
+};
+use std::collections::HashSet;
 use std::convert::TryFrom;
 
 #[cfg(feature = "conduit_bin")]
@@ -21,6 +25,7 @@ pub async fn get_context_route(
     body: Ruma<get_context::Request<'_>>,
 ) -> ConduitResult<get_context::Response> {
     let sender_user = body.sender_user.as_ref().expect("user is authenticated");
+    let sender_device = body.sender_device.as_ref().expect("user is authenticated");
 
     if !db.rooms.is_joined(sender_user, &body.room_id)? {
         return Err(Error::BadRequest(
@@ -29,6 +34,8 @@ pub async fn get_context_route(
         ));
     }
 
+    let mut lazy_loaded = HashSet::new();
+
     let base_pdu_id = db
         .rooms
         .get_pdu_id(&body.event_id)?
@@ -45,8 +52,18 @@ pub async fn get_context_route(
         .ok_or(Error::BadRequest(
             ErrorKind::NotFound,
             "Base event not found.",
-        ))?
+        ))?;
-        .to_room_event();
+
+    if !db.rooms.lazy_load_was_sent_before(
+        &sender_user,
+        &sender_device,
+        &body.room_id,
+        &base_event.sender,
+    )? {
+        lazy_loaded.insert(base_event.sender.clone());
+    }
+
+    let base_event = base_event.to_room_event();
 
     let events_before: Vec<_> = db
         .rooms
@@ -60,6 +77,17 @@ pub async fn get_context_route(
         .filter_map(|r| r.ok()) // Remove buggy events
         .collect();
 
+    for (_, event) in &events_before {
+        if !db.rooms.lazy_load_was_sent_before(
+            &sender_user,
+            &sender_device,
+            &body.room_id,
+            &event.sender,
+        )? {
+            lazy_loaded.insert(event.sender.clone());
+        }
+    }
+
     let start_token = events_before
         .last()
         .and_then(|(pdu_id, _)| db.rooms.pdu_count(pdu_id).ok())
@@ -82,6 +110,17 @@ pub async fn get_context_route(
         .filter_map(|r| r.ok()) // Remove buggy events
         .collect();
 
+    for (_, event) in &events_after {
+        if !db.rooms.lazy_load_was_sent_before(
+            &sender_user,
+            &sender_device,
+            &body.room_id,
+            &event.sender,
+        )? {
+            lazy_loaded.insert(event.sender.clone());
+        }
+    }
+
     let end_token = events_after
         .last()
         .and_then(|(pdu_id, _)| db.rooms.pdu_count(pdu_id).ok())
@@ -92,18 +131,23 @@ pub async fn get_context_route(
         .map(|(_, pdu)| pdu.to_room_event())
         .collect();
 
+    let mut state = Vec::new();
+    for ll_id in &lazy_loaded {
+        if let Some(member_event) =
+            db.rooms
+                .room_state_get(&body.room_id, &EventType::RoomMember, ll_id.as_str())?
+        {
+            state.push(member_event.to_state_event());
+        }
+    }
+
     let resp = get_context::Response {
         start: start_token,
         end: end_token,
         events_before,
         event: Some(base_event),
         events_after,
-        state: db // TODO: State at event
+        state,
-            .rooms
-            .room_state_full(&body.room_id)?
-            .values()
-            .map(|pdu| pdu.to_state_event())
-            .collect(),
     };
 
     Ok(resp.into())

src/client_server/message.rs

@@ -6,7 +6,11 @@ use ruma::{
     },
     events::EventType,
 };
-use std::{collections::BTreeMap, convert::TryInto, sync::Arc};
+use std::{
+    collections::{BTreeMap, HashSet},
+    convert::TryInto,
+    sync::Arc,
+};
 
 #[cfg(feature = "conduit_bin")]
 use rocket::{get, put};
@@ -117,6 +121,7 @@ pub async fn get_message_events_route(
     body: Ruma<get_message_events::Request<'_>>,
 ) -> ConduitResult<get_message_events::Response> {
     let sender_user = body.sender_user.as_ref().expect("user is authenticated");
+    let sender_device = body.sender_device.as_ref().expect("user is authenticated");
 
     if !db.rooms.is_joined(sender_user, &body.room_id)? {
         return Err(Error::BadRequest(
@@ -136,6 +141,12 @@ pub async fn get_message_events_route(
     // Use limit or else 10
     let limit = body.limit.try_into().map_or(10_usize, |l: u32| l as usize);
 
