Merge pull request #22 from griffi-gh/save-files

Save files

.gitignore

@@ -1,3 +1,5 @@
+.direnv
+
 # Generated by Cargo
 # will have compiled files and executables
 debug/
@@ -15,6 +17,7 @@ _src
 _visualizer.json
 
 *.kubi
+*.kbi
 
 /*_log*.txt
 /*.log
@@ -37,4 +40,4 @@ _visualizer.json
 
 /mods
 
-.direnv
+

Cargo.lock

@@ -1307,8 +1307,10 @@ dependencies = [
  "bincode",
  "bytemuck",
  "fastnoise-lite",
+ "flume",
  "glam",
  "hashbrown 0.14.5",
+ "log",
  "nohash-hasher",
  "num_enum",
  "nz",

Server.toml

@@ -4,6 +4,7 @@ max_clients = 32
 timeout_ms = 10000
 
 [world]
+file = "world.kubi"
 seed = 0xfeb_face_dead_cafe
 preheat_radius = 8
 

kubi-server/src/client.rs

@@ -50,7 +50,7 @@ pub fn sync_client_positions(
     };
 
     //log movement (annoying duh)
-    log::debug!("dbg: player moved id: {} coords: {} quat: {}", message.client_id, position, direction);
+    // log::debug!("dbg: player moved id: {} coords: {} quat: {}", message.client_id, position, direction);
 
     //Apply position to server-side client
     let mut trans = (&mut transforms).get(message.entity_id).unwrap();

kubi-server/src/config.rs

@@ -1,6 +1,6 @@
 use shipyard::{AllStoragesView, Unique};
 use serde::{Serialize, Deserialize};
-use std::{fs, net::SocketAddr};
+use std::{fs, net::SocketAddr, path::PathBuf};
 
 #[derive(Serialize, Deserialize)]
 pub struct ConfigTableServer {
@@ -12,6 +12,7 @@ pub struct ConfigTableServer {
 
 #[derive(Serialize, Deserialize)]
 pub struct ConfigTableWorld {
+  pub file: Option<PathBuf>,
   pub seed: u64,
   pub preheat_radius: u32,
 }

kubi-server/src/main.rs

@@ -1,5 +1,6 @@
-use shipyard::{IntoWorkload, Workload, WorkloadModificator, World};
+use shipyard::{IntoWorkload, SystemModificator, Workload, WorkloadModificator, World};
 use std::{thread, time::Duration};
+use kubi_shared::fixed_timestamp::{FixedTimestamp, init_fixed_timestamp_storage};
 
 mod util;
 mod config;
@@ -12,10 +13,11 @@ use config::read_config;
 use server::{bind_server, update_server, log_server_errors};
 use client::{init_client_maps, on_client_disconnect, sync_client_positions};
 use auth::authenticate_players;
-use world::{update_world, init_world};
+use world::{init_world, save::save_modified, update_world};
 
 fn initialize() -> Workload {
   (
+    init_fixed_timestamp_storage,
     read_config,
     bind_server,
     init_client_maps,
@@ -32,7 +34,10 @@ fn update() -> Workload {
       update_world,
       sync_client_positions,
       on_client_disconnect,
-    ).into_workload()
+    ).into_workload(),
+    save_modified
+      .into_workload()
+      .make_fixed(10000, 0),
   ).into_sequential_workload()
 }
 

kubi-server/src/world.rs

@@ -24,12 +24,13 @@ use crate::{
 
 pub mod chunk;
 pub mod tasks;
+pub mod save;
 
 use chunk::Chunk;
 
 use self::{
   tasks::{ChunkTaskManager, ChunkTask, ChunkTaskResponse, init_chunk_task_manager},
-  chunk::ChunkState
+  chunk::ChunkState,
 };
 
 #[derive(Unique, Default)]
@@ -106,7 +107,7 @@ fn process_chunk_requests(
       chunk.state = ChunkState::Loading;
       chunk.subscriptions.insert(message.client_id);
       chunk_manager.chunks.insert(chunk_position, chunk);
-      task_manager.spawn_task(ChunkTask::LoadChunk {
+      task_manager.run(ChunkTask::LoadChunk {
         position: chunk_position,
         seed: config.world.seed,
       });
@@ -249,7 +250,11 @@ fn process_block_queue(
     let Some(blocks) = &mut chunk.blocks else {
       return true
     };
-    blocks[block_position.x as usize][block_position.y as usize][block_position.z as usize] = item.block_type;
+    let block = &mut blocks[block_position.x as usize][block_position.y as usize][block_position.z as usize];
+    if item.block_type != *block {
+      *block = item.block_type;
+      chunk.data_modified = true;
+    }
     false
   });
   if initial_len != queue.queue.len() {
@@ -278,7 +283,7 @@ pub fn preheat_world(
         let mut chunk = Chunk::new();
         chunk.state = ChunkState::Loading;
         chunk_manager.chunks.insert(chunk_position, chunk);
-        task_manager.spawn_task(ChunkTask::LoadChunk {
+        task_manager.run(ChunkTask::LoadChunk {
           position: chunk_position,
           seed: config.world.seed,
         });
@@ -292,7 +297,7 @@ pub fn init_world() -> Workload {
     init_chunk_manager_and_block_queue.before_all(preheat_world),
     init_chunk_task_manager.before_all(preheat_world),
     preheat_world,
-  ).into_workload()
+  ).into_sequential_workload()
 }
 
 pub fn update_world() -> Workload {

kubi-server/src/world/chunk.rs

@@ -16,13 +16,16 @@ pub struct Chunk {
   pub state: ChunkState,
   pub blocks: Option<BlockData>,
   pub subscriptions: HashSet<ClientId, BuildNoHashHasher<ClientId>>,
+  pub data_modified: bool,
 }
+
 impl Chunk {
   pub fn new() -> Self {
     Self {
       state: ChunkState::Nothing,
       blocks: None,
       subscriptions: HashSet::with_capacity_and_hasher(4, BuildNoHashHasher::default()),
+      data_modified: false,
     }
   }
 }

