resolve almost all as_conversions lints

may need further opinion from others on these

Signed-off-by: strawberry <strawberry@puppygock.gay>

Cargo.toml

@@ -626,6 +626,7 @@ trivially_copy_pass_by_ref = "warn"
 wildcard_imports = "warn"
 checked_conversions = "warn"
 #integer_arithmetic = "warn"
+#as_conversions = "warn"
 
 # some sadness
 missing_errors_doc = "allow"
@@ -646,7 +647,6 @@ map_err_ignore = "allow"
 missing_docs_in_private_items = "allow"
 multiple_inherent_impl = "allow"
 error_impl_error = "allow"
-as_conversions = "allow"
 string_add = "allow"
 string_slice = "allow"
 ref_patterns = "allow"

src/api/client_server/backup.rs

@@ -1,4 +1,5 @@
-use ruma::api::client::{
+use ruma::{
+	api::client::{
 		backup::{
 			add_backup_keys, add_backup_keys_for_room, add_backup_keys_for_session, create_backup_version,
 			delete_backup_keys, delete_backup_keys_for_room, delete_backup_keys_for_session, delete_backup_version,
@@ -6,6 +7,8 @@ use ruma::api::client::{
 			get_latest_backup_info, update_backup_version,
 		},
 		error::ErrorKind,
+	},
+	UInt,
 };
 
 use crate::{services, Error, Result, Ruma};
@@ -56,7 +59,8 @@ pub(crate) async fn get_latest_backup_info_route(
 
 	Ok(get_latest_backup_info::v3::Response {
 		algorithm,
-		count: (services().key_backups.count_keys(sender_user, &version)? as u32).into(),
+		count: (UInt::try_from(services().key_backups.count_keys(sender_user, &version)?)
+			.expect("user backup keys count should not be that high")),
 		etag: services().key_backups.get_etag(sender_user, &version)?,
 		version,
 	})
@@ -76,10 +80,12 @@ pub(crate) async fn get_backup_info_route(
 
 	Ok(get_backup_info::v3::Response {
 		algorithm,
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -139,10 +145,12 @@ pub(crate) async fn add_backup_keys_route(
 	}
 
 	Ok(add_backup_keys::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -181,10 +189,12 @@ pub(crate) async fn add_backup_keys_for_room_route(
 	}
 
 	Ok(add_backup_keys_for_room::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -221,10 +231,12 @@ pub(crate) async fn add_backup_keys_for_session_route(
 		.add_key(sender_user, &body.version, &body.room_id, &body.session_id, &body.session_data)?;
 
 	Ok(add_backup_keys_for_session::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -294,10 +306,12 @@ pub(crate) async fn delete_backup_keys_route(
 		.delete_all_keys(sender_user, &body.version)?;
 
 	Ok(delete_backup_keys::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -317,10 +331,12 @@ pub(crate) async fn delete_backup_keys_for_room_route(
 		.delete_room_keys(sender_user, &body.version, &body.room_id)?;
 
 	Ok(delete_backup_keys_for_room::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,
@@ -340,10 +356,12 @@ pub(crate) async fn delete_backup_keys_for_session_route(
 		.delete_room_key(sender_user, &body.version, &body.room_id, &body.session_id)?;
 
 	Ok(delete_backup_keys_for_session::v3::Response {
-		count: (services()
+		count: (UInt::try_from(
+			services()
 				.key_backups
-			.count_keys(sender_user, &body.version)? as u32)
+				.count_keys(sender_user, &body.version)?,
-			.into(),
+		)
+		.expect("user backup keys count should not be that high")),
 		etag: services()
 			.key_backups
 			.get_etag(sender_user, &body.version)?,

src/api/client_server/context.rs

@@ -63,8 +63,8 @@ pub(crate) async fn get_context_route(body: Ruma<get_context::v3::Request>) -> R
 		lazy_loaded.insert(base_event.sender.as_str().to_owned());
 	}
 
