feat: merge branch 'client-instance' into dev

reworked internal client API, added initial workspace concepts, split
cursor and buffer rpc services, added static instance with internal
mutability

Cargo.toml

@@ -13,7 +13,7 @@ name = "codemp"
 # core
 tracing = "0.1"
 tonic = { version = "0.9", features = ["tls", "tls-roots"] }
-prost = "0.11.8"
+prost = { version = "0.11.8", optional = true }
 md5 = "0.7.0"
 uuid = { version = "1.3.1", features = ["v4"] }
 operational-transform = { version = "0.6", features = ["serde"] }
@@ -23,6 +23,12 @@ serde = { version = "1", optional = false }
 serde_json = { version = "1", optional = false }
 tracing-subscriber = { version = "0.3", optional = true }
 similar = { version = "2.2", features = ["inline"] }
+lazy_static = { version = "1.4", optional = true }
 
 [build-dependencies]
 tonic-build = "0.9"
+
+[features]
+default = ["proto", "static"]
+proto   = ["dep:prost"]
+static  = ["dep:lazy_static"]

build.rs

@@ -1,4 +1,5 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
 	tonic_build::compile_protos("proto/buffer.proto")?;
+	tonic_build::compile_protos("proto/cursor.proto")?;
 	Ok(())
 }

client/vscode/src/lib.rs

@@ -3,9 +3,13 @@ use std::sync::Arc;
 use neon::prelude::*;
 use once_cell::sync::OnceCell;
 use codemp::{
-	controller::{cursor::{CursorSubscriber, CursorControllerHandle}, buffer::{OperationControllerHandle, OperationControllerSubscriber}},
+	cursor::controller::{CursorSubscriber, CursorControllerHandle},
-	client::CodempClient,
+	buffer::{
-	proto::buffer_client::BufferClient, factory::OperationFactory,
+		controller::{OperationControllerHandle, OperationControllerSubscriber},
+		client::CodempClient,
+		factory::OperationFactory,
+	},
+	proto::buffer_client::BufferClient, 
 };
 use codemp::tokio::{runtime::Runtime, sync::Mutex};
 
@@ -75,7 +79,7 @@ fn create_client(mut cx: FunctionContext) -> JsResult<JsPromise> {
 	let channel = cx.channel();
 
 	runtime(&mut cx)?.spawn(async move {
-		match rc.lock().await.create(path, content).await {
+		match rc.lock().await.create(&path, content.as_deref()).await {
 			Ok(accepted) => deferred.settle_with(&channel, move |mut cx| Ok(cx.boolean(accepted))),
 			Err(e) => deferred.settle_with(&channel, move |mut cx| cx.throw_error::<String, neon::handle::Handle<JsString>>(e.to_string())),
 		}
@@ -123,7 +127,7 @@ fn attach_client(mut cx: FunctionContext) -> JsResult<JsPromise> {
 	let channel = cx.channel();
 
 	runtime(&mut cx)?.spawn(async move {
-		match rc.lock().await.attach(path).await {
+		match rc.lock().await.attach(&path).await {
 			Ok(controller) => {
 				deferred.settle_with(&channel, move |mut cx| {
 					let obj = cx.empty_object();
@@ -183,7 +187,7 @@ fn callback_operation(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 	let boxed : Handle<JsBox<OperationControllerJs>> = this.get(&mut cx, "boxed")?;
 	let callback = Arc::new(cx.argument::<JsFunction>(0)?.root(&mut cx));
 
-	let mut rc = boxed.0.clone();
+	let rc = boxed.0.clone();
 	let channel = cx.channel();
 
 	// TODO when garbage collecting OperationController stop this worker
@@ -213,7 +217,7 @@ fn callback_cursor(mut cx: FunctionContext) -> JsResult<JsUndefined> {
 	let boxed : Handle<JsBox<CursorEventsHandle>> = this.get(&mut cx, "boxed")?;
 	let callback = Arc::new(cx.argument::<JsFunction>(0)?.root(&mut cx));
 
-	let mut rc = boxed.0.clone();
+	let rc = boxed.0.clone();
 	let channel = cx.channel();
 