kubi-server/src/world/save.rs

@@ -0,0 +1,43 @@
+use kubi_shared::data::{io_thread::IOThreadManager, open_local_save_file};
+use shipyard::{AllStoragesView, UniqueView, UniqueViewMut};
+use crate::config::ConfigTable;
+use super::{
+  tasks::{ChunkTask, ChunkTaskManager},
+  ChunkManager,
+};
+
+pub fn init_save_file(storages: &AllStoragesView) -> Option<IOThreadManager> {
+  let config = storages.borrow::<UniqueView<ConfigTable>>().unwrap();
+  if let Some(file_path) = &config.world.file {
+    log::info!("Initializing save file from {:?}", file_path);
+    let save = open_local_save_file(&file_path).unwrap();
+    Some(IOThreadManager::new(save))
+  } else {
+    log::warn!("No save file specified, world will not be saved");
+    None
+  }
+}
+
+pub fn save_modified(
+  mut chunks: UniqueViewMut<ChunkManager>,
+  ctm: UniqueView<ChunkTaskManager>,
+) {
+  log::info!("Saving...");
+  let mut amount_saved = 0;
+  for (position, chunk) in chunks.chunks.iter_mut() {
+    if chunk.data_modified {
+      let Some(data) = chunk.blocks.clone() else {
+        continue
+      };
+      ctm.run(ChunkTask::SaveChunk {
+        position: *position,
+        data: data,
+      });
+      chunk.data_modified = false;
+      amount_saved += 1;
+    }
+  }
+  if amount_saved > 0 {
+    log::info!("Queued {} chunks for saving", amount_saved);
+  }
+}

kubi-server/src/world/tasks.rs

@@ -4,16 +4,19 @@ use glam::IVec3;
 use rayon::{ThreadPool, ThreadPoolBuilder};
 use anyhow::Result;
 use kubi_shared::{
-  chunk::BlockData, 
-  worldgen::generate_world,
-  queue::QueuedBlock,
+  chunk::BlockData, data::io_thread::{IOCommand, IOResponse, IOThreadManager}, queue::QueuedBlock, worldgen::generate_world
 };
+use super::save::init_save_file;
 
 pub enum ChunkTask {
   LoadChunk {
     position: IVec3,
     seed: u64,
-  }
+  },
+  SaveChunk {
+    position: IVec3,
+    data: BlockData,
+  },
 }
 
 pub enum ChunkTaskResponse {
@@ -28,33 +31,74 @@ pub enum ChunkTaskResponse {
 pub struct ChunkTaskManager {
   channel: (Sender<ChunkTaskResponse>, Receiver<ChunkTaskResponse>),
   pool: ThreadPool,
+  iota: Option<IOThreadManager>,
 }
+
 impl ChunkTaskManager {
-  pub fn new() -> Result<Self> {
+  pub fn new(iota: Option<IOThreadManager>) -> Result<Self> {
     Ok(Self {
       channel: unbounded(),
-      pool: ThreadPoolBuilder::new().build()?
+      pool: ThreadPoolBuilder::new().build()?,
+      iota,
     })
   }
-  pub fn spawn_task(&self, task: ChunkTask) {
-    let sender = self.channel.0.clone();
-    self.pool.spawn(move || {
-      sender.send(match task {
-        ChunkTask::LoadChunk { position: chunk_position, seed } => {
-          //unwrap is fine because abort is not possible
-          let (blocks, queue) = generate_world(chunk_position, seed, None).unwrap();
-          ChunkTaskResponse::ChunkLoaded { chunk_position, blocks, queue }
+
+  pub fn run(&self, task: ChunkTask) {
+    match task {
+      ChunkTask::LoadChunk { position: chunk_position, seed } => {
+        // 1. Check if the chunk exists in the save file
+        if let ChunkTask::LoadChunk { position, .. } = &task {
+          if let Some(iota) = &self.iota {
+            if iota.chunk_exists(*position) {
+              iota.send(IOCommand::LoadChunk { position: *position });
+              return
+            }
+          }
         }
-      }).unwrap()
-    })
+
+        // 2. Generate the chunk if it doesn't exist
+        let sender = self.channel.0.clone();
+        self.pool.spawn(move || {
+          sender.send({
+            //unwrap is fine because abort is not possible
+            let (blocks, queue) = generate_world(chunk_position, seed, None).unwrap();
+            ChunkTaskResponse::ChunkLoaded { chunk_position, blocks, queue }
+          }).unwrap()
+        });
+      },
+      ChunkTask::SaveChunk { position, data } => {
+        // Save the chunk to the save file
+        if let Some(iota) = &self.iota {
+          iota.send(IOCommand::SaveChunk { position, data });
+        }
+      },
+    }
   }
+
   pub fn receive(&self) -> Option<ChunkTaskResponse> {
-    self.channel.1.try_recv().ok()
+    // Try to receive IO results first
+    // If there are none, try to receive worldgen results
+    self.iota.as_ref().map(|iota| {
+      iota.poll_single().map(|response| match response {
+        IOResponse::ChunkLoaded { position, data } => ChunkTaskResponse::ChunkLoaded {
+          chunk_position: position,
+          blocks: data.expect("chunk data exists in the header, but was not loaded"),
+          queue: Vec::with_capacity(0)
+        },
+        _ => panic!("Unexpected response from IO thread"),
+      })
+    }).flatten().or_else(|| {
+      self.channel.1.try_recv().ok()
+    })
   }
 }
 