-	// Use limit with maximum 100
+	// Use limit or else 10, with maximum 100
-	let limit = u64::from(body.limit).min(100) as usize;
+	let limit = usize::try_from(body.limit).unwrap_or(10).min(100);
 
 	let base_event = base_event.to_room_event();
 

src/api/client_server/directory.rs

@@ -20,7 +20,7 @@ use ruma::{
 		},
 		StateEventType,
 	},
-	ServerName, UInt,
+	uint, ServerName, UInt,
 };
 use tracing::{error, info, warn};
 
@@ -198,8 +198,9 @@ pub(crate) async fn get_public_rooms_filtered_helper(
 		});
 	}
 
+	// Use limit or else 10, with maximum 100
 	let limit = limit.map_or(10, u64::from);
-	let mut num_since = 0_u64;
+	let mut num_since: u64 = 0;
 
 	if let Some(s) = &since {
 		let mut characters = s.chars();
@@ -363,12 +364,16 @@ pub(crate) async fn get_public_rooms_filtered_helper(
 
 	all_rooms.sort_by(|l, r| r.num_joined_members.cmp(&l.num_joined_members));
 
-	let total_room_count_estimate = (all_rooms.len() as u32).into();
+	let total_room_count_estimate = UInt::try_from(all_rooms.len()).unwrap_or_else(|_| uint!(0));
 
 	let chunk: Vec<_> = all_rooms
 		.into_iter()
-		.skip(num_since as usize)
+		.skip(
-		.take(limit as usize)
+			num_since
+				.try_into()
+				.expect("num_since should not be this high"),
+		)
+		.take(limit.try_into().expect("limit should not be this high"))
 		.collect();
 
 	let prev_batch = if num_since == 0 {
@@ -377,7 +382,7 @@ pub(crate) async fn get_public_rooms_filtered_helper(
 		Some(format!("p{num_since}"))
 	};
 
-	let next_batch = if chunk.len() < limit as usize {
+	let next_batch = if chunk.len() < limit.try_into().unwrap() {
 		None
 	} else {
 		Some(format!(

src/api/client_server/message.rs

@@ -144,7 +144,7 @@ pub(crate) async fn get_message_events_route(
 		.lazy_load_confirm_delivery(sender_user, sender_device, &body.room_id, from)
 		.await?;
 
-	let limit = u64::from(body.limit).min(100) as usize;
+	let limit = usize::try_from(body.limit).unwrap_or(10).min(100);
 
 	let next_token;
 
@@ -159,8 +159,9 @@ pub(crate) async fn get_message_events_route(
 				.timeline
 				.pdus_after(sender_user, &body.room_id, from)?
 				.filter_map(Result::ok) // Filter out buggy events
-				.filter(|(_, pdu)| contains_url_filter(pdu, &body.filter))
+				.filter(|(_, pdu)| { contains_url_filter(pdu, &body.filter) && visibility_filter(pdu, sender_user, &body.room_id)
-				.filter(|(_, pdu)| visibility_filter(pdu, sender_user, &body.room_id))
+
+				})
 				.take_while(|&(k, _)| Some(k) != to) // Stop at `to`
 				.take(limit)
 				.collect();
@@ -205,8 +206,7 @@ pub(crate) async fn get_message_events_route(
 				.timeline
 				.pdus_until(sender_user, &body.room_id, from)?
 				.filter_map(Result::ok) // Filter out buggy events
-				.filter(|(_, pdu)| contains_url_filter(pdu, &body.filter))
+				.filter(|(_, pdu)| {contains_url_filter(pdu, &body.filter) && visibility_filter(pdu, sender_user, &body.room_id)})
-				.filter(|(_, pdu)| visibility_filter(pdu, sender_user, &body.room_id))
 				.take_while(|&(k, _)| Some(k) != to) // Stop at `to`
 				.take(limit)
 				.collect();

src/api/client_server/search.rs

@@ -10,7 +10,7 @@ use ruma::{
 	},
 	events::AnyStateEvent,
 	serde::Raw,
-	OwnedRoomId,
+	uint, OwnedRoomId,
 };
 use tracing::debug;
 
