matrix-rust-sdk

// Copyright 2023 The Matrix.org Foundation C.I.C.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//! The SDK's representation of the result of a `/sync` request.

use std::{

    collections::{BTreeMap, btree_map},

    fmt,

    time::Duration,

};

pub use matrix_sdk_base::sync::*;

use matrix_sdk_base::{

    debug::{

        DebugInvitedRoom, DebugKnockedRoom, DebugListOfProcessedToDeviceEvents,

        DebugListOfRawEventsNoId,

    },

    sleep::sleep,

    sync::SyncResponse as BaseSyncResponse,

    timer,

};

use matrix_sdk_common::deserialized_responses::ProcessedToDeviceEvent;

use ruma::{

    OwnedRoomId, RoomId,

    api::client::sync::sync_events::{

        self,

        v3::{InvitedRoom, KnockedRoom},

    },

    events::{AnyGlobalAccountDataEvent, presence::PresenceEvent},

    serde::Raw,

    time::Instant,

};

use tracing::{debug, error, instrument, warn};

use crate::{Client, Result, Room, event_handler::HandlerKind};

/// The processed response of a `/sync` request.

#[derive(Clone, Default)]

pub struct SyncResponse {

    /// The batch token to supply in the `since` param of the next `/sync`

    /// request.

    pub next_batch: String,

    /// Updates to rooms.

    pub rooms: RoomUpdates,

    /// Updates to the presence status of other users.

    pub presence: Vec<Raw<PresenceEvent>>,

    /// The global private data created by this user.

    pub account_data: Vec<Raw<AnyGlobalAccountDataEvent>>,

    /// Messages sent directly between devices.

    pub to_device: Vec<ProcessedToDeviceEvent>,

    /// New notifications per room.

    pub notifications: BTreeMap<OwnedRoomId, Vec<Notification>>,

}

impl SyncResponse {

    pub(crate) fn new(next_batch: String, base_response: BaseSyncResponse) -> Self {

        let BaseSyncResponse { rooms, presence, account_data, to_device, notifications } =

            base_response;

        Self { next_batch, rooms, presence, account_data, to_device, notifications }

    }

}

#[cfg(not(tarpaulin_include))]

impl fmt::Debug for SyncResponse {

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

        f.debug_struct("SyncResponse")

            .field("next_batch", &self.next_batch)

            .field("rooms", &self.rooms)

            .field("account_data", &DebugListOfRawEventsNoId(&self.account_data))

            .field("to_device", &DebugListOfProcessedToDeviceEvents(&self.to_device))

            .field("notifications", &self.notifications)

            .finish_non_exhaustive()

    }

}

/// A batch of updates to a room.

#[derive(Clone)]

pub enum RoomUpdate {

    /// Updates to a room the user is no longer in.

    Left {

        /// Room object with general information on the room.

        room: Room,

        /// Updates to the room.

        updates: LeftRoomUpdate,

    },

    /// Updates to a room the user is currently in.

    Joined {

        /// Room object with general information on the room.

        room: Room,

        /// Updates to the room.

        updates: JoinedRoomUpdate,

    },

    /// Updates to a room the user is invited to.

    Invited {

        /// Room object with general information on the room.

        room: Room,

        /// Updates to the room.

        updates: InvitedRoom,

    },

    /// Updates to a room the user knocked on.

    Knocked {

        /// Room object with general information on the room.

        room: Room,

        /// Updates to the room.

        updates: KnockedRoom,

    },

}

#[cfg(not(tarpaulin_include))]

impl fmt::Debug for RoomUpdate {

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

        match self {

            Self::Left { room, updates } => {

                f.debug_struct("Left").field("room", room).field("updates", updates).finish()

            }

            Self::Joined { room, updates } => {

                f.debug_struct("Joined").field("room", room).field("updates", updates).finish()

            }

            Self::Invited { room, updates } => f

                .debug_struct("Invited")

                .field("room", room)

                .field("updates", &DebugInvitedRoom(updates))

                .finish(),

            Self::Knocked { room, updates } => f

                .debug_struct("Knocked")

                .field("room", room)

                .field("updates", &DebugKnockedRoom(updates))

                .finish(),

        }

    }

}

/// Internal functionality related to getting events from the server

/// (`sync_events` endpoint)

impl Client {

    /// Receive a sync response, compute extra information out of it and store

    /// the interesting bits in the database, then call all the handlers.

    pub(crate) async fn process_sync(

        &self,

        response: sync_events::v3::Response,

    ) -> Result<BaseSyncResponse> {

        subscribe_to_room_latest_events(

            self,

            response.rooms.join.keys().chain(response.rooms.leave.keys()),

        )

        .await;

        let response = Box::pin(self.base_client().receive_sync_response(response)).await?;

        // Some new keys might have been received, so trigger a backup if needed.

        #[cfg(feature = "e2e-encryption")]

        self.encryption().backups().maybe_trigger_backup();

        self.call_sync_response_handlers(&response).await?;

        Ok(response)

    }

    /// Calls event handlers and notification handlers after a sync response has

    /// been processed.

    ///

    /// At this point, the sync response's data has been taken into account and

    /// persisted in the store, if needs be. This function is only calling

    /// the event, room update and notification handlers.