 	// TODO when garbage collecting OperationController stop this worker

proto/buffer.proto

@@ -1,26 +1,16 @@
 syntax = "proto3";
-package buffer;
+
+package codemp.buffer;
 
 service Buffer {
 	rpc Attach (BufferPayload)    returns (stream RawOp);
-	rpc Edit   (OperationRequest) returns (BufferResponse);
+	rpc Edit   (OperationRequest) returns (BufferEditResponse);
-	rpc Create (BufferPayload)    returns (BufferResponse);
+	rpc Create (BufferPayload)    returns (BufferCreateResponse);
 	rpc Sync   (BufferPayload)    returns (BufferResponse);
-	rpc Moved  (Cursor)           returns (BufferResponse);
-	rpc Listen (BufferPayload)    returns (stream Cursor);
 }
 
-message Position {
+message BufferCreateResponse {}
-	int32 row = 1;
+message BufferEditResponse {}
-	int32 col = 2;
-}
-
-message Cursor {
-	string user = 1;
-	string buffer = 2;
-	Position start = 3;
-	Position end = 4;
-}
 
 message RawOp {
 	string opseq = 1;
@@ -41,6 +31,5 @@ message BufferPayload {
 }
 
 message BufferResponse {
-	bool accepted = 1;
+	string content = 2;
-	optional string content = 2;
 }

proto/cursor.proto

@@ -0,0 +1,30 @@
+syntax = "proto3";
+
+package codemp.cursor;
+
+service Cursor {
+	rpc Moved  (CursorEvent)      returns (MovedResponse);
+	rpc Listen (UserIdentity)     returns (stream CursorEvent);
+}
+
+message MovedResponse {}
+
+message RowCol {
+	int32 row = 1;
+	int32 col = 2;
+}
+
+message CursorPosition {
+	string buffer = 1;
+	RowCol start = 2;
+	RowCol end = 3;
+}
+
+message CursorEvent {
+	string user = 1;
+	CursorPosition position = 2;
+}
+
+message UserIdentity {
+	string id = 1;
+}

server/src/buffer/service.rs

@@ -1,17 +1,16 @@
 use std::{pin::Pin, sync::{Arc, RwLock}, collections::HashMap};
 
-use tokio::sync::{mpsc, broadcast, oneshot};
+use tokio::sync::{mpsc, oneshot};
 use tonic::{Request, Response, Status};
 
 use tokio_stream::{Stream, wrappers::ReceiverStream}; // TODO example used this?
 
-use codemp::proto::{buffer_server::{Buffer, BufferServer}, RawOp, BufferPayload, BufferResponse, OperationRequest, Cursor};
+use codemp::proto::{buffer_server::Buffer, RawOp, BufferPayload, BufferResponse, OperationRequest, BufferEditResponse, BufferCreateResponse};
 use tracing::info;
 
 use super::actor::{BufferHandle, BufferStore};
 
 type OperationStream = Pin<Box<dyn Stream<Item = Result<RawOp, Status>> + Send>>;
-type CursorStream    = Pin<Box<dyn Stream<Item = Result<Cursor, Status>> + Send>>;
 
 struct BufferMap {
 	store: HashMap<String, BufferHandle>,
@@ -34,15 +33,12 @@ impl BufferStore<String> for BufferMap {
 
 pub struct BufferService {
 	map: Arc<RwLock<BufferMap>>,
-	cursor: broadcast::Sender<Cursor>,
 }
 
-impl BufferService {
+impl Default for BufferService {
-	#[allow(unused)]
+	fn default() -> BufferService {
-	fn get_buffer(&self, path: &String) -> Result<BufferHandle, Status> {
+		BufferService {
-		match self.map.read().unwrap().get(path) {
+			map: Arc::new(RwLock::new(HashMap::new().into())),
-			Some(buf) => Ok(buf.clone()),
-			None => Err(Status::not_found("no buffer for given path")),
 		}
 	}
 }
@@ -50,7 +46,6 @@ impl BufferService {
 #[tonic::async_trait]
 impl Buffer for BufferService {
 	type AttachStream = OperationStream;
-	type ListenStream = CursorStream;
 
 	async fn attach(&self, req: Request<BufferPayload>) -> Result<Response<OperationStream>, Status> {
 		let request = req.into_inner();
@@ -73,29 +68,7 @@ impl Buffer for BufferService {
 		}
 	}
 
