Use #[expect], lint reasons

src/database/abstraction/rocksdb.rs

@@ -72,10 +72,11 @@ fn db_options(max_open_files: i32, rocksdb_cache: &Cache) -> Options {
 
 impl KeyValueDatabaseEngine for Arc<Engine> {
     fn open(config: &Config) -> Result<Self> {
-        #[allow(
+        #[expect(
             clippy::as_conversions,
             clippy::cast_sign_loss,
-            clippy::cast_possible_truncation
+            clippy::cast_possible_truncation,
+            reason = "saturating to usize is fine"
         )]
         let cache_capacity_bytes =
             (config.database.cache_capacity_mb * 1024.0 * 1024.0) as usize;
@@ -144,7 +145,11 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
         }))
     }
 
-    #[allow(clippy::as_conversions, clippy::cast_precision_loss)]
+    #[expect(
+        clippy::as_conversions,
+        clippy::cast_precision_loss,
+        reason = "these are just informational"
+    )]
     fn memory_usage(&self) -> Result<String> {
         let stats =
             get_memory_usage_stats(Some(&[&self.rocks]), Some(&[&self.cache]))?;

src/database/abstraction/sqlite.rs

@@ -124,11 +124,12 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
         // 2. divide by permanent connections + permanent iter connections +
         //    write connection
         // 3. round down to nearest integer
-        #[allow(
+        #[expect(
             clippy::as_conversions,
             clippy::cast_possible_truncation,
             clippy::cast_precision_loss,
-            clippy::cast_sign_loss
+            clippy::cast_sign_loss,
+            reason = "saturating to u32 is fine"
         )]
         let cache_size_per_thread =
             ((config.database.cache_capacity_mb * 1024.0)

src/database/abstraction/watchers.rs

@@ -9,7 +9,10 @@ use tokio::sync::watch;
 
 #[derive(Default)]
 pub(super) struct Watchers {
-    #[allow(clippy::type_complexity)]
+    #[expect(
+        clippy::type_complexity,
+        reason = "not actually all that complex"
+    )]
     watchers:
         RwLock<HashMap<Vec<u8>, (watch::Sender<()>, watch::Receiver<()>)>>,
 }

src/database/key_value/rooms/edus/read_receipt.rs

@@ -53,7 +53,7 @@ impl service::rooms::edus::read_receipt::Data for KeyValueDatabase {
     }
 
     #[tracing::instrument(skip(self))]
-    #[allow(clippy::type_complexity)]
+    #[expect(clippy::type_complexity)]
     fn readreceipts_since<'a>(
         &'a self,
         room_id: &RoomId,

src/database/key_value/rooms/search.rs

@@ -64,7 +64,7 @@ impl service::rooms::search::Data for KeyValueDatabase {
     }
 
     #[tracing::instrument(skip(self))]
-    #[allow(clippy::type_complexity)]
+    #[expect(clippy::type_complexity)]
     fn search_pdus<'a>(
         &'a self,
         room_id: &RoomId,

src/database/key_value/rooms/state_cache.rs

@@ -482,7 +482,7 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
     }
 
     /// Returns an iterator over all rooms a user was invited to.
-    #[allow(clippy::type_complexity)]
+    #[expect(clippy::type_complexity)]
     #[tracing::instrument(skip(self))]
     fn rooms_invited<'a>(
         &'a self,
@@ -575,7 +575,7 @@ impl service::rooms::state_cache::Data for KeyValueDatabase {
     }
 
     /// Returns an iterator over all rooms a user left.
-    #[allow(clippy::type_complexity)]
+    #[expect(clippy::type_complexity)]
     #[tracing::instrument(skip(self))]
     fn rooms_left<'a>(
         &'a self,