feat(devices): update the device last seen timestamp on usage

src/api/client_server/device.rs

@@ -17,8 +17,8 @@ pub async fn get_devices_route(
 
     let devices: Vec<device::Device> = services()
         .users
-        .all_devices_metadata(sender_user)
-        .filter_map(|r| r.ok()) // Filter out buggy devices
+        .all_user_devices_metadata(sender_user)
+        .await
         .collect();
 
     Ok(get_devices::v3::Response { devices })

src/api/ruma_wrapper/axum.rs

@@ -87,7 +87,12 @@ where
             if let Some(reg_info) = services().appservice.find_from_token(token).await {
                 Token::Appservice(Box::new(reg_info.clone()))
             } else if let Some((user_id, device_id)) = services().users.find_from_token(token)? {
-                Token::User((user_id, OwnedDeviceId::from(device_id)))
+                services()
+                    .users
+                    .update_device_last_seen(device_id.clone())
+                    .await;
+
+                Token::User((user_id, device_id))
             } else {
                 Token::Invalid
             }

src/api/server_server.rs

@@ -1778,8 +1778,8 @@ pub async fn get_devices_route(
             .expect("version will not grow that large"),
         devices: services()
             .users
-            .all_devices_metadata(&body.user_id)
-            .filter_map(|r| r.ok())
+            .all_user_devices_metadata(&body.user_id)
+            .await
             .filter_map(|metadata| {
                 Some(UserDevice {
                     keys: services()

src/database/key_value/users.rs

@@ -41,7 +41,7 @@ impl service::users::Data for KeyValueDatabase {
     }
 
     /// Find out which user an access token belongs to.
-    fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, String)>> {
+    fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, OwnedDeviceId)>> {
         self.token_userdeviceid
             .get(token.as_bytes())?
             .map_or(Ok(None), |bytes| {
@@ -60,9 +60,11 @@ impl service::users::Data for KeyValueDatabase {
                     .map_err(|_| {
                         Error::bad_database("User ID in token_userdeviceid is invalid.")
                     })?,
-                    utils::string_from_bytes(device_bytes).map_err(|_| {
+                    utils::string_from_bytes(device_bytes)
+                        .map_err(|_| {
                             Error::bad_database("Device ID in token_userdeviceid is invalid.")
-                    })?,
+                        })?
+                        .into(),
                 )))
             })
     }
@@ -896,7 +898,7 @@ impl service::users::Data for KeyValueDatabase {
             })
     }
 
-    fn all_devices_metadata<'a>(
+    fn all_user_devices_metadata<'a>(
         &'a self,
         user_id: &UserId,
     ) -> Box<dyn Iterator<Item = Result<Device>> + 'a> {
@@ -914,6 +916,46 @@ impl service::users::Data for KeyValueDatabase {
         )
     }
 
+    fn all_devices_metadata<'a>(
+        &'a self,
+    ) -> Box<dyn Iterator<Item = Result<(OwnedUserId, Device)>> + 'a> {
+        Box::new(self.userdeviceid_metadata.iter().map(|(user, bytes)| {
+            let binding = user.split(|&b| b == 0xff).collect::<Vec<_>>();
+            let user = binding
+                .first()
+                .ok_or_else(|| Error::bad_database("User ID in token_userdeviceid is invalid."))?
+                .to_vec();
+
+            if let (Ok(Ok(u)), Ok(d)) = (
+                utils::string_from_bytes(&user).map(UserId::parse),
+                serde_json::from_slice::<Device>(&bytes),
+            ) {
+                Ok((u, d))
+            } else {
+                Err(Error::bad_database(
+                    "Device and/or User in userdeviceid_metadata is invalid.",
+                ))
+            }
+        }))
+    }
+
+    fn set_devices_last_seen<'a>(
+        &'a self,
+        devices: &'a BTreeMap<OwnedDeviceId, MilliSecondsSinceUnixEpoch>,
+    ) -> Box<dyn Iterator<Item = Result<()>> + 'a> {
+        Box::new(
+            self.all_devices_metadata()
+                .filter_map(Result::ok)
+                .filter_map(|(u, mut d)| {
+                    d.last_seen_ts = Some(*devices.get(&d.device_id)?);
+                    Some((u, d))
+                })
+                .map(|(user, device)| {
+                    self.update_device_metadata(&user, &device.device_id, &device)
+                }),
+        )
+    }
+
     /// Creates a new sync filter. Returns the filter id.
     fn create_filter(&self, user_id: &UserId, filter: &FilterDefinition) -> Result<String> {
         let filter_id = utils::random_string(4);

src/database/mod.rs

@@ -988,6 +988,7 @@ impl KeyValueDatabase {
         services().sending.start_handler();
 