@@ -39,7 +39,12 @@ pub(crate) async fn search_events_route(body: Ruma<search_events::v3::Request>)
 	});
 
 	// Use limit or else 10, with maximum 100
-	let limit = filter.limit.map_or(10, u64::from).min(100) as usize;
+	let limit: usize = filter
+		.limit
+		.unwrap_or_else(|| uint!(10))
+		.try_into()
+		.unwrap_or(10)
+		.min(100);
 
 	let mut room_states: BTreeMap<OwnedRoomId, Vec<Raw<AnyStateEvent>>> = BTreeMap::new();
 
@@ -167,7 +172,7 @@ pub(crate) async fn search_events_route(body: Ruma<search_events::v3::Request>)
 
 	Ok(search_events::v3::Response::new(ResultCategories {
 		room_events: ResultRoomEvents {
-			count: Some((results.len() as u32).into()),
+			count: Some(results.len().try_into().unwrap_or_else(|_| uint!(0))),
 			groups: BTreeMap::new(), // TODO
 			next_batch,
 			results,

src/api/client_server/space.rs

@@ -2,7 +2,7 @@ use std::str::FromStr;
 
 use ruma::{
 	api::client::{error::ErrorKind, space::get_hierarchy},
-	UInt,
+	uint, UInt,
 };
 
 use crate::{service::rooms::spaces::PagnationToken, services, Error, Result, Ruma};
@@ -14,10 +14,12 @@ use crate::{service::rooms::spaces::PagnationToken, services, Error, Result, Rum
 pub(crate) async fn get_hierarchy_route(body: Ruma<get_hierarchy::v1::Request>) -> Result<get_hierarchy::v1::Response> {
 	let sender_user = body.sender_user.as_ref().expect("user is authenticated");
 
-	let limit = body
+	let limit: usize = body
 		.limit
-		.unwrap_or_else(|| UInt::from(10_u32))
+		.unwrap_or_else(|| uint!(10))
-		.min(UInt::from(100_u32));
+		.try_into()
+		.unwrap_or(10)
+		.min(100);
 
 	let max_depth = body
 		.max_depth
@@ -45,9 +47,9 @@ pub(crate) async fn get_hierarchy_route(body: Ruma<get_hierarchy::v1::Request>)
 		.get_client_hierarchy(
 			sender_user,
 			&body.room_id,
-			u64::from(limit) as usize,
+			limit,
-			key.map_or(0, |token| u64::from(token.skip) as usize),
+			key.map_or(0, |token| token.skip.try_into().unwrap_or(0)),
-			u64::from(max_depth) as usize,
+			max_depth.try_into().unwrap_or(3),
 			body.suggested_only,
 		)
 		.await

src/api/client_server/threads.rs

@@ -1,4 +1,7 @@
-use ruma::api::client::{error::ErrorKind, threads::get_threads};
+use ruma::{
+	api::client::{error::ErrorKind, threads::get_threads},
+	uint,
+};
 
 use crate::{services, Error, Result, Ruma};
 
@@ -9,7 +12,8 @@ pub(crate) async fn get_threads_route(body: Ruma<get_threads::v1::Request>) -> R
 	// Use limit or else 10, with maximum 100
 	let limit = body
 		.limit
-		.and_then(|l| l.try_into().ok())
+		.unwrap_or_else(|| uint!(10))
+		.try_into()
 		.unwrap_or(10)
 		.min(100);
 

src/api/client_server/user_directory.rs

@@ -17,7 +17,7 @@ use crate::{services, Result, Ruma};
 /// and don't share a room with the sender
 pub(crate) async fn search_users_route(body: Ruma<search_users::v3::Request>) -> Result<search_users::v3::Response> {
 	let sender_user = body.sender_user.as_ref().expect("user is authenticated");
-	let limit = u64::from(body.limit) as usize;
+	let limit = usize::try_from(body.limit).unwrap_or(10); // default limit is 10
 
 	let mut users = services().users.iter().filter_map(|user_id| {
 		// Filter out buggy users (they should not exist, but you never know...)