 pub fn init_chunk_task_manager(
   storages: AllStoragesView
 ) {
-  storages.add_unique(ChunkTaskManager::new().expect("ChunkTaskManager Init failed"));
+  let iota = init_save_file(&storages);
+  storages.add_unique(
+    ChunkTaskManager::new(iota)
+      .expect("ChunkTaskManager Init failed")
+  );
 }

kubi-shared/Cargo.toml

@@ -14,6 +14,7 @@ serde = { version = "1.0", default-features = false, features = ["alloc", "deriv
 serde_with = "3.4"
 bincode = "1.3"
 anyhow = "1.0"
+flume = "0.11"
 fastnoise-lite = { version = "1.1", features = ["std", "f64"] }
 rand = { version = "0.8", default_features = false, features = ["std", "min_const_gen"] }
 rand_xoshiro = "0.6"
@@ -23,6 +24,7 @@ bytemuck = { version = "1.14", features = ["derive"] }
 static_assertions = "1.1"
 nz = "0.4"
 atomic = "0.6"
+log = "0.4"
 
 [features]
 default = []

kubi-shared/src/data.rs

@@ -1,7 +1,8 @@
 use std::{
-  fs::File,
   mem::size_of,
+  fs::{File, OpenOptions},
   io::{Read, Seek, SeekFrom, Write},
+  path::Path,
   borrow::Cow,
   sync::{Arc, RwLock}
 };
@@ -17,6 +18,8 @@ use crate::{
   chunk::{CHUNK_SIZE, BlockDataRef, BlockData}
 };
 
+pub mod io_thread;
+
 const SECTOR_SIZE: usize = CHUNK_SIZE * CHUNK_SIZE * CHUNK_SIZE * size_of::<Block>();
 const RESERVED_SIZE: usize = 1048576; //~1mb (16 sectors assuming 32x32x32 world of 1byte blocks)
 const RESERVED_SECTOR_COUNT: usize = RESERVED_SIZE / SECTOR_SIZE;
@@ -47,19 +50,19 @@ impl Default for WorldSaveDataHeader {
   }
 }
 
+pub type SharedHeader = Arc<RwLock<WorldSaveDataHeader>>;
+
 #[derive(Unique)]
 pub struct WorldSaveFile {
   pub file: File,
-  pub header: WorldSaveDataHeader,
+  pub header: SharedHeader,
 }
 
-pub type SharedSaveFile = Arc<RwLock<WorldSaveFile>>;
-
 impl WorldSaveFile {
   pub fn new(file: File) -> Self {
     WorldSaveFile {
       file,
-      header: WorldSaveDataHeader::default()
+      header: Arc::new(RwLock::new(WorldSaveDataHeader::default())),
     }
   }
 
@@ -76,7 +79,7 @@ impl WorldSaveFile {
     }
 
     let limit = (RESERVED_SIZE - SUBHEADER_SIZE) as u64;
-    self.header = bincode::deserialize_from((&self.file).take(limit))?;
+    *self.header.write().unwrap() = bincode::deserialize_from((&self.file).take(limit))?;
 
     Ok(())
   }
@@ -88,7 +91,7 @@ impl WorldSaveFile {
     //XXX: this can cause the header to destroy chunk data (if it's WAY too long)
     //     read has checks against this, but write doesn't
     //     1mb is pretty generous tho, so it's not a *big* deal
-    bincode::serialize_into(&self.file, &self.header)?;
+    bincode::serialize_into(&self.file, &*self.header.read().unwrap())?;
     Ok(())
   }
 
@@ -102,19 +105,28 @@ impl WorldSaveFile {
     Ok(())
   }
 
-  fn allocate_sector(&mut self) -> u32 {
-    let value = self.header.sector_count + 1;
-    self.header.sector_count += 1;
-    value
-  }
+  // fn allocate_sector(&mut self) -> u32 {
+  //   let mut lock = self.header.write().unwrap();
+  //   let value = lock.sector_count + 1;
+  //   lock.sector_count += 1;
+  //   value
+  // }
 
   pub fn save_chunk(&mut self, position: IVec3, data: &BlockDataRef) -> Result<()> {
+    let mut header_lock = self.header.write().unwrap();
+
     let mut header_modified = false;
-    let sector = self.header.chunk_map.get(&position).copied().unwrap_or_else(|| {
+    let sector = header_lock.chunk_map.get(&position).copied().unwrap_or_else(|| {
       header_modified = true;
-      self.allocate_sector()
+      let sector = header_lock.sector_count;
+      header_lock.sector_count += 1;
+      header_lock.chunk_map.insert(position, sector);
+      sector
+      // self.allocate_sector()
     });
 
+    drop(header_lock);
+
     let offset = sector as u64 * SECTOR_SIZE as u64;
 
     const_assert_eq!(size_of::<Block>(), 1);
@@ -136,11 +148,11 @@ impl WorldSaveFile {
   }
 
   pub fn chunk_exists(&self, position: IVec3) -> bool {
-    self.header.chunk_map.contains_key(&position)
+    self.header.read().unwrap().chunk_map.contains_key(&position)
   }
 
   pub fn load_chunk(&mut self, position: IVec3) -> Result<Option<BlockData>> {
-    let Some(&sector) = self.header.chunk_map.get(&position) else {
+    let Some(&sector) = self.header.read().unwrap().chunk_map.get(&position) else {
       return Ok(None);
     };
 