-	async fn listen(&self, req: Request<BufferPayload>) -> Result<Response<CursorStream>, Status> {
+	async fn edit(&self, req:Request<OperationRequest>) -> Result<Response<BufferEditResponse>, Status> {
-		let mut sub = self.cursor.subscribe();
-		let myself = req.into_inner().user;
-		let (tx, rx) = mpsc::channel(128);
-		tokio::spawn(async move {
-			while let Ok(v) = sub.recv().await {
-				if v.user == myself { continue }
-				tx.send(Ok(v)).await.unwrap(); // TODO unnecessary channel?
-			}
-		});
-		let output_stream = ReceiverStream::new(rx);
-		info!("registered new subscriber to cursor updates");
-		Ok(Response::new(Box::pin(output_stream)))
-	}
-
-	async fn moved(&self, req:Request<Cursor>) -> Result<Response<BufferResponse>, Status> {
-		match self.cursor.send(req.into_inner()) {
-			Ok(_) => Ok(Response::new(BufferResponse { accepted: true, content: None})),
-			Err(e) => Err(Status::internal(format!("could not broadcast cursor update: {}", e))),
-		}
-	}
-
-	async fn edit(&self, req:Request<OperationRequest>) -> Result<Response<BufferResponse>, Status> {
 		let request = req.into_inner();
 		let tx = match self.map.read().unwrap().get(&request.path) {
 			Some(handle) => {
@@ -110,19 +83,20 @@ impl Buffer for BufferService {
 		let (ack, status) = oneshot::channel();
 		match tx.send((ack, request)).await {
 			Err(e) => Err(Status::internal(format!("error sending edit to buffer actor: {}", e))),
-			Ok(()) => Ok(Response::new(BufferResponse {
+			Ok(()) => {
-				accepted: status.await.unwrap_or(false),
+				match status.await {
-				content: None 
+					Ok(_accepted) => Ok(Response::new(BufferEditResponse { })),
-			}))
+					Err(e) => Err(Status::internal(format!("error receiving edit result: {}", e))),
+				}
+			}
 		}
 	}
 	
-	async fn create(&self, req:Request<BufferPayload>) -> Result<Response<BufferResponse>, Status> {
+	async fn create(&self, req:Request<BufferPayload>) -> Result<Response<BufferCreateResponse>, Status> {
 		let request = req.into_inner();
 		let _handle = self.map.write().unwrap().handle(request.path, request.content);
 		info!("created new buffer");
-		let answ = BufferResponse { accepted: true, content: None };
+		Ok(Response::new(BufferCreateResponse { }))
-		Ok(Response::new(answ))
 	}
 
 	async fn sync(&self, req: Request<BufferPayload>) -> Result<Response<BufferResponse>, Status> {
@@ -131,23 +105,9 @@ impl Buffer for BufferService {
 			None => Err(Status::not_found("requested buffer does not exist")),
 			Some(buf) => {
 				info!("synching buffer");
-				let answ = BufferResponse { accepted: true, content: Some(buf.content.borrow().clone()) };
+				let answ = BufferResponse { content: buf.content.borrow().clone() };
 				Ok(Response::new(answ))
 			}
 		}
 	}
 }
-
-impl BufferService {
-	pub fn new() -> BufferService {
-		let (cur_tx, _cur_rx) = broadcast::channel(64); // TODO hardcoded capacity
-		BufferService {
-			map: Arc::new(RwLock::new(HashMap::new().into())),
-			cursor: cur_tx,
-		}
-	}
-
-	pub fn server(self) -> BufferServer<BufferService> {
-		BufferServer::new(self)
-	}
-}

server/src/cursor/mod.rs

@@ -0,0 +1 @@
+pub mod service;