+    let next_token;
+
+    let mut resp = get_message_events::Response::new();
+
+    let mut lazy_loaded = HashSet::new();
+
     match body.dir {
         get_message_events::Direction::Forward => {
             let events_after: Vec<_> = db
@@ -152,21 +163,27 @@ pub async fn get_message_events_route(
                 .take_while(|&(k, _)| Some(Ok(k)) != to) // Stop at `to`
                 .collect();
 
-            let end_token = events_after.last().map(|(count, _)| count.to_string());
+            for (_, event) in &events_after {
+                if !db.rooms.lazy_load_was_sent_before(
+                    &sender_user,
+                    &sender_device,
+                    &body.room_id,
+                    &event.sender,
+                )? {
+                    lazy_loaded.insert(event.sender.clone());
+                }
+            }
+
+            next_token = events_after.last().map(|(count, _)| count).copied();
 
             let events_after: Vec<_> = events_after
                 .into_iter()
                 .map(|(_, pdu)| pdu.to_room_event())
                 .collect();
 
-            let resp = get_message_events::Response {
+            resp.start = body.from.to_owned();
-                start: body.from.to_owned(),
+            resp.end = next_token.map(|count| count.to_string());
-                end: end_token,
+            resp.chunk = events_after;
-                chunk: events_after,
-                state: Vec::new(),
-            };
-
-            Ok(resp.into())
         }
         get_message_events::Direction::Backward => {
             let events_before: Vec<_> = db
@@ -183,21 +200,51 @@ pub async fn get_message_events_route(
                 .take_while(|&(k, _)| Some(Ok(k)) != to) // Stop at `to`
                 .collect();
 
-            let start_token = events_before.last().map(|(count, _)| count.to_string());
+            for (_, event) in &events_before {
+                if !db.rooms.lazy_load_was_sent_before(
+                    &sender_user,
+                    &sender_device,
+                    &body.room_id,
+                    &event.sender,
+                )? {
+                    lazy_loaded.insert(event.sender.clone());
+                }
+            }
+
+            next_token = events_before.last().map(|(count, _)| count).copied();
 
             let events_before: Vec<_> = events_before
                 .into_iter()
                 .map(|(_, pdu)| pdu.to_room_event())
                 .collect();
 
-            let resp = get_message_events::Response {
+            resp.start = body.from.to_owned();
-                start: body.from.to_owned(),
+            resp.end = next_token.map(|count| count.to_string());
-                end: start_token,
+            resp.chunk = events_before;
-                chunk: events_before,
+        }
-                state: Vec::new(),
+    }
-            };
+
+    db.rooms
+        .lazy_load_confirm_delivery(&sender_user, &sender_device, &body.room_id, from)?;
+    resp.state = Vec::new();
+    for ll_id in &lazy_loaded {
+        if let Some(member_event) =
+            db.rooms
+                .room_state_get(&body.room_id, &EventType::RoomMember, ll_id.as_str())?
+        {
+            resp.state.push(member_event.to_state_event());
+        }
+    }
+
+    if let Some(next_token) = next_token {
+        db.rooms.lazy_load_mark_sent(
+            &sender_user,
+            &sender_device,
+            &body.room_id,
+            lazy_loaded.into_iter().collect(),
+            next_token,
+        );
+    }
 
     Ok(resp.into())
-        }
-    }
 }

src/client_server/sync.rs

@@ -264,6 +264,14 @@ async fn sync_helper(
         // limited unless there are events in non_timeline_pdus
         let limited = non_timeline_pdus.next().is_some();
 
+        let mut timeline_users = HashSet::new();
+        for (_, event) in &timeline_pdus {
+            timeline_users.insert(event.sender.as_str().to_owned());
+        }
+
+        db.rooms
+            .lazy_load_confirm_delivery(&sender_user, &sender_device, &room_id, since)?;
+
         // Database queries:
 
         let current_shortstatehash = db
@@ -344,14 +352,51 @@ async fn sync_helper(
             state_events,
         ) = if since_shortstatehash.is_none() {
             // Probably since = 0, we will do an initial sync
+
             let (joined_member_count, invited_member_count, heroes) = calculate_counts()?;
 
