Also adds some traces

@@ -90,0 +103,4 @@
+	State(services): State<crate::State>,
+	body: Ruma<get_remote_server_keys_batch::v2::Request>,
+) -> Result<get_remote_server_keys_batch::v2::Response> {
+	let total_queried_keys = body

@@ -90,0 +119,4 @@
+	let mut response = Vec::with_capacity(total_queried_keys);
+
+	for (server_name, queries) in &body.server_keys {
+		if queries.is_empty() {

@@ -90,0 +151,4 @@
+			else {
+				continue;
+			};
+			if ssk.valid_until_ts < minimum_valid_until_ts || ssk.valid_until_ts > in_one_week() {

@@ -90,0 +137,4 @@
+		// )));
+	}
+	if total_queried_keys > MAX_KEYS_PER_QUERY {
+		// We shouldn't really enforce this before MSC4456 either, but not doing

@@ -90,0 +203,4 @@
+	// First contact the origin (if we're allowed to)
+	if server_keys.notary_may_contact_origin(&remote) {
+		debug_info!("Asking remote directly for verify keys");
+		if let Ok(res) = server_keys.origin_request(remote.clone(), start).await

@@ -90,0 +209,4 @@
+			let index = results.len();
+			results.push(ssk);
+			for key_id in res.verify_keys.keys().chain(res.old_verify_keys.keys()) {
+				if queries.is_empty()

@@ -90,0 +213,4 @@
+					|| queries
+						.get(key_id)
+						.and_then(|c| c.minimum_valid_until_ts)
+						.is_none_or(|m| res.valid_until_ts >= m)

@@ -90,0 +322,4 @@
+		.notary_may_contact_origin(&body.server_name)
+		&& let Ok(response) = services
+			.server_keys
+			.origin_request(body.server_name.clone(), min_valid_ts)

@@ -90,0 +242,4 @@
+				}
+			})
+			.ready_for_each(|signed_ssk| {
+				let ssk = signed_ssk.deserialize().unwrap();

@@ -90,0 +332,4 @@
+			services.globals.server_name(),
+		)
+		.await
+		.map(|r| Ok(get_remote_server_keys::v2::Response::new(vec![r])))?;

@@ -90,0 +271,4 @@
+			continue;
+		};
+
+		if ssk.valid_until_ts < minimum_valid_until_ts || ssk.valid_until_ts > in_one_week() {

@@ -29,6 +34,7 @@ pub struct Service {
 	verify_keys: VerifyKeys,
 	services: Services,
 	db: Data,
+	last_lookup: SyncRwLock<HashMap<OwnedServerName, Instant>>,

@@ -101,3 +101,3 @@
 		};
 		let mut canonical_object = to_canonical_object(notary_signatures)?;
-		Self::strip_extraneous_signatures(&mut canonical_object, &server_keys.server_name, &[
+		strip_extraneous_signatures(&mut canonical_object, &server_keys.server_name, &[

@@ -90,0 +119,4 @@
+	}
+
+	let total_queried_servers = body.server_keys.len();
+	let total_queried_keys = body

@@ -28,0 +59,4 @@
+	State(services): State<crate::State>,
+	body: Ruma<get_remote_server_keys_batch::v2::Request>,
+) -> Result<get_remote_server_keys_batch::v2::Response> {
+	query_inner(&services, &body.server_keys, false)

@@ -28,0 +99,7 @@
+	// Count how many keys are being requested.
+	// Each server incurs a cost of at least one, and then the count of each key
+	// being queried per-server.
+	let total_queried_servers = body.len();
+	let total_queried_keys = body
+		.values()
+		.fold(body.len(), |acc, q| acc.saturating_add(q.len()));

@@ -28,0 +122,4 @@
+		total_queried_servers > MAX_SERVERS_PER_QUERY || total_queried_keys > MAX_KEYS_PER_QUERY;
+
+	debug_info!("Fetching {total_queried_keys} keys across {} servers", body.len());
+	let mut futs: FuturesUnordered<_> = FuturesUnordered::new();

@@ -83,0 +273,4 @@
+		let minimum_valid_until_ts = criteria
+			.clone()
+			.minimum_valid_until_ts
+			.unwrap_or_else(|| MilliSecondsSinceUnixEpoch(uint!(0)));

@@ -0,0 +23,4 @@
+		rate_limited: true,
+		authentication: ServerSignatures,
+		history: {
+			unstable("org.continuwuity.msc4553") => "/_matrix/key/unstable/org.continuwuity.msc4556/query",

@@ -196,0 +260,4 @@
+			// We need to verify that this response is still trusted based on
+			// the current configuration. It's possible we got this response
+			// from a notary who we no longer trust.
+			if resp.valid_until_ts > in_one_week() || resp.valid_until_ts < now {

@@ -100,13 +100,12 @@ impl super::Service {
 			)));
 		};
 		let mut canonical_object = to_canonical_object(notary_signatures)?;