@@ -166,4 +178,26 @@ impl WorldSaveFile {
 
     Ok(Some(data))
   }
+
+  pub fn get_shared_header(&self) -> SharedHeader {
+    Arc::clone(&self.header)
+  }
 }
+
+/// Utility function to open a local save file, creating it if it doesn't exist
+pub fn open_local_save_file(path: &Path) -> Result<WorldSaveFile> {
+  let mut save_file = WorldSaveFile::new({
+    OpenOptions::new()
+      .read(true)
+      .write(true)
+      .create(true)
+      .open(path)?
+  });
+  if save_file.file.metadata().unwrap().len() == 0 {
+    save_file.initialize()?;
+  } else {
+    save_file.load_data()?;
+  }
+  Ok(save_file)
+}
+

kubi-shared/src/data/io_thread.rs

@@ -0,0 +1,249 @@
+use glam::IVec3;
+use flume::{Receiver, Sender, TryIter};
+use shipyard::Unique;
+use crate::chunk::BlockData;
+use super::{SharedHeader, WorldSaveFile};
+
+// Maximum amount of chunks to save in a single batch before checking if there are any pending read requests
+// may be broken, so currently disabled
+const MAX_SAVE_BATCH_SIZE: usize = usize::MAX;
+
+pub enum IOCommand {
+  SaveChunk {
+    position: IVec3,
+    data: BlockData,
+  },
+
+  /// Load a chunk from the disk and send it to the main thread
+  LoadChunk {
+    position: IVec3,
+  },
+
+  /// Process all pending write commands and make the thread end itself
+  /// LoadChunk commands will be ignored after this command is received
+  Kys,
+}
+
+#[derive(Debug)]
+pub enum IOResponse {
+  /// A chunk has been loaded from the disk
+  /// Or not, in which case the data will be None
+  /// and chunk should be generated
+  ChunkLoaded {
+    position: IVec3,
+    data: Option<BlockData>,
+  },
+
+  /// The IO thread has been terminated
+  Terminated,
+}
+
+struct IOThreadContext {
+  tx: Sender<IOResponse>,
+  rx: Receiver<IOCommand>,
+  save: WorldSaveFile,
+  save_queue: Vec<(IVec3, BlockData)>,
+}
+
+//TODO: Implement proper error handling (I/O errors are rlly common)
+
+impl IOThreadContext {
+  /// Should be called ON the IO thread
+  ///
+  /// Initializes the IO thread context, opening the file at the given path
+  /// If there's an error opening the file, the thread will panic (TODO: handle this more gracefully)
+  pub fn initialize(
+    tx: Sender<IOResponse>,
+    rx: Receiver<IOCommand>,
+    save: WorldSaveFile,
+  ) -> Self {
+    // save.load_data().unwrap();
+    let save_queue = Vec::new();
+    Self { tx, rx, save, save_queue }
+  }
+
+  pub fn run(mut self) {
+    loop {
+      // because were waiting for the next command, we can't process the save_queue
+      // which breaks batching, so we need to check if there are any pending save requests
+      // and if there are, use non-blocking recv to give them a chance to be processed
+      'rx: while let Some(command) = {
+        if self.save_queue.len() > 0 {
+          self.rx.try_recv().ok()
+        } else {
+          self.rx.recv().ok()
+        }
+      } {
+        match command {
+          IOCommand::SaveChunk { position, data } => {
+            // if chunk already has a save request, overwrite it
+            for (pos, old_data) in self.save_queue.iter_mut() {
+              if *pos == position {
+                *old_data = data;
+                continue 'rx;
+              }
+            }
+            // if not, save to the queue
+            self.save_queue.push((position, data));
+            //log::trace!("amt of unsaved chunks: {}", self.save_queue.len());
+          }
+          IOCommand::LoadChunk { position } => {
+            // HOLD ON
+            // first check if the chunk is already in the save queue
+            // if it is, send it and continue
+            // (NOT doing this WILL result in data loss if the user returns to the chunk too quickly)
+            for (pos, data) in self.save_queue.iter() {
+              if *pos == position {
+                self.tx.send(IOResponse::ChunkLoaded { position, data: Some(data.clone()) }).unwrap();
+                continue 'rx;
+              }
+            }
+            let data = self.save.load_chunk(position).unwrap();
+            self.tx.send(IOResponse::ChunkLoaded { position, data }).unwrap();
+          }
+          IOCommand::Kys => {
+            // Process all pending write commands
+            log::info!("info: queue has {} chunks", self.save_queue.len());
+            let mut saved_amount = 0;
+            for (pos, data) in self.save_queue.drain(..) {
+              self.save.save_chunk(pos, &data).unwrap();
+              saved_amount += 1;
+            }
+            log::debug!("now, moving on to the rx queue...");
+            for cmd in self.rx.try_iter() {
+              let IOCommand::SaveChunk { position, data } = cmd else {
+                continue;
+              };
+              self.save.save_chunk(position, &data).unwrap();
+              saved_amount += 1;
+            }
+            log::info!("saved {} chunks on exit", saved_amount);
+            self.tx.send(IOResponse::Terminated).unwrap();
+            return;
+          }
+        }
+      }
+      // between every betch of requests, check if there are any pending save requests
+      if self.save_queue.len() > 0 {
+        let will_drain = MAX_SAVE_BATCH_SIZE.min(self.save_queue.len());
+        log::info!("saving {}/{} chunks with batch size {}...", will_drain, self.save_queue.len(), MAX_SAVE_BATCH_SIZE);
+        for (pos, data) in self.save_queue.drain(..will_drain) {
+          self.save.save_chunk(pos, &data).unwrap();
+        }
+      }
+    }
+  }
+}
+
+pub struct IOSingleThread {
+  tx: Sender<IOCommand>,
+  rx: Receiver<IOResponse>,
+  handle: std::thread::JoinHandle<()>,
+  header: SharedHeader,
+}
+
+impl IOSingleThread {
+  pub fn spawn(save: WorldSaveFile) -> Self {
+    // Create channels
+    let (command_tx, command_rx) = flume::unbounded();
+    let (response_tx, response_rx) = flume::unbounded();
+
+    // Grab a handle to the header
+    let header = save.get_shared_header();
+
+    // Spawn the thread
+    let builder = std::thread::Builder::new()
+      .name("io-thread".into());
+    let handle = builder.spawn(move || {
+      let context = IOThreadContext::initialize(response_tx, command_rx, save);
+      context.run();
+    }).unwrap();
+
+    IOSingleThread {
+      tx: command_tx,
+      rx: response_rx,
+      handle,
+      header,
+    }
+  }
+
+  /// Send a command to the IO thread
+  pub fn send(&self, cmd: IOCommand) {
+    self.tx.send(cmd).unwrap();
+  }
+
+  /// Poll the IO thread for a single response (non-blocking)
+  pub fn poll_single(&self) -> Option<IOResponse> {
+    self.rx.try_recv().ok()
+  }
+
+  /// Poll the IO thread for responses (non-blocking)
+  pub fn poll(&self) -> TryIter<IOResponse> {
+    self.rx.try_iter()
+  }
+
+  /// Signal the IO thread to process the remaining requests and wait for it to terminate
+  pub fn stop_sync(&self) {
+    log::debug!("Stopping IO thread (sync)");
+
+    // Tell the thread to terminate and wait for it to finish
+    self.tx.send(IOCommand::Kys).unwrap();
+    while !matches!(self.rx.recv().unwrap(), IOResponse::Terminated) {}
+
+    // HACK "we have .join at home"
+    while !self.handle.is_finished() {}
+
+    log::debug!("IO thread stopped"); //almost lol
+  }
+
+  /// Same as stop_sync but doesn't wait for the IO thread to terminate
+  pub fn stop_async(&self) {
+    log::debug!("Stopping IO thread (async)");
+    self.tx.send(IOCommand::Kys).unwrap();
+  }
+
+  pub fn chunk_exists(&self, position: IVec3) -> bool {
+    self.header.read().unwrap().chunk_map.contains_key(&position)
+  }
+}
+
+impl Drop for IOSingleThread {
+  fn drop(&mut self) {
+    log::trace!("IOSingleThread dropped, about to sync unsaved data...");
+    self.stop_sync();
+  }
+}
+
+
+/// This is a stub for future implemntation that may use multiple IO threads
+#[derive(Unique)]
+pub struct IOThreadManager {
+  thread: IOSingleThread,
+}
+
+impl IOThreadManager {
+  pub fn new(save: WorldSaveFile) -> Self {
+    Self {
+      thread: IOSingleThread::spawn(save)
+    }
+  }
+
+  pub fn send(&self, cmd: IOCommand) {
+    self.thread.send(cmd);
+  }
+
+  pub fn poll_single(&self) -> Option<IOResponse> {
+    self.thread.poll_single()
+  }
+
+  pub fn poll(&self) -> TryIter<IOResponse> {
+    self.thread.poll()
+  }
+
+  pub fn chunk_exists(&self, position: IVec3) -> bool {
+    self.thread.chunk_exists(position)
+  }
+}
+
+// i think im a girl :3 (noone will ever read this right? :p)
+