             let current_state_ids = db.rooms.state_full_ids(current_shortstatehash)?;
-            let state_events: Vec<_> = current_state_ids
+
-                .iter()
+            let mut state_events = Vec::new();
-                .map(|(_, id)| db.rooms.get_pdu(id))
+            let mut lazy_loaded = Vec::new();
-                .filter_map(|r| r.ok().flatten())
+
-                .collect();
+            for (_, id) in current_state_ids {
+                let pdu = match db.rooms.get_pdu(&id)? {
+                    Some(pdu) => pdu,
+                    None => {
+                        error!("Pdu in state not found: {}", id);
+                        continue;
+                    }
+                };
+                let state_key = pdu
+                    .state_key
+                    .as_ref()
+                    .expect("state events have state keys");
+                if pdu.kind != EventType::RoomMember {
+                    state_events.push(pdu);
+                } else if full_state || timeline_users.contains(state_key) {
+                    // TODO: check filter: is ll enabled?
+                    lazy_loaded.push(
+                        UserId::parse(state_key.as_ref())
+                            .expect("they are in timeline_users, so they should be correct"),
+                    );
+                    state_events.push(pdu);
+                }
+            }
+
+            // Reset lazy loading because this is an initial sync
+            db.rooms
+                .lazy_load_reset(&sender_user, &sender_device, &room_id)?;
+
+            // The state_events above should contain all timeline_users, let's mark them as lazy
+            // loaded.
+            db.rooms.lazy_load_mark_sent(
+                &sender_user,
+                &sender_device,
+                &room_id,
+                lazy_loaded,
+                next_batch,
+            );
 
             (
                 heroes,
@@ -387,21 +432,67 @@ async fn sync_helper(
 
             let since_state_ids = db.rooms.state_full_ids(since_shortstatehash)?;
 
-            let state_events = if joined_since_last_sync {
+            /*
+            let state_events = if joined_since_last_sync || full_state {
                 current_state_ids
                     .iter()
                     .map(|(_, id)| db.rooms.get_pdu(id))
                     .filter_map(|r| r.ok().flatten())
                     .collect::<Vec<_>>()
             } else {
-                current_state_ids
+                */
-                    .iter()
+            let mut state_events = Vec::new();
-                    .filter(|(key, id)| since_state_ids.get(key) != Some(id))
+            let mut lazy_loaded = Vec::new();
-                    .map(|(_, id)| db.rooms.get_pdu(id))
+
-                    .filter_map(|r| r.ok().flatten())
+            for (key, id) in current_state_ids {
-                    .collect()
+                let pdu = match db.rooms.get_pdu(&id)? {
+                    Some(pdu) => pdu,
+                    None => {
+                        error!("Pdu in state not found: {}", id);
+                        continue;
+                    }
                 };
 
+                let state_key = pdu
+                    .state_key
+                    .as_ref()
+                    .expect("state events have state keys");
+
+                if pdu.kind != EventType::RoomMember {
+                    if full_state || since_state_ids.get(&key) != Some(&id) {
+                        state_events.push(pdu);
+                    }
+                    continue;
+                }
+
+                // Pdu has to be a member event
+                let state_key_userid = UserId::parse(state_key.as_ref())
+                    .expect("they are in timeline_users, so they should be correct");
+
+                if full_state || since_state_ids.get(&key) != Some(&id) {
+                    lazy_loaded.push(state_key_userid);
+                    state_events.push(pdu);
+                } else if timeline_users.contains(state_key)
+                    && !db.rooms.lazy_load_was_sent_before(
+                        &sender_user,
+                        &sender_device,
+                        &room_id,
+                        &state_key_userid,
+                    )?
+                {
+                    lazy_loaded.push(state_key_userid);
+                    state_events.push(pdu);
+                }
+            }
+
+            db.rooms.lazy_load_mark_sent(
+                &sender_user,
+                &sender_device,
+                &room_id,
+                lazy_loaded,
+                next_batch,
+            );
+
             let encrypted_room = db
                 .rooms
                 .state_get(current_shortstatehash, &EventType::RoomEncryption, "")?

src/database.rs

@@ -288,6 +288,8 @@ impl Database {
                 userroomid_leftstate: builder.open_tree("userroomid_leftstate")?,
                 roomuserid_leftcount: builder.open_tree("roomuserid_leftcount")?,
 
+                lazyloadedids: builder.open_tree("lazyloadedids")?,
+
                 userroomid_notificationcount: builder.open_tree("userroomid_notificationcount")?,
                 userroomid_highlightcount: builder.open_tree("userroomid_highlightcount")?,
 
@@ -323,6 +325,7 @@ impl Database {
                 statekeyshort_cache: Mutex::new(LruCache::new(1_000_000)),
                 our_real_users_cache: RwLock::new(HashMap::new()),
                 appservice_in_room_cache: RwLock::new(HashMap::new()),
+                lazy_load_waiting: Mutex::new(HashMap::new()),
                 stateinfo_cache: Mutex::new(LruCache::new(1000)),
             },
             account_data: account_data::AccountData {

src/database/rooms.rs

@@ -28,7 +28,7 @@ use ruma::{
     push::{Action, Ruleset, Tweak},
     serde::{CanonicalJsonObject, CanonicalJsonValue, Raw},
     state_res::{self, RoomVersion, StateMap},
-    uint, EventId, RoomAliasId, RoomId, RoomVersionId, ServerName, UserId,
+    uint, DeviceId, EventId, RoomAliasId, RoomId, RoomVersionId, ServerName, UserId,
 };
 use serde::Deserialize;
 use serde_json::value::to_raw_value;
@@ -79,6 +79,8 @@ pub struct Rooms {
     pub(super) userroomid_leftstate: Arc<dyn Tree>,
     pub(super) roomuserid_leftcount: Arc<dyn Tree>,
 