server/src/cursor/service.rs

@@ -0,0 +1,52 @@
+use std::pin::Pin;
+
+use tokio::sync::{mpsc, broadcast};
+use tonic::{Request, Response, Status};
+
+use tokio_stream::{Stream, wrappers::ReceiverStream}; // TODO example used this?
+
+use codemp::proto::{cursor_server::Cursor, UserIdentity, CursorPosition, MovedResponse};
+use tracing::info;
+
+type CursorStream = Pin<Box<dyn Stream<Item = Result<CursorPosition, Status>> + Send>>;
+
+pub struct CursorService {
+	cursor: broadcast::Sender<CursorPosition>,
+}
+
+#[tonic::async_trait]
+impl Cursor for CursorService {
+	type ListenStream = CursorStream;
+
+	async fn listen(&self, req: Request<UserIdentity>) -> Result<Response<CursorStream>, Status> {
+		let mut sub = self.cursor.subscribe();
+		let myself = req.into_inner().id;
+		let (tx, rx) = mpsc::channel(128);
+		tokio::spawn(async move {
+			while let Ok(v) = sub.recv().await {
+				if v.user == myself { continue }
+				tx.send(Ok(v)).await.unwrap(); // TODO unnecessary channel?
+			}
+		});
+		let output_stream = ReceiverStream::new(rx);
+		info!("registered new subscriber to cursor updates");
+		Ok(Response::new(Box::pin(output_stream)))
+	}
+
+	async fn moved(&self, req:Request<CursorPosition>) -> Result<Response<MovedResponse>, Status> {
+		match self.cursor.send(req.into_inner()) {
+			Ok(_) => Ok(Response::new(MovedResponse { })),
+			Err(e) => Err(Status::internal(format!("could not broadcast cursor update: {}", e))),
+		}
+	}
+}
+
+impl Default for CursorService {
+	fn default() -> Self {
+		let (cur_tx, _cur_rx) = broadcast::channel(64); // TODO hardcoded capacity
+		// TODO don't drop receiver because sending event when there are no receivers throws an error
+		CursorService {
+			cursor: cur_tx,
+		}
+	}
+}

server/src/main.rs

@@ -5,12 +5,16 @@
 //!
 
 use clap::Parser;
+use codemp::proto::buffer_server::BufferServer;
+use codemp::proto::cursor_server::CursorServer;
 use tracing::info;
 use tonic::transport::Server;
 
 mod buffer;
+mod cursor;
 
 use crate::buffer::service::BufferService;
+use crate::cursor::service::CursorService;
 
 #[derive(Parser, Debug)]
 struct CliArgs {
@@ -37,7 +41,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 	info!("binding on {}", args.host);
 
 	Server::builder()
-		.add_service(BufferService::new().server())
+		.add_service(BufferServer::new(BufferService::default()))
+		.add_service(CursorServer::new(CursorService::default()))
 		.serve(args.host.parse()?)
 		.await?;
 

src/buffer/controller.rs

@@ -0,0 +1,41 @@
+use operational_transform::OperationSeq;
+use tokio::sync::{watch, mpsc, broadcast, Mutex};
+use tonic::async_trait;
+
+use crate::{Controller, CodempError};
+use crate::buffer::factory::{leading_noop, tailing_noop, OperationFactory};
+
+use super::TextChange;
+
+pub struct BufferController {
+	content: watch::Receiver<String>,
+	operations: mpsc::Sender<OperationSeq>,
+	stream: Mutex<broadcast::Receiver<OperationSeq>>,
+}
+
+#[async_trait]
+impl OperationFactory for BufferController {
+	fn content(&self) -> String {
+		self.content.borrow().clone()
+	}
+}
+
+#[async_trait]
+impl Controller<TextChange> for BufferController {
+	type Input = OperationSeq;
+
+	async fn recv(&self) -> Result<TextChange, CodempError> {
+		let op = self.stream.lock().await.recv().await?;
+		let after = self.content.borrow().clone();
+		let skip = leading_noop(op.ops()) as usize; 
+		let before_len = op.base_len();
+		let tail = tailing_noop(op.ops()) as usize;
+		let span = skip..before_len-tail;
+		let content = after[skip..after.len()-tail].to_string();
+		Ok(TextChange { span, content })
+	}
+
+	async fn send(&self, op: OperationSeq) -> Result<(), CodempError> {
+		Ok(self.operations.send(op).await?)
+	}
+}

src/buffer/factory.rs

@@ -1,6 +1,25 @@
-use operational_transform::OperationSeq;
+use std::ops::Range;
+
+use operational_transform::{OperationSeq, Operation};
 use similar::{TextDiff, ChangeTag};
 