src/database/mod.rs

@@ -340,6 +340,7 @@ impl KeyValueDatabase {
 
 			roomid_inviteviaservers: builder.open_tree("roomid_inviteviaservers")?,
 
+			#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 			auth_chain_cache: Mutex::new(LruCache::new(
 				(f64::from(config.auth_chain_cache_capacity) * config.conduit_cache_capacity_modifier) as usize,
 			)),

src/database/rocksdb/mod.rs

@@ -35,7 +35,11 @@ pub(crate) struct Engine {
 impl KeyValueDatabaseEngine for Arc<Engine> {
 	fn open(config: &Config) -> Result<Self> {
 		let cache_capacity_bytes = config.db_cache_capacity_mb * 1024.0 * 1024.0;
+
+		#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 		let row_cache_capacity_bytes = (cache_capacity_bytes * 0.50) as usize;
+
+		#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 		let col_cache_capacity_bytes = (cache_capacity_bytes * 0.50) as usize;
 
 		let mut col_cache = HashMap::new();
@@ -128,6 +132,7 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 		Ok(())
 	}
 
+	#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 	fn memory_usage(&self) -> Result<String> {
 		let mut res = String::new();
 		let stats = rust_rocksdb::perf::get_memory_usage_stats(Some(&[&self.rocks]), Some(&[&self.row_cache]))?;

src/database/sqlite/mod.rs

@@ -21,7 +21,7 @@ thread_local! {
 
 struct PreparedStatementIterator<'a> {
 	iterator: Box<dyn Iterator<Item = TupleOfBytes> + 'a>,
-	_statement_ref: NonAliasingBox<rusqlite::Statement<'a>>,
+	_statement_ref: AliasableBox<rusqlite::Statement<'a>>,
 }
 
 impl Iterator for PreparedStatementIterator<'_> {
@@ -30,16 +30,25 @@ impl Iterator for PreparedStatementIterator<'_> {
 	fn next(&mut self) -> Option<Self::Item> { self.iterator.next() }
 }
 
-struct NonAliasingBox<T>(*mut T);
+struct AliasableBox<T>(*mut T);
-impl<T> Drop for NonAliasingBox<T> {
+impl<T> Drop for AliasableBox<T> {
 	fn drop(&mut self) {
-		// TODO: figure out why this is necessary, but also this is sqlite so dont think
+		// SAFETY: This is cursed and relies on non-local reasoning.
-		// i care that much. i tried checking commit history but couldn't find out why
+		//
-		// this was done.
+		// In order for this to be safe:
-		#[allow(clippy::undocumented_unsafe_blocks)]
+		//
-		unsafe {
+		// * All aliased references to this value must have been dropped first, for
-			_ = Box::from_raw(self.0);
+		//   example by coming after its referrers in struct fields, because struct
-		};
+		//   fields are automatically dropped in order from top to bottom in the absence
+		//   of an explicit Drop impl. Otherwise, the referrers may read into
+		//   deallocated memory.
+		// * This type must not be copyable or cloneable. Otherwise, double-free can
+		//   occur.
+		//
+		// These conditions are met, but again, note that changing safe code in
+		// this module can result in unsoundness if any of these constraints are
+		// violated.
+		unsafe { drop(Box::from_raw(self.0)) }
 	}
 }
 
@@ -93,8 +102,13 @@ impl KeyValueDatabaseEngine for Arc<Engine> {
 		// 2. divide by permanent connections + permanent iter connections + write
 		//    connection
 		// 3. round down to nearest integer
-		let cache_size_per_thread: u32 =
+		#[allow(
-			((config.db_cache_capacity_mb * 1024.0) / ((num_cpus::get().max(1) * 2) + 1) as f64) as u32;
+			clippy::as_conversions,
+			clippy::cast_possible_truncation,
+			clippy::cast_precision_loss,
+			clippy::cast_sign_loss
+		)]
+		let cache_size_per_thread = ((config.db_cache_capacity_mb * 1024.0) / ((num_cpus::get() as f64 * 2.0) + 1.0)) as u32;
 
 		let writer = Mutex::new(Engine::prepare_conn(&path, cache_size_per_thread)?);
 