+    pub(super) lazyloadedids: Arc<dyn Tree>, // LazyLoadedIds = UserId + DeviceId + RoomId + LazyLoadedUserId
+
     pub(super) userroomid_notificationcount: Arc<dyn Tree>, // NotifyCount = u64
     pub(super) userroomid_highlightcount: Arc<dyn Tree>,    // HightlightCount = u64
 
@@ -117,6 +119,8 @@ pub struct Rooms {
     pub(super) shortstatekey_cache: Mutex<LruCache<u64, (EventType, String)>>,
     pub(super) our_real_users_cache: RwLock<HashMap<Box<RoomId>, Arc<HashSet<Box<UserId>>>>>,
     pub(super) appservice_in_room_cache: RwLock<HashMap<Box<RoomId>, HashMap<String, bool>>>,
+    pub(super) lazy_load_waiting:
+        Mutex<HashMap<(Box<UserId>, Box<DeviceId>, Box<RoomId>, u64), Vec<Box<UserId>>>>,
     pub(super) stateinfo_cache: Mutex<
         LruCache<
             u64,
@@ -3466,4 +3470,94 @@ impl Rooms {
 
         Ok(())
     }
+
+    #[tracing::instrument(skip(self))]
+    pub fn lazy_load_was_sent_before(
+        &self,
+        user_id: &UserId,
+        device_id: &DeviceId,
+        room_id: &RoomId,
+        ll_user: &UserId,
+    ) -> Result<bool> {
+        let mut key = user_id.as_bytes().to_vec();
+        key.push(0xff);
+        key.extend_from_slice(&device_id.as_bytes());
+        key.push(0xff);
+        key.extend_from_slice(&room_id.as_bytes());
+        key.push(0xff);
+        key.extend_from_slice(&ll_user.as_bytes());
+        Ok(self.lazyloadedids.get(&key)?.is_some())
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn lazy_load_mark_sent(
+        &self,
+        user_id: &UserId,
+        device_id: &DeviceId,
+        room_id: &RoomId,
+        lazy_load: Vec<Box<UserId>>,
+        count: u64,
+    ) {
+        self.lazy_load_waiting.lock().unwrap().insert(
+            (
+                user_id.to_owned(),
+                device_id.to_owned(),
+                room_id.to_owned(),
+                count,
+            ),
+            lazy_load,
+        );
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn lazy_load_confirm_delivery(
+        &self,
+        user_id: &UserId,
+        device_id: &DeviceId,
+        room_id: &RoomId,
+        since: u64,
+    ) -> Result<()> {
+        if let Some(user_ids) = self.lazy_load_waiting.lock().unwrap().remove(&(
+            user_id.to_owned(),
+            device_id.to_owned(),
+            room_id.to_owned(),
+            since,
+        )) {
+            let mut prefix = user_id.as_bytes().to_vec();
+            prefix.push(0xff);
+            prefix.extend_from_slice(&device_id.as_bytes());
+            prefix.push(0xff);
+            prefix.extend_from_slice(&room_id.as_bytes());
+            prefix.push(0xff);
+
+            for ll_id in user_ids {
+                let mut key = prefix.clone();
+                key.extend_from_slice(&ll_id.as_bytes());
+                self.lazyloadedids.insert(&key, &[])?;
+            }
+        }
+
+        Ok(())
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub fn lazy_load_reset(
+        &self,
+        user_id: &Box<UserId>,
+        device_id: &Box<DeviceId>,
+        room_id: &Box<RoomId>,
+    ) -> Result<()> {
+        let mut prefix = user_id.as_bytes().to_vec();
+        prefix.push(0xff);
+        prefix.extend_from_slice(&device_id.as_bytes());
+        prefix.push(0xff);
+        prefix.extend_from_slice(&room_id.as_bytes());
+        prefix.push(0xff);
+
+        for (key, _) in self.lazyloadedids.scan_prefix(prefix) {
+            self.lazyloadedids.remove(&key)?;
+        }
+
+        Ok(())
+    }
 }