+pub const fn leading_noop(seq: &[Operation]) -> u64 { count_noop(seq.first()) }
+pub const fn tailing_noop(seq: &[Operation]) -> u64 { count_noop(seq.last())  }
+
+const fn count_noop(op: Option<&Operation>) -> u64 {
+	match op {
+		None => 0,
+		Some(Operation::Retain(n)) => *n,
+		Some(_) => 0,
+	}
+}
+
+pub fn op_effective_range(op: &OperationSeq) -> Range<u64> {
+	let first = leading_noop(op.ops());
+	let last = op.base_len() as u64 - tailing_noop(op.ops());
+	first..last
+}
+
 pub trait OperationFactory {
 	fn content(&self) -> String;
 

src/buffer/mod.rs

@@ -0,0 +1,11 @@
+use std::ops::Range;
+
+pub(crate) mod worker;
+pub mod controller;
+pub mod factory;
+
+
+pub struct TextChange {
+	pub span: Range<usize>,
+	pub content: String,
+}

src/buffer/worker.rs

@@ -0,0 +1,114 @@
+use std::{sync::Arc, collections::VecDeque};
+
+use operational_transform::OperationSeq;
+use tokio::sync::{watch, mpsc, broadcast, Mutex};
+use tonic::transport::Channel;
+use tonic::{async_trait, Streaming};
+
+use crate::proto::{OperationRequest, RawOp};
+use crate::proto::buffer_client::BufferClient;
+use crate::ControllerWorker;
+
+use super::TextChange;
+use super::controller::BufferController;
+
+
+pub(crate) struct BufferControllerWorker {
+	uid: String,
+	pub(crate) content: watch::Sender<String>,
+	pub(crate) operations: mpsc::Receiver<OperationSeq>,
+	pub(crate) stream: Arc<broadcast::Sender<OperationSeq>>,
+	pub(crate) queue: VecDeque<OperationSeq>,
+	receiver: watch::Receiver<String>,
+	sender: mpsc::Sender<OperationSeq>,
+	buffer: String,
+	path: String,
+}
+
+impl BufferControllerWorker {
+	pub fn new(uid: String, buffer: &str, path: &str) -> Self {
+		let (txt_tx, txt_rx) = watch::channel(buffer.to_string());
+		let (op_tx, op_rx) = mpsc::channel(64);
+		let (s_tx, _s_rx) = broadcast::channel(64);
+		BufferControllerWorker {
+			uid,
+			content: txt_tx,
+			operations: op_rx,
+			stream: Arc::new(s_tx),
+			receiver: txt_rx,
+			sender: op_tx,
+			queue: VecDeque::new(),
+			buffer: buffer.to_string(),
+			path: path.to_string(),
+		}
+	}
+}
+
+#[async_trait]
+impl ControllerWorker<TextChange> for BufferControllerWorker {
+	type Controller = BufferController;
+	type Tx = BufferClient<Channel>;
+	type Rx = Streaming<RawOp>;
+
+	fn subscribe(&self) -> BufferController {
+		BufferController {
+			content: self.receiver.clone(),
+			operations: self.sender.clone(),
+			stream: Mutex::new(self.stream.subscribe()),
+		}
+	}
+
+	async fn work(mut self, mut tx: Self::Tx, mut rx: Self::Rx) {
+		loop {
+			let op = tokio::select! {
+				Some(operation) = recv_opseq(&mut rx) => {
+					let mut out = operation;
+					for op in self.queue.iter_mut() {
+						(*op, out) = op.transform(&out).unwrap();
+					}
+					self.stream.send(out.clone()).unwrap();
+					out
+				},
+				Some(op) = self.operations.recv() => {
+					self.queue.push_back(op.clone());
+					op
+				},
+				else => break
+			};
+			self.buffer = op.apply(&self.buffer).unwrap();
+			self.content.send(self.buffer.clone()).unwrap();
+
+			while let Some(op) = self.queue.get(0) {
+				if !send_opseq(&mut tx, self.uid.clone(), self.path.clone(), op.clone()).await { break }
+				self.queue.pop_front();
+			}
+		}
+	}
+}
+
+async fn send_opseq(tx: &mut BufferClient<Channel>, uid: String, path: String, op: OperationSeq) -> bool {
+	let req = OperationRequest {
+		hash: "".into(),
+		opseq: serde_json::to_string(&op).unwrap(),
+		path,
+		user: uid,
+	};
+	match tx.edit(req).await {
+		Ok(_) => true,
+		Err(e) => {
+			tracing::error!("error sending edit: {}", e);
+			false
+		}
+	}
+}
+
+async fn recv_opseq(rx: &mut Streaming<RawOp>) -> Option<OperationSeq> {
+	match rx.message().await {
+		Ok(Some(op)) => Some(serde_json::from_str(&op.opseq).unwrap()),
+		Ok(None) => None,
+		Err(e) => {
+			tracing::error!("could not receive edit from server: {}", e);
+			None
+		}
+	}
+}

