despawn entities when switching worlds and some testbot fixes

azalea-client/src/client.rs

@@ -555,6 +555,11 @@ impl Client {
         self.query::<Option<&T>>(&mut self.ecs.lock()).cloned()
     }
 
+    /// Get a resource from the ECS. This will clone the resource and return it.
+    pub fn resource<T: Resource + Clone>(&self) -> T {
+        self.ecs.lock().resource::<T>().clone()
+    }
+
     /// Get a required component for this client and call the given function.
     ///
     /// Similar to [`Self::component`], but doesn't clone the component since

azalea-client/src/disconnect.rs

@@ -47,6 +47,7 @@ pub struct DisconnectEvent {
 pub fn remove_components_from_disconnected_players(
     mut commands: Commands,
     mut events: EventReader<DisconnectEvent>,
+    mut loaded_by_query: Query<&mut azalea_entity::LoadedBy>,
 ) {
     for DisconnectEvent { entity, .. } in events.read() {
         trace!("Got DisconnectEvent for {entity:?}");
@@ -62,6 +63,13 @@ pub fn remove_components_from_disconnected_players(
             .remove::<LocalPlayerEvents>();
         // note that we don't remove the client from the ECS, so if they decide
         // to reconnect they'll keep their state
+
+        // now we have to remove ourselves from the LoadedBy for every entity.
+        // in theory this could be inefficient if we have massive swarms... but in
+        // practice this is fine.
+        for mut loaded_by in &mut loaded_by_query.iter_mut() {
+            loaded_by.remove(entity);
+        }
     }
 }
 

azalea-entity/src/plugin/indexing.rs

@@ -155,8 +155,8 @@ pub fn remove_despawned_entities_from_indexes(
         Changed<LoadedBy>,
     >,
 ) {
-    for (entity, uuid, minecraft_id, position, world_name, loaded_by) in &query {
-        let Some(instance_lock) = instance_container.get(world_name) else {
+    for (entity, uuid, minecraft_id, position, instance_name, loaded_by) in &query {
+        let Some(instance_lock) = instance_container.get(instance_name) else {
             // the instance isn't even loaded by us, so we can safely delete the entity
             debug!(
                 "Despawned entity {entity:?} because it's in an instance that isn't loaded anymore"

azalea-protocol/src/read.rs

@@ -117,6 +117,13 @@ fn parse_frame(buffer: &mut Cursor<Vec<u8>>) -> Result<Box<[u8]>, FrameSplitterE
         // reset the inner vec once we've reached the end of the buffer so we don't keep
         // leaking memory
         buffer.get_mut().clear();
+
+        // we just cap the capacity to 64KB instead of resetting it to save some
+        // allocations.
+        // and the reason we bother capping it at all is to avoid wasting memory if we
+        // get a big packet once and then never again.
+        buffer.get_mut().shrink_to(1024 * 64);
+
         buffer.set_position(0);
     }
 

azalea/examples/testbot/commands/debug.rs

@@ -197,6 +197,8 @@ pub fn register(commands: &mut CommandDispatcher<Mutex<CommandSource>>) {
                 .unwrap();
             }
 
+            writeln!(report).unwrap();
+
             for (info, _) in ecs.iter_resources() {
                 writeln!(report, "Resource: {}", info.name()).unwrap();
                 writeln!(report, "- Size: {} bytes", info.layout().size()).unwrap();

azalea/examples/testbot/main.rs

@@ -57,14 +57,18 @@ async fn main() {
             Account::offline(username_or_email)
         };
 
-        let mut commands = CommandDispatcher::new();
-        register_commands(&mut commands);
-
-        builder = builder.add_account_with_state(account, State::new(args.clone(), commands));
+        builder = builder.add_account_with_state(account, State::new());
     }
 
+    let mut commands = CommandDispatcher::new();
+    register_commands(&mut commands);
+
     builder
         .join_delay(Duration::from_millis(100))
+        .set_swarm_state(SwarmState {
+            args,
+            commands: Arc::new(commands),
+        })
         .start(join_address)
         .await
         .unwrap();
@@ -102,17 +106,13 @@ pub enum BotTask {
 
 #[derive(Component, Clone, Default)]
 pub struct State {
-    pub args: Args,
-    pub commands: Arc<CommandDispatcher<Mutex<CommandSource>>>,
     pub killaura: bool,
     pub task: Arc<Mutex<BotTask>>,
 }
 
 impl State {
-    fn new(args: Args, commands: CommandDispatcher<Mutex<CommandSource>>) -> Self {
+    fn new() -> Self {
         Self {
-            args,
-            commands: Arc::new(commands),
             killaura: true,
             task: Arc::new(Mutex::new(BotTask::None)),
         }
@@ -120,9 +120,14 @@ impl State {
 }
 
 #[derive(Resource, Default, Clone)]
-struct SwarmState;
+struct SwarmState {
+    pub args: Args,
+    pub commands: Arc<CommandDispatcher<Mutex<CommandSource>>>,
+}
 
 async fn handle(bot: Client, event: azalea::Event, state: State) -> anyhow::Result<()> {
+    let swarm = bot.resource::<SwarmState>();
+
     match event {
         azalea::Event::Init => {
             bot.set_client_information(ClientInformation {
@@ -130,7 +135,7 @@ async fn handle(bot: Client, event: azalea::Event, state: State) -> anyhow::Resu
                 ..Default::default()
             })
             .await?;
-            if state.args.pathfinder_debug_particles {
+            if swarm.args.pathfinder_debug_particles {
                 bot.ecs
                     .lock()
                     .entity_mut(bot.entity)
@@ -141,7 +146,7 @@ async fn handle(bot: Client, event: azalea::Event, state: State) -> anyhow::Resu
             let (Some(username), content) = chat.split_sender_and_content() else {
                 return Ok(());
             };
-            if username != state.args.owner_username {
+            if username != swarm.args.owner_username {
                 return Ok(());
             }
 
@@ -153,7 +158,7 @@ async fn handle(bot: Client, event: azalea::Event, state: State) -> anyhow::Resu
                 content.strip_prefix('!').map(|s| s.to_owned())
             };
             if let Some(command) = command {
-                match state.commands.execute(
+                match swarm.commands.execute(
                     command,
                     Mutex::new(CommandSource {
                         bot: bot.clone(),

azalea/src/swarm/mod.rs

@@ -409,6 +409,7 @@ where
         {
             let mut ecs = ecs_lock.lock();
             ecs.insert_resource(swarm.clone());
+            ecs.insert_resource(self.swarm_state.clone());
             ecs.run_schedule(main_schedule_label);
             ecs.clear_trackers();
         }