         Self::start_cleanup_task().await;
+        Self::start_device_last_seen_update_task();
         if services().globals.allow_check_for_updates() {
             Self::start_check_for_updates_task();
         }
@@ -1006,6 +1007,24 @@ impl KeyValueDatabase {
         res
     }
 
+    #[tracing::instrument]
+    pub fn start_device_last_seen_update_task() {
+        tokio::spawn(async move {
+            let timer_interval = Duration::from_secs(60);
+            let mut i = interval(timer_interval);
+            loop {
+                i.tick().await;
+                let _ = Self::try_update_device_last_seen().await;
+            }
+        });
+    }
+
+    async fn try_update_device_last_seen() {
+        for error in services().users.write_cached_last_seen().await {
+            warn!("Error writing last seen timestamp of device to database: {error}");
+        }
+    }
+
     #[tracing::instrument]
     pub fn start_check_for_updates_task() {
         tokio::spawn(async move {

src/service/mod.rs

@@ -114,6 +114,7 @@ impl Services {
             users: users::Service {
                 db,
                 connections: StdMutex::new(BTreeMap::new()),
+                device_last_seen: Mutex::new(BTreeMap::new()),
             },
             account_data: account_data::Service { db },
             admin: admin::Service::build(),

src/service/users/data.rs

@@ -4,8 +4,8 @@ use ruma::{
     encryption::{CrossSigningKey, DeviceKeys, OneTimeKey},
     events::AnyToDeviceEvent,
     serde::Raw,
-    DeviceId, DeviceKeyAlgorithm, DeviceKeyId, OwnedDeviceId, OwnedDeviceKeyId, OwnedMxcUri,
-    OwnedUserId, UInt, UserId,
+    DeviceId, DeviceKeyAlgorithm, DeviceKeyId, MilliSecondsSinceUnixEpoch, OwnedDeviceId,
+    OwnedDeviceKeyId, OwnedMxcUri, OwnedUserId, UInt, UserId,
 };
 use std::collections::BTreeMap;
 
@@ -20,7 +20,7 @@ pub trait Data: Send + Sync {
     fn count(&self) -> Result<usize>;
 
     /// Find out which user an access token belongs to.
-    fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, String)>>;
+    fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, OwnedDeviceId)>>;
 
     /// Returns an iterator over all users on this homeserver.
     fn iter<'a>(&'a self) -> Box<dyn Iterator<Item = Result<OwnedUserId>> + 'a>;
@@ -202,11 +202,20 @@ pub trait Data: Send + Sync {
 
     fn get_devicelist_version(&self, user_id: &UserId) -> Result<Option<u64>>;
 
-    fn all_devices_metadata<'a>(
+    fn all_user_devices_metadata<'a>(
         &'a self,
         user_id: &UserId,
     ) -> Box<dyn Iterator<Item = Result<Device>> + 'a>;
 
+    fn all_devices_metadata<'a>(
+        &'a self,
+    ) -> Box<dyn Iterator<Item = Result<(OwnedUserId, Device)>> + 'a>;
+
+    fn set_devices_last_seen<'a>(
+        &'a self,
+        devices: &'a BTreeMap<OwnedDeviceId, MilliSecondsSinceUnixEpoch>,
+    ) -> Box<dyn Iterator<Item = Result<()>> + 'a>;
+
     /// Creates a new sync filter. Returns the filter id.
     fn create_filter(&self, user_id: &UserId, filter: &FilterDefinition) -> Result<String>;
 

src/service/users/mod.rs

@@ -2,7 +2,7 @@ mod data;
 use std::{
     collections::{BTreeMap, BTreeSet},
     mem,
-    sync::{Arc, Mutex},
+    sync::{Arc, Mutex as StdMutex},
 };
 
 pub use data::Data;
@@ -19,9 +19,10 @@ use ruma::{
     encryption::{CrossSigningKey, DeviceKeys, OneTimeKey},
     events::AnyToDeviceEvent,
     serde::Raw,
-    DeviceId, DeviceKeyAlgorithm, DeviceKeyId, OwnedDeviceId, OwnedDeviceKeyId, OwnedMxcUri,
-    OwnedRoomId, OwnedUserId, RoomAliasId, UInt, UserId,
+    DeviceId, DeviceKeyAlgorithm, DeviceKeyId, MilliSecondsSinceUnixEpoch, OwnedDeviceId,
+    OwnedDeviceKeyId, OwnedMxcUri, OwnedRoomId, OwnedUserId, RoomAliasId, UInt, UserId,
 };
+use tokio::sync::Mutex;
 
 use crate::{services, Error, Result};
 