src/client.rs

@@ -1,143 +1,117 @@
-use operational_transform::OperationSeq;
+use std::{sync::Arc, collections::BTreeMap};
-use tonic::{transport::Channel, Status, Streaming, async_trait};
+
-use uuid::Uuid;
+use tonic::transport::Channel;
 
 use crate::{
-	controller::{ControllerWorker,
+	cursor::{worker::CursorControllerWorker, controller::CursorController},
-		cursor::{CursorControllerHandle, CursorControllerWorker, CursorEditor},
+	proto::{
-		buffer::{OperationControllerHandle, OperationControllerEditor, OperationControllerWorker}
+		buffer_client::BufferClient, cursor_client::CursorClient, UserIdentity, BufferPayload,
 	},
-	proto::{buffer_client::BufferClient, BufferPayload, RawOp, OperationRequest, Cursor},
+	CodempError, ControllerWorker, buffer::{controller::BufferController, worker::BufferControllerWorker},
 };
 
-#[derive(Clone)]
+
 pub struct CodempClient {
 	id: String,
-	client: BufferClient<Channel>,
+	client: ServiceClients,
+	workspace: Option<Workspace>,
 }
 
-impl From::<BufferClient<Channel>> for CodempClient {
+struct ServiceClients {
-	fn from(value: BufferClient<Channel>) -> Self {
+	buffer: BufferClient<Channel>,
-		CodempClient { id: Uuid::new_v4().to_string(), client: value }
+	cursor: CursorClient<Channel>,
-	}
 }
 
+struct Workspace {
+	cursor: Arc<CursorController>,
+	buffers: BTreeMap<String, Arc<BufferController>>,
+}
+
+
 impl CodempClient {
-	pub async fn new(dest: &str) -> Result<Self, tonic::transport::Error> {
+	pub async fn new(dst: &str) -> Result<Self, tonic::transport::Error> {
-		Ok(BufferClient::connect(dest.to_string()).await?.into())
+		let buffer = BufferClient::connect(dst.to_string()).await?;
+		let cursor = CursorClient::connect(dst.to_string()).await?;
+		let id = uuid::Uuid::new_v4().to_string();
+		
+		Ok(CodempClient { id, client: ServiceClients { buffer, cursor}, workspace: None })
 	}
 
-	pub fn id(&self) -> &str { &self.id	}
+	pub fn get_cursor(&self) -> Option<Arc<CursorController>> {
-
+		Some(self.workspace?.cursor.clone())
-	pub async fn create(&mut self, path: String, content: Option<String>) -> Result<bool, Status> {
-		let req = BufferPayload {
-			path, content,
-			user: self.id.clone(),
-		};
-
-		let res = self.client.create(req).await?;
-
-		Ok(res.into_inner().accepted)
 	}
 
-	pub async fn listen(&mut self) -> Result<CursorControllerHandle, Status> {
+	pub fn get_buffer(&self, path: &str) -> Option<Arc<BufferController>> {
-		let req = BufferPayload {
+		self.workspace?.buffers.get(path).cloned()
-			path: "".into(),
+	}
-			content: None,
-			user: self.id.clone(),
-		};
 
