add BoundedVec generic struct

crates/ptth_relay/src/relay_state.rs

@@ -70,13 +70,6 @@ impl Default for ServerStatus {
 	}
 }
 
-#[derive (Clone)]
-pub struct RejectedServer {
-	pub name: String,
-	pub tripcode: blake3::Hash,
-	pub seen: DateTime <Utc>,
-}
-
 pub struct RelayState {
 	pub config: RwLock <Config>,
 	
@@ -94,6 +87,34 @@ pub struct RelayState {
 	pub unregistered_servers: RwLock <Vec <RejectedServer>>,
 }
 
+pub struct BoundedVec <T: Clone> {
+	bound: usize,
+	v: RwLock <Vec <T>>,
+}
+
+impl <T: Clone> BoundedVec <T> {
+	pub async fn to_vec (&self) -> Vec <T> {
+		let guard = self.v.read ().await;
+		(*guard).clone ()
+	}
+	
+	pub async fn push (&mut self, x: T) {
+		let mut guard = self.v.write ().await;
+		guard.push (x);
+		
+		while guard.len () > self.bound {
+			guard.remove (0);
+		}
+	}
+}
+
+#[derive (Clone)]
+pub struct RejectedServer {
+	pub name: String,
+	pub tripcode: blake3::Hash,
+	pub seen: DateTime <Utc>,
+}
+
 impl TryFrom <Config> for RelayState {
 	type Error = RelayError;