@@ -36,7 +37,8 @@ pub struct Service {
     pub db: &'static dyn Data,
     #[allow(clippy::type_complexity)]
     pub connections:
-        Mutex<BTreeMap<(OwnedUserId, OwnedDeviceId, String), Arc<Mutex<SlidingSyncCache>>>>,
+        StdMutex<BTreeMap<(OwnedUserId, OwnedDeviceId, String), Arc<StdMutex<SlidingSyncCache>>>>,
+    pub device_last_seen: Mutex<BTreeMap<OwnedDeviceId, MilliSecondsSinceUnixEpoch>>,
 }
 
 impl Service {
@@ -72,7 +74,7 @@ impl Service {
             cache
                 .entry((user_id, device_id, conn_id))
                 .or_insert_with(|| {
-                    Arc::new(Mutex::new(SlidingSyncCache {
+                    Arc::new(StdMutex::new(SlidingSyncCache {
                         lists: BTreeMap::new(),
                         subscriptions: BTreeMap::new(),
                         known_rooms: BTreeMap::new(),
@@ -200,7 +202,7 @@ impl Service {
             cache
                 .entry((user_id, device_id, conn_id))
                 .or_insert_with(|| {
-                    Arc::new(Mutex::new(SlidingSyncCache {
+                    Arc::new(StdMutex::new(SlidingSyncCache {
                         lists: BTreeMap::new(),
                         subscriptions: BTreeMap::new(),
                         known_rooms: BTreeMap::new(),
@@ -228,7 +230,7 @@ impl Service {
             cache
                 .entry((user_id, device_id, conn_id))
                 .or_insert_with(|| {
-                    Arc::new(Mutex::new(SlidingSyncCache {
+                    Arc::new(StdMutex::new(SlidingSyncCache {
                         lists: BTreeMap::new(),
                         subscriptions: BTreeMap::new(),
                         known_rooms: BTreeMap::new(),
@@ -289,7 +291,7 @@ impl Service {
     }
 
     /// Find out which user an access token belongs to.
-    pub fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, String)>> {
+    pub fn find_from_token(&self, token: &str) -> Result<Option<(OwnedUserId, OwnedDeviceId)>> {
         self.db.find_from_token(token)
     }
 
@@ -563,11 +565,25 @@ impl Service {
         self.db.get_devicelist_version(user_id)
     }
 
-    pub fn all_devices_metadata<'a>(
+    pub async fn all_user_devices_metadata<'a>(
         &'a self,
         user_id: &UserId,
-    ) -> impl Iterator<Item = Result<Device>> + 'a {
-        self.db.all_devices_metadata(user_id)
+    ) -> impl Iterator<Item = Device> + 'a {
+        let all_devices: Vec<_> = self
+            .db
+            .all_user_devices_metadata(user_id)
+            .filter_map(Result::ok)
+            // RumaHandler trait complains if we don't collect
+            .collect();
+        let device_last_seen = self.device_last_seen.lock().await;
+
+        // Updates the timestamps with the cached ones
+        all_devices.into_iter().map(move |mut d| {
+            if let Some(ts) = device_last_seen.get(&d.device_id) {
+                d.last_seen_ts = Some(*ts);
+            };
+            d
+        })
     }
 
     /// Deactivate account
@@ -608,6 +624,31 @@ impl Service {
     pub fn find_from_openid_token(&self, token: &str) -> Result<Option<OwnedUserId>> {
         self.db.find_from_openid_token(token)
     }
+
+    /// Sets the device_last_seen timestamp of a given device to now
+    pub async fn update_device_last_seen(&self, device_id: OwnedDeviceId) {
+        self.device_last_seen
+            .lock()
+            .await
+            .insert(device_id, MilliSecondsSinceUnixEpoch::now());
+    }
+
+    /// Writes all the currently cached last seen timestamps of devices to the database,
+    /// clearing the cache in the process
+    pub async fn write_cached_last_seen(&self) -> Vec<Error> {
+        let mut map = self.device_last_seen.lock().await;
+        if !map.is_empty() {
+            let result = self
+                .db
+                .set_devices_last_seen(&map)
+                .filter_map(Result::err)
+                .collect();
+            map.clear();
+            result
+        } else {
+            Vec::new()
+        }
+    }
 }
 
 /// Ensure that a user only sees signatures from themselves and the target user