-		let stream = self.client.listen(req).await?.into_inner();
+	pub async fn join(&mut self, _session: &str) -> Result<Arc<CursorController>, CodempError> {
+		// TODO there is no real workspace handling in codemp server so it behaves like one big global
+		//  session. I'm still creating this to start laying out the proper use flow
+		let stream = self.client.cursor.listen(UserIdentity { id: "".into() }).await?.into_inner();
 
-		let controller = CursorControllerWorker::new(self.id().to_string(), (self.clone(), stream));
+		let controller = CursorControllerWorker::new(self.id.clone());
-		let handle = controller.subscribe();
+		let client = self.client.cursor.clone();
+
+		let handle = Arc::new(controller.subscribe());
 
 		tokio::spawn(async move {
 			tracing::debug!("cursor worker started");
-			controller.work().await;
+			controller.work(client, stream).await;
 			tracing::debug!("cursor worker stopped");
 		});
 
+		self.workspace = Some(
+			Workspace {
+				cursor: handle.clone(),
+				buffers: BTreeMap::new()
+			}
+		);
+
 		Ok(handle)
 	}
 
-	pub async fn attach(&mut self, path: String) -> Result<OperationControllerHandle, Status> {
+	pub async fn create(&mut self, path: &str, content: Option<&str>) -> Result<(), CodempError> {
-		let req = BufferPayload {
+		if let Some(workspace) = &self.workspace {
-			path: path.clone(),
+			self.client.buffer
-			content: None,
+				.create(BufferPayload {
-			user: self.id.clone(),
+					user: self.id.clone(),
-		};
+					path: path.to_string(),
+					content: content.map(|x| x.to_string()),
+				}).await?;
 
-		let content = self.client.sync(req.clone())
+			Ok(())
-			.await?
+		} else {
-			.into_inner()
+			Err(CodempError::InvalidState { msg: "join a workspace first".into() })
-			.content
-			.unwrap_or("".into());
-
-		let stream = self.client.attach(req).await?.into_inner();
-
-		let controller = OperationControllerWorker::new((self.clone(), stream), content, path);
-		let factory = controller.subscribe();
-
-		tokio::spawn(async move {
-			tracing::debug!("buffer worker started");
-			controller.work().await;
-			tracing::debug!("buffer worker stopped");
-		});
-
-		Ok(factory)
-	}
-}
-
-#[async_trait]
-impl OperationControllerEditor for (CodempClient, Streaming<RawOp>) {
-	async fn edit(&mut self, path: String, op: OperationSeq) -> bool {
-		let req = OperationRequest {
-			hash: "".into(),
-			opseq: serde_json::to_string(&op).unwrap(),
-			path,
-			user: self.0.id().to_string(),
-		};
-		match self.0.client.edit(req).await {
-			Ok(res) => res.into_inner().accepted,
-			Err(e) => {
-				tracing::error!("error sending edit: {}", e);
-				false
-			}
 		}
 	}
 
-	async fn recv(&mut self) -> Option<OperationSeq> {
+	pub async fn attach(&mut self, path: &str, content: Option<&str>) -> Result<Arc<BufferController>, CodempError> {
-		match self.1.message().await {
+		if let Some(workspace) = &mut self.workspace {
-			Ok(Some(op)) => Some(serde_json::from_str(&op.opseq).unwrap()),
+			let mut client = self.client.buffer.clone();
-			Ok(None) => None,
+			let req = BufferPayload {
-			Err(e) => {
+				path: path.to_string(), user: self.id.clone(), content: None
-				tracing::error!("could not receive edit from server: {}", e);
+			};
-				None
+
-			}
+			let content = client.sync(req.clone()).await?.into_inner().content;
-		}
+
-	}
+			let stream = client.attach(req).await?.into_inner();
-}
+
-
+			let controller = BufferControllerWorker::new(self.id.clone(), &content, path);
-#[async_trait]
+			let handler = Arc::new(controller.subscribe());
-impl CursorEditor for (CodempClient, Streaming<Cursor>) {
+
-	async fn moved(&mut self, cursor: Cursor) -> bool {
+			let _path = path.to_string();
-		match self.0.client.moved(cursor).await {
+			tokio::spawn(async move {
-			Ok(res) => res.into_inner().accepted,
+				tracing::debug!("buffer[{}] worker started", _path);
-			Err(e) => {
+				controller.work(client, stream).await;
-				tracing::error!("could not send cursor movement: {}", e);
+				tracing::debug!("buffer[{}] worker stopped", _path);
-				false
+			});
-			}
+
-		}
+			workspace.buffers.insert(path.to_string(), handler.clone());
-	}
+
-
+			Ok(handler)
-	async fn recv(&mut self) -> Option<Cursor> {
+		} else {
-		match self.1.message().await {
+			Err(CodempError::InvalidState { msg: "join a workspace first".into() })
-			Ok(cursor) => cursor,
-			Err(e) => {
-				tracing::error!("could not receive cursor update: {}", e);
-				None
-			}
 		}
 	}
 }