kubi-shared/src/lib.rs

@@ -8,3 +8,4 @@ pub mod entity;
 pub mod player;
 pub mod queue;
 pub mod data;
+pub mod fixed_timestamp;

kubi/src/init.rs

@@ -5,33 +5,25 @@ use crate::{
   networking::{GameType, ServerAddress},
   state::{GameState, NextState}
 };
-use kubi_shared::data::WorldSaveFile;
-
-fn open_local_save_file(path: &Path) -> Result<WorldSaveFile> {
-  let mut save_file = WorldSaveFile::new({
-    OpenOptions::new()
-      .read(true)
-      .write(true)
-      .open("world.kbi")?
-  });
-  if save_file.file.metadata().unwrap().len() == 0 {
-    save_file.initialize()?;
-  } else {
-    save_file.load_data()?;
-  }
-  Ok(save_file)
-}
+use kubi_shared::data::{io_thread::IOThreadManager, WorldSaveFile, open_local_save_file};
 
 pub fn initialize_from_args(
   all_storages: AllStoragesView,
 ) {
+  // If an address is provided, we're in multiplayer mode (the first argument is the address)
+  // Otherwise, we're in singleplayer mode and working with local stuff
   let args: Vec<String> = env::args().collect();
   if args.len() > 1 {
+    // Parse the address and switch the state to connecting
     let address = args[1].parse::<SocketAddr>().expect("invalid address");
     all_storages.add_unique(GameType::Muliplayer);
     all_storages.add_unique(ServerAddress(address));
     all_storages.borrow::<UniqueViewMut<NextState>>().unwrap().0 = Some(GameState::Connecting);
   } else {
+    // Open the local save file
+    let save_file = open_local_save_file(Path::new("./world.kubi")).expect("failed to open save file");
+    all_storages.add_unique(IOThreadManager::new(save_file));
+    // Switch the state and kick off the world loading
     all_storages.add_unique(GameType::Singleplayer);
     all_storages.borrow::<UniqueViewMut<NextState>>().unwrap().0 = Some(GameState::LoadingWorld);
   }

kubi/src/lib.rs

@@ -23,7 +23,9 @@ use winit::{
 use glam::vec3;
 use std::time::Instant;
 
+//TODO remove these re-exports
 pub(crate) use kubi_shared::transform;
+pub(crate) use kubi_shared::fixed_timestamp;
 
 mod ui;
 pub(crate) use ui::{
@@ -51,17 +53,12 @@ pub(crate) mod hui_integration;
 pub(crate) mod networking;
 pub(crate) mod init;
 pub(crate) mod color;
-pub(crate) mod fixed_timestamp;
 pub(crate) mod filesystem;
 pub(crate) mod client_physics;
 pub(crate) mod chat;
 
 use world::{
-  init_game_world,
-  loading::update_loaded_world_around_player,
-  raycast::update_raycasts,
-  queue::apply_queued_blocks,
-  tasks::ChunkTaskManager,
+  init_game_world, loading::{save_on_exit, update_loaded_world_around_player}, queue::apply_queued_blocks, raycast::update_raycasts, tasks::ChunkTaskManager
 };
 use player::{spawn_player, MainPlayer};
 use prefabs::load_prefabs;
@@ -157,7 +154,6 @@ fn update() -> Workload {
     kubi_ui_end,
     update_state,
     exit_on_esc,
-    disconnect_on_exit.run_if(is_multiplayer),
     update_rendering_late,
   ).into_sequential_workload()
 }
@@ -183,6 +179,13 @@ fn after_render() -> Workload {
   ).into_sequential_workload()
 }
 