    #[tracing::instrument(skip(self, response))]

    pub(crate) async fn call_sync_response_handlers(

        &self,

        response: &BaseSyncResponse,

    ) -> Result<()> {

        let _timer = timer!(tracing::Level::TRACE, "_method");

        let BaseSyncResponse { rooms, presence, account_data, to_device, notifications } = response;

        let now = Instant::now();

        self.handle_sync_events(HandlerKind::GlobalAccountData, None, account_data).await?;

        self.handle_sync_events(HandlerKind::Presence, None, presence).await?;

        self.handle_sync_to_device_events(to_device).await?;

        self.send_room_updates(rooms.clone());

        for (room_id, room_info) in &rooms.joined {

            let Some(room) = self.get_room(room_id) else {

                error!(?room_id, "Can't call event handler, room not found");

                continue;

            };

            self.send_room_update(room_id, || RoomUpdate::Joined {

                room: room.clone(),

                updates: room_info.clone(),

            });

            let JoinedRoomUpdate {

                unread_notifications: _,

                timeline,

                state,

                account_data,

                ephemeral,

                ambiguity_changes: _,

                avatar_changes: _,

            } = room_info;

            let room = Some(&room);

            self.handle_sync_events(HandlerKind::RoomAccountData, room, account_data).await?;

            self.handle_sync_state_events(room, state).await?;

            self.handle_sync_timeline_events(room, &timeline.events).await?;

            // Handle ephemeral events after timeline, read receipts in here

            // could refer to timeline events from the same response.

            self.handle_sync_events(HandlerKind::EphemeralRoomData, room, ephemeral).await?;

        }

        for (room_id, room_info) in &rooms.left {

            let Some(room) = self.get_room(room_id) else {

                error!(?room_id, "Can't call event handler, room not found");

                continue;

            };

            self.send_room_update(room_id, || RoomUpdate::Left {

                room: room.clone(),

                updates: room_info.clone(),

            });

            let LeftRoomUpdate { timeline, state, account_data, ambiguity_changes: _ } = room_info;

            let room = Some(&room);

            self.handle_sync_events(HandlerKind::RoomAccountData, room, account_data).await?;

            self.handle_sync_state_events(room, state).await?;

            self.handle_sync_timeline_events(room, &timeline.events).await?;

        }

        for (room_id, room_info) in &rooms.invited {

            let Some(room) = self.get_room(room_id) else {

                error!(?room_id, "Can't call event handler, room not found");

                continue;

            };

            self.send_room_update(room_id, || RoomUpdate::Invited {

                room: room.clone(),

                updates: room_info.clone(),

            });

            let invite_state = &room_info.invite_state.events;

            self.handle_sync_events(HandlerKind::StrippedState, Some(&room), invite_state).await?;

        }

        for (room_id, room_info) in &rooms.knocked {

            let Some(room) = self.get_room(room_id) else {

                error!(?room_id, "Can't call event handler, room not found");

                continue;

            };

            self.send_room_update(room_id, || RoomUpdate::Knocked {

                room: room.clone(),

                updates: room_info.clone(),

            });

            let knock_state = &room_info.knock_state.events;

            self.handle_sync_events(HandlerKind::StrippedState, Some(&room), knock_state).await?;

        }

        debug!("Ran event handlers in {:?}", now.elapsed());

        let now = Instant::now();

        // Construct notification event handler futures

        let mut futures = Vec::new();

        for handler in &*self.notification_handlers().await {

            for (room_id, room_notifications) in notifications {

                let Some(room) = self.get_room(room_id) else {

                    warn!(?room_id, "Can't call notification handler, room not found");

                    continue;

                };

                futures.extend(room_notifications.iter().map(|notification| {

                    (handler)(notification.clone(), room.clone(), self.clone())

                }));

            }

        }

        // Run the notification handler futures with the

        // `self.notification_handlers` lock no longer being held, in order.

        for fut in futures {

            fut.await;

        }

        debug!("Ran notification handlers in {:?}", now.elapsed());

        Ok(())

    }

    fn send_room_update(&self, room_id: &RoomId, make_msg: impl FnOnce() -> RoomUpdate) {

        if let btree_map::Entry::Occupied(entry) =

            self.inner.room_update_channels.lock().unwrap().entry(room_id.to_owned())

        {

            let tx = entry.get();

            if tx.receiver_count() == 0 {

                entry.remove();

            } else {

                _ = tx.send(make_msg());

            }

        }

    }

    async fn sleep() {

        sleep(Duration::from_secs(1)).await;

    }

    pub(crate) async fn sync_loop_helper(

        &self,

        sync_settings: &mut crate::config::SyncSettings,

    ) -> Result<SyncResponse> {

        let response = self.sync_once(sync_settings.clone()).await;

        match response {

            Ok(r) => {

                sync_settings.token = r.next_batch.clone().into();

                Ok(r)

            }

            Err(e) => {

                error!("Received an invalid response: {e}");

                Err(e)

            }

        }

    }

    pub(crate) async fn delay_sync(last_sync_time: &mut Option<Instant>) {

        let now = Instant::now();

        // If the last sync happened less than a second ago, sleep for a

        // while to not hammer out requests if the server doesn't respect

        // the sync timeout.

        if let Some(t) = last_sync_time

            && now - *t <= Duration::from_secs(1)

        {

            Self::sleep().await;

        }

        *last_sync_time = Some(now);

    }

}

/// Call `LatestEvents::listen_to_room` for rooms in `response`.

///

/// That way, the latest event is computed and updated for all rooms receiving

/// an update from the sync.

#[instrument(skip_all)]

pub(crate) async fn subscribe_to_room_latest_events<'a, R>(client: &'a Client, room_ids: R)

where

    R: Iterator<Item = &'a OwnedRoomId>,

{

    if !client.event_cache().has_subscribed() {

        return;

    }

    let latest_events = client.latest_events().await;

    for room_id in room_ids {

        if let Err(error) = latest_events.listen_to_room(room_id).await {

            error!(?error, ?room_id, "Failed to listen to the latest event for this room");

        }

    }

}