fix(sync/v3): Cleanup part 1: mostly fix redundant data in state

src/service/account_data/mod.rs

@@ -129,13 +129,15 @@ pub fn changes_since<'a>(
 	&'a self,
 	room_id: Option<&'a RoomId>,
 	user_id: &'a UserId,
-	since: u64,
+	since: Option<u64>,
 	to: Option<u64>,
 ) -> impl Stream<Item = AnyRawAccountDataEvent> + Send + 'a {
 	type Key<'a> = (Option<&'a RoomId>, &'a UserId, u64, Ignore);
 
 	// Skip the data that's exactly at since, because we sent that last time
-	let first_possible = (room_id, user_id, since.saturating_add(1));
+	// ...unless this is an initial sync, in which case send everything
+	let first_possible =
+		(room_id, user_id, since.map(|since| since.saturating_add(1)).unwrap_or(0));
 
 	self.db
 		.roomuserdataid_accountdata

src/service/rooms/read_receipt/mod.rs

@@ -104,16 +104,16 @@ impl Service {
 		Ok(Raw::from_json(event))
 	}
 
-	/// Returns an iterator over the most recent read_receipts in a room that
-	/// happened after the event with id `since`.
+	/// Returns an iterator over the most recent read_receipts in a room,
+	/// optionally after the event with id `since`.
 	#[inline]
 	#[tracing::instrument(skip(self), level = "debug")]
 	pub fn readreceipts_since<'a>(
 		&'a self,
 		room_id: &'a RoomId,
-		since: u64,
+		since: Option<u64>,
 	) -> impl Stream<Item = ReceiptItem<'a>> + Send + 'a {
-		self.db.readreceipts_since(room_id, since)
+		self.db.readreceipts_since(room_id, since.unwrap_or(0))
 	}
 
 	/// Sets a private read marker at PDU `count`.

src/service/rooms/state_accessor/state.rs

@@ -1,7 +1,7 @@
 use std::{borrow::Borrow, ops::Deref, sync::Arc};
 
 use conduwuit::{
-	Result, at, err, implement,
+	Pdu, Result, at, err, implement,
 	matrix::{Event, StateKey},
 	pair_of,
 	utils::{
@@ -125,7 +125,7 @@ pub async fn state_get(
 	shortstatehash: ShortStateHash,
 	event_type: &StateEventType,
 	state_key: &str,
-) -> Result<impl Event> {
+) -> Result<Pdu> {
 	self.state_get_id(shortstatehash, event_type, state_key)
 		.and_then(async |event_id: OwnedEventId| self.services.timeline.get_pdu(&event_id).await)
 		.await

src/service/sending/sender.rs

@@ -423,7 +423,7 @@ impl Service {
 			let keys_changed = self
 				.services
 				.users
-				.room_keys_changed(room_id, since.0, None)
+				.room_keys_changed(room_id, Some(since.0), None)
 				.ready_filter(|(user_id, _)| self.services.globals.user_is_local(user_id));
 
 			pin_mut!(keys_changed);
@@ -520,7 +520,7 @@ impl Service {
 		let receipts = self
 			.services
 			.read_receipt
-			.readreceipts_since(room_id, since.0);
+			.readreceipts_since(room_id, Some(since.0));
 
 		pin_mut!(receipts);
 		let mut read = BTreeMap::<OwnedUserId, ReceiptData>::new();

src/service/users/mod.rs

@@ -790,7 +790,7 @@ impl Service {
 	pub fn keys_changed<'a>(
 		&'a self,
 		user_id: &'a UserId,
-		from: u64,
+		from: Option<u64>,
 		to: Option<u64>,
 	) -> impl Stream<Item = &'a UserId> + Send + 'a {
 		self.keys_changed_user_or_room(user_id.as_str(), from, to)
@@ -801,7 +801,7 @@ impl Service {
 	pub fn room_keys_changed<'a>(
 		&'a self,
 		room_id: &'a RoomId,
-		from: u64,
+		from: Option<u64>,
 		to: Option<u64>,
 	) -> impl Stream<Item = (&'a UserId, u64)> + Send + 'a {
 		self.keys_changed_user_or_room(room_id.as_str(), from, to)
@@ -810,11 +810,12 @@ impl Service {
 	fn keys_changed_user_or_room<'a>(
 		&'a self,
 		user_or_room_id: &'a str,
-		from: u64,
+		from: Option<u64>,
 		to: Option<u64>,
 	) -> impl Stream<Item = (&'a UserId, u64)> + Send + 'a {
 		type KeyVal<'a> = ((&'a str, u64), &'a UserId);
 
+		let from = from.unwrap_or(0);
 		let to = to.unwrap_or(u64::MAX);
 		let start = (user_or_room_id, from.saturating_add(1));
 		self.db