+fn on_exit() -> Workload{
+  (
+    disconnect_on_exit.run_if(is_multiplayer),
+    save_on_exit.run_if(is_singleplayer),
+  ).into_sequential_workload().run_if(is_ingame_or_loading)
+}
+
 #[cfg(all(windows, not(debug_assertions)))]
 fn attach_console() {
   use winapi::um::wincon::{AttachConsole, ATTACH_PARENT_PROCESS};
@@ -243,6 +246,7 @@ pub fn kubi_main(
   world.add_workload(update);
   //world.add_workload(render);
   world.add_workload(after_render);
+  world.add_workload(on_exit);
 
   //Save _visualizer.json
   #[cfg(feature = "generate_visualizer_data")] {
@@ -350,6 +354,11 @@ pub fn kubi_main(
           window_target.exit();
         }
       },
+
+      Event::LoopExiting => {
+        world.run_workload(on_exit).unwrap();
+      },
+
       _ => (),
     };
   }).unwrap();

kubi/src/networking.rs

@@ -159,19 +159,15 @@ pub fn update_networking_late() -> Workload {
 }
 
 pub fn disconnect_on_exit(
-  exit: UniqueView<RequestExit>,
   mut client: UniqueViewMut<UdpClient>,
 ) {
-  //TODO check if this works
-  if exit.0 {
-    if client.0.is_active() {
-      client.0.flush();
-      client.0.disconnect();
-      while client.0.is_active() { client.0.step().for_each(|_|()); }
-      log::info!("Client disconnected");
-    } else {
-      log::info!("Client inactive")
-    }
+  if client.0.is_active() {
+    client.0.flush();
+    client.0.disconnect();
+    while client.0.is_active() { client.0.step().for_each(|_|()); }
+    log::info!("Client disconnected");
+  } else {
+    log::info!("Client inactive")
   }
 }
 

kubi/src/networking/world.rs

@@ -37,7 +37,7 @@ pub fn inject_network_responses_into_manager_queue(
       let ServerToClientMessage::ChunkResponse {
         chunk, data, queued
       } = packet else { unreachable!() };
-      manager.add_sussy_response(ChunkTaskResponse::LoadedChunk {
+      manager.add_sussy_response(ChunkTaskResponse::ChunkWorldgenDone {
         position: chunk,
         chunk_data: data,
         queued

kubi/src/world.rs

@@ -62,10 +62,10 @@ impl ChunkStorage {
   }
 }
 
-#[derive(Unique)]
-pub struct WorldInfo {
-  pub seed: u32,
-}
+// #[derive(Unique)]
+// pub struct WorldInfo {
+//   pub seed: u32,
+// }
 
 #[derive(Default, Unique)]
 pub struct ChunkMeshStorage {

kubi/src/world/chunk.rs

@@ -57,6 +57,7 @@ pub struct Chunk {
   pub desired_state: DesiredChunkState,
   pub abortion: Option<Arc<Atomic<AbortState>>>,
   pub mesh_dirty: bool,
+  pub data_modified: bool,
 }
 
 impl Chunk {
@@ -69,6 +70,7 @@ impl Chunk {
       desired_state: Default::default(),
       abortion: None,
       mesh_dirty: false,
+      data_modified: false,
     }
   }
 }

kubi/src/world/loading.rs

@@ -1,14 +1,18 @@
 use std::sync::Arc;
 use atomic::{Atomic, Ordering};
 use glam::{IVec3, ivec3};
-use kubi_shared::{networking::{channels::Channel, messages::ClientToServerMessage}, worldgen::AbortState};
+use kubi_shared::{
+  data::io_thread::{IOCommand, IOResponse, IOThreadManager},
+  networking::{channels::Channel, messages::ClientToServerMessage},
+  worldgen::AbortState,
+};
 use shipyard::{View, UniqueView, UniqueViewMut, IntoIter, Workload, IntoWorkload, NonSendSync, track};
 use uflow::SendMode;
 use wgpu::util::DeviceExt;
 use crate::{
   networking::UdpClient,
   player::MainPlayer,
-  rendering::{world::ChunkVertex, BufferPair, Renderer},
+  rendering::{BufferPair, Renderer},
   settings::GameSettings,
   state::GameState,
   transform::Transform,
@@ -16,10 +20,12 @@ use crate::{
 use super::{
   ChunkStorage, ChunkMeshStorage,
   chunk::{Chunk, DesiredChunkState, CHUNK_SIZE, ChunkMesh, CurrentChunkState, ChunkData},
-  tasks::{ChunkTaskManager, ChunkTaskResponse, ChunkTask}, 
+  tasks::{ChunkTaskManager, ChunkTaskResponse, ChunkTask},
   queue::BlockUpdateQueue,
 };
 
+const WORLD_SEED: u64 = 0xfeb_face_dead_cafe;
+
 const MAX_CHUNK_OPS_INGAME: usize = 8;
 const MAX_CHUNK_OPS: usize = 32;
 