@@ -161,7 +175,7 @@ impl SqliteTable {
 				.unwrap(),
 		));
 
-		let statement_ref = NonAliasingBox(statement);
+		let statement_ref = AliasableBox(statement);
 
 		//let name = self.name.clone();
 
@@ -250,7 +264,7 @@ impl KvTree for SqliteTable {
 					.unwrap(),
 			));
 
-			let statement_ref = NonAliasingBox(statement);
+			let statement_ref = AliasableBox(statement);
 
 			let iterator = Box::new(
 				statement
@@ -272,7 +286,7 @@ impl KvTree for SqliteTable {
 					.unwrap(),
 			));
 
-			let statement_ref = NonAliasingBox(statement);
+			let statement_ref = AliasableBox(statement);
 
 			let iterator = Box::new(
 				statement

src/database/watchers.rs

@@ -47,7 +47,7 @@ impl Watchers {
 			let mut watchers = self.watchers.write().unwrap();
 			for prefix in triggered {
 				if let Some(tx) = watchers.remove(prefix) {
-					_ = tx.0.send(());
+					tx.0.send(()).expect("channel should still be open");
 				}
 			}
 		};

src/service/globals/resolver.rs

@@ -30,6 +30,7 @@ pub(crate) struct Hooked {
 }
 
 impl Resolver {
+	#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 	pub(crate) fn new(config: &Config) -> Self {
 		let (sys_conf, mut opts) = hickory_resolver::system_conf::read_system_conf()
 			.map_err(|e| {

src/service/mod.rs

@@ -40,6 +40,7 @@ pub(crate) struct Services<'a> {
 }
 
 impl Services<'_> {
+	#[allow(clippy::as_conversions, clippy::cast_sign_loss, clippy::cast_possible_truncation)]
 	pub(crate) fn build<
 		D: appservice::Data
 			+ pusher::Data

src/service/pusher/mod.rs

@@ -188,13 +188,14 @@ impl Service {
 
 		let ctx = PushConditionRoomCtx {
 			room_id: room_id.to_owned(),
-			member_count: UInt::from(
+			member_count: UInt::try_from(
 				services()
 					.rooms
 					.state_cache
 					.room_joined_count(room_id)?
-					.unwrap_or(1) as u32,
+					.unwrap_or(1),
-			),
+			)
+			.unwrap_or_else(|_| uint!(0)),
 			user_id: user.to_owned(),
 			user_display_name: services()
 				.users

src/service/rooms/pdu_metadata/mod.rs

@@ -5,7 +5,7 @@ pub(crate) use data::Data;
 use ruma::{
 	api::{client::relations::get_relating_events, Direction},
 	events::{relation::RelationType, TimelineEventType},
-	EventId, RoomId, UInt, UserId,
+	uint, EventId, RoomId, UInt, UserId,
 };
 use serde::Deserialize;
 
@@ -57,8 +57,9 @@ impl Service {
 
 		// Use limit or else 10, with maximum 100
 		let limit = limit
-			.and_then(|u| u32::try_from(u).ok())
+			.unwrap_or_else(|| uint!(10))
-			.map_or(10_usize, |u| u as usize)
+			.try_into()
+			.unwrap_or(10)
 			.min(100);
 
 		let next_token;

src/utils/mod.rs

@@ -21,6 +21,7 @@ use crate::{services, Error, Result};
 
 pub(crate) fn clamp<T: Ord>(val: T, min: T, max: T) -> T { cmp::min(cmp::max(val, min), max) }
 
+#[allow(clippy::as_conversions)]
 pub(crate) fn millis_since_unix_epoch() -> u64 {
 	SystemTime::now()
 		.duration_since(UNIX_EPOCH)