@@ -92,6 +98,7 @@ pub fn update_chunks_if_player_moved(
 
 fn process_state_changes(
   task_manager: UniqueView<ChunkTaskManager>,
+  io: Option<UniqueView<IOThreadManager>>,
   mut udp_client: Option<UniqueViewMut<UdpClient>>,
   mut world: UniqueViewMut<ChunkStorage>,
   mut vm_meshes: NonSendSync<UniqueViewMut<ChunkMeshStorage>>,
@@ -135,7 +142,7 @@ fn process_state_changes(
         chunk.current_state,
         CurrentChunkState::Loaded | CurrentChunkState::CalculatingMesh,
       ) => {
-        chunk.block_data = None;
+        // chunk.block_data = None; //HACK when downgrading, keep the data so we can save it
         chunk.current_state = CurrentChunkState::Nothing;
       },
 
@@ -184,18 +191,38 @@ fn process_state_changes(
             SendMode::Reliable
           );
         } else {
-          let atomic = Arc::new(Atomic::new(AbortState::Continue));
-          task_manager.spawn_task(ChunkTask::LoadChunk {
-            seed: 0xbeef_face_dead_cafe,
-            position,
-            abortion: Some(Arc::clone(&atomic)),
-          });
-          abortion = Some(atomic);
+
+          // If the chunk exists in the save file (and save file is there in the first place),
+          // ... we'll try to load it
+          // Otherwise, we'll run worldgen
+
+          let mut should_run_worldgen = true;
+
+          if let Some(io) = &io {
+            if io.chunk_exists(position) {
+              // Try to load the chunk from the save file
+              // In case that fails, we will run worldgen once the IO thread responds
+              io.send(IOCommand::LoadChunk { position });
+              should_run_worldgen = false;
+            }
+          }
+
+          if should_run_worldgen {
+            let atomic = Arc::new(Atomic::new(AbortState::Continue));
+            task_manager.spawn_task(ChunkTask::ChunkWorldgen {
+              seed: WORLD_SEED,
+              position,
+              abortion: Some(Arc::clone(&atomic)),
+            });
+            abortion = Some(atomic);
+          }
         }
+
         //Update chunk state
         let chunk = world.chunks.get_mut(&position).unwrap();
         chunk.current_state = CurrentChunkState::Loading;
         chunk.abortion = abortion;
+
         // ===========
         //log::trace!("Started loading chunk {position}");
       },
@@ -254,7 +281,29 @@ fn process_state_changes(
         return false
       }
 
-      //HACK, since save files are not implemented, just unload immediately
+      // If in singleplayer and have an open save file, we need to save the chunk to the disk
+
+      // ==========================================================
+      //TODO IMPORTANT: WAIT FOR CHUNK TO FINISH SAVING FIRST BEFORE TRANSITIONING TO UNLOADED
+      // OTHERWISE WE WILL LOSE THE SAVE DATA IF THE USER COMES BACK TO THE CHUNK TOO QUICKLY
+      // ==========================================================
+      //XXX: CHECK IF WE REALLY NEED THIS OR IF WE CAN JUST KILL THE CHUNK RIGHT AWAY
+      //CHANGES TO CHUNK SAVING LOGIC SHOULD HAVE MADE THE ABOVE COMMENT OBSOLETE
+
+      if let Some(io) = &io {
+        if let Some(block_data) = &chunk.block_data {
+          // Only save the chunk if it has been modified
+          if chunk.data_modified {
+            // log::debug!("issue save command");
+            chunk.data_modified = false;
+            io.send(IOCommand::SaveChunk {
+              position,
+              data: block_data.blocks.clone(),
+            });
+          }
+        }
+      }
+
       return false
     }
     true
@@ -264,6 +313,7 @@ fn process_state_changes(
 
 fn process_completed_tasks(
   task_manager: UniqueView<ChunkTaskManager>,
+  io: Option<UniqueView<IOThreadManager>>,
   mut world: UniqueViewMut<ChunkStorage>,
   mut meshes: NonSendSync<UniqueViewMut<ChunkMeshStorage>>,
   renderer: UniqueView<Renderer>,
@@ -271,9 +321,69 @@ fn process_completed_tasks(
   mut queue: UniqueViewMut<BlockUpdateQueue>,
 ) {
   let mut ops: usize = 0;
-  while let Some(res) = task_manager.receive() {
+
+  //TODO reduce code duplication between loaded/generated chunks
+
+  // Process IO first
+  if let Some(io) = &io {
+    for response in io.poll() {
+      let IOResponse::ChunkLoaded { position, data } = response else {
+        //TODO this is bad
+        panic!("Unexpected IO response: {:?}", response);
+      };
+
+      //check if chunk exists
+      let Some(chunk) = world.chunks.get_mut(&position) else {
+        log::warn!("LOADED blocks data discarded: chunk doesn't exist");
+        continue
+      };
+
+      //we cannot have abortion here but just in case, reset it
+      chunk.abortion = None;
+
+      //check if chunk still wants it
+      if !matches!(chunk.desired_state, DesiredChunkState::Loaded | DesiredChunkState::Rendered) {
+        log::warn!("LOADED block data discarded: state undesirable: {:?}", chunk.desired_state);
+        continue
+      }
+
+      // check if we actually got the data
+      if let Some(data) = data {
+        // If we did get the data, yay :3
+        chunk.block_data = Some(ChunkData {
+          blocks: data
+        });
+        chunk.current_state = CurrentChunkState::Loaded;
+      } else {
+        // If we didn't get the data, we need to run worldgen
+        // XXX: will this ever happen? we should always have the data in the save file
+        let atomic = Arc::new(Atomic::new(AbortState::Continue));
+        task_manager.spawn_task(ChunkTask::ChunkWorldgen {
+          seed: WORLD_SEED,
+          position,
+          abortion: Some(Arc::clone(&atomic)),
+        });
+        chunk.abortion = Some(atomic);
+      }
+
+      ops += 1;
+    }
+
+    //return early if we've reached the limit
+    if ops >= match *state {
+      GameState::InGame => MAX_CHUNK_OPS_INGAME,
+      _ => MAX_CHUNK_OPS,
+    } { return }
+    // XXX: this will completely skip polling the task manager if we've reached the limit
+    //      this is probably fine, but it might be worth revisiting later
+  }
+
+  for res in task_manager.poll() {
     match res {
-      ChunkTaskResponse::LoadedChunk { position, chunk_data, mut queued } => {
+      ChunkTaskResponse::ChunkWorldgenDone { position, chunk_data, mut queued } => {
+        //TODO this can fuck shit up really badly if io op gets overwritten by worldgen chunk
+        //TODO only accept if loading stage, not loaded
+
         //If unwanted chunk is already loaded
         //It would be ~~...unethical~~ impossible to abort the operation at this point
         //Instead, we'll just throw it away
@@ -308,7 +418,7 @@ fn process_completed_tasks(
         //increase ops counter
         ops += 1;
       },
-      ChunkTaskResponse::GeneratedMesh {
+      ChunkTaskResponse::GenerateMeshDone {
         position,
         vertices, indices,
         trans_vertices, trans_indices,
@@ -392,3 +502,20 @@ fn process_completed_tasks(
     } { break }
   }
 }
+
+/// Save all modified chunks to the disk
+pub fn save_on_exit(
+  io: UniqueView<IOThreadManager>,
+  world: UniqueView<ChunkStorage>,
+) {
+  for (&position, chunk) in &world.chunks {
+    if let Some(block_data) = &chunk.block_data {
+      if chunk.data_modified {
+        io.send(IOCommand::SaveChunk {
+          position,
+          data: block_data.blocks.clone(),
+        });
+      }
+    }
+  }
+}

kubi/src/world/queue.rs

@@ -22,11 +22,15 @@ pub fn apply_queued_blocks(
       if event.soft && *block != Block::Air {
         return false
       }
+      if event.block_type == *block {
+        return false
+      }
       *block = event.block_type;
       //mark chunk as dirty
       let (chunk_pos, block_pos) = ChunkStorage::to_chunk_coords(event.position);
       let chunk = world.chunks.get_mut(&chunk_pos).expect("This error should never happen, if it does then something is super fucked up and the whole project needs to be burnt down.");
       chunk.mesh_dirty = true;
+      chunk.data_modified = true;
       //If block pos is close to the border, some neighbors may be dirty!
       const DIRECTIONS: [IVec3; 6] = [
         ivec3(1,  0,  0),

kubi/src/world/tasks.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 use atomic::Atomic;
-use flume::{Sender, Receiver};
+use flume::{Receiver, Sender, TryIter};
 use glam::IVec3;
 use kubi_shared::{queue::QueuedBlock, worldgen::AbortState};
 use shipyard::Unique;
@@ -13,7 +13,7 @@ use super::{
 use crate::rendering::world::ChunkVertex;
 
 pub enum ChunkTask {
-  LoadChunk {
+  ChunkWorldgen {
     seed: u64,
     position: IVec3,
     abortion: Option<Arc<Atomic<AbortState>>>,
@@ -23,13 +23,14 @@ pub enum ChunkTask {
     data: MeshGenData
   }
 }
+
 pub enum ChunkTaskResponse {
-  LoadedChunk {
+  ChunkWorldgenDone {
     position: IVec3,
     chunk_data: BlockData,
     queued: Vec<QueuedBlock>
   },
-  GeneratedMesh {
+  GenerateMeshDone {
     position: IVec3,
     vertices: Vec<ChunkVertex>,
     indices: Vec<u32>,
@@ -43,6 +44,7 @@ pub struct ChunkTaskManager {
   channel: (Sender<ChunkTaskResponse>, Receiver<ChunkTaskResponse>),
   pool: ThreadPool,
 }
+
 impl ChunkTaskManager {
   pub fn new() -> Self {
     Self {
@@ -50,11 +52,17 @@ impl ChunkTaskManager {
       pool: ThreadPoolBuilder::new().num_threads(4).build().unwrap()
     }
   }
+
+  //TODO get rid of add_sussy_response
+
+  /// Add a response to the queue, to be picked up by the main thread
+  /// Used by the multiplayer netcode, a huge hack
   pub fn add_sussy_response(&self, response: ChunkTaskResponse) {
     // this WILL get stuck if the channel is bounded
     // don't make the channel bounded ever
     self.channel.0.send(response).unwrap()
   }
+
   pub fn spawn_task(&self, task: ChunkTask) {
     let sender = self.channel.0.clone();
     self.pool.spawn(move || {
@@ -64,23 +72,29 @@ impl ChunkTaskManager {
             (vertices, indices),
             (trans_vertices, trans_indices),
           ) = generate_mesh(position, data);
-          ChunkTaskResponse::GeneratedMesh {
+          ChunkTaskResponse::GenerateMeshDone {
             position,
             vertices, indices,
             trans_vertices, trans_indices,
           }
         },
-        ChunkTask::LoadChunk { position, seed, abortion } => {
+        ChunkTask::ChunkWorldgen { position, seed, abortion } => {
           let Some((chunk_data, queued)) = generate_world(position, seed, abortion) else {
             log::warn!("aborted operation");
             return
           };
-          ChunkTaskResponse::LoadedChunk { position, chunk_data, queued }
+          ChunkTaskResponse::ChunkWorldgenDone { position, chunk_data, queued }
         }
       });
     });
   }
+
+  #[deprecated(note = "use poll instead")]
   pub fn receive(&self) -> Option<ChunkTaskResponse> {
     self.channel.1.try_recv().ok()
   }
+
+  pub fn poll(&self) -> TryIter<ChunkTaskResponse> {
+    self.channel.1.try_iter()
+  }
 }