src/controller/buffer.rs

@@ -1,139 +0,0 @@
-use std::{sync::Arc, collections::VecDeque, ops::Range};
-
-use operational_transform::OperationSeq;
-use tokio::sync::{watch, mpsc, broadcast};
-use tonic::async_trait;
-
-use super::{leading_noop, tailing_noop, ControllerWorker};
-use crate::errors::IgnorableError;
-use crate::factory::OperationFactory;
-
-pub struct TextChange {
-	pub span: Range<usize>,
-	pub content: String,
-}
-
-#[async_trait]
-pub trait OperationControllerSubscriber {
-	async fn poll(&mut self) -> Option<TextChange>;
-	async fn apply(&self, op: OperationSeq);
-}
-
-pub struct OperationControllerHandle {
-	content: watch::Receiver<String>,
-	operations: mpsc::Sender<OperationSeq>,
-	original: Arc<broadcast::Sender<OperationSeq>>,
-	stream: broadcast::Receiver<OperationSeq>,
-}
-
-impl Clone for OperationControllerHandle {
-	fn clone(&self) -> Self {
-		OperationControllerHandle {
-			content: self.content.clone(),
-			operations: self.operations.clone(),
-			original: self.original.clone(),
-			stream: self.original.subscribe(),
-		}
-	}
-}
-
-#[async_trait]
-impl OperationFactory for OperationControllerHandle {
-	fn content(&self) -> String {
-		self.content.borrow().clone()
-	}
-}
-
-#[async_trait]
-impl OperationControllerSubscriber for OperationControllerHandle {
-	async fn poll(&mut self) -> Option<TextChange> {
-		let op = self.stream.recv().await.ok()?;
-		let after = self.content.borrow().clone();
-		let skip = leading_noop(op.ops()) as usize; 
-		let before_len = op.base_len();
-		let tail = tailing_noop(op.ops()) as usize;
-		let span = skip..before_len-tail;
-		let content = after[skip..after.len()-tail].to_string();
-		Some(TextChange { span, content })
-	}
-
-	async fn apply(&self, op: OperationSeq) {
-		self.operations.send(op).await
-			.unwrap_or_warn("could not apply+send operation")
-	}
-}
-
-#[async_trait]
-pub(crate) trait OperationControllerEditor {
-	async fn edit(&mut self, path: String, op: OperationSeq) -> bool;
-	async fn recv(&mut self) -> Option<OperationSeq>;
-}
-
-pub(crate) struct OperationControllerWorker<C : OperationControllerEditor> {
-	pub(crate) content: watch::Sender<String>,
-	pub(crate) operations: mpsc::Receiver<OperationSeq>,
-	pub(crate) stream: Arc<broadcast::Sender<OperationSeq>>,
-	pub(crate) queue: VecDeque<OperationSeq>,
-	receiver: watch::Receiver<String>,
-	sender: mpsc::Sender<OperationSeq>,
-	client: C,
-	buffer: String,
-	path: String,
-}
-
-#[async_trait]
-impl<C : OperationControllerEditor + Send> ControllerWorker<OperationControllerHandle> for OperationControllerWorker<C> {
-	fn subscribe(&self) -> OperationControllerHandle {
-		OperationControllerHandle {
-			content: self.receiver.clone(),
-			operations: self.sender.clone(),
-			original: self.stream.clone(),
-			stream: self.stream.subscribe(),
-		}
-	}
-
-	async fn work(mut self) {
-		loop {
-			let op = tokio::select! {
-				Some(operation) = self.client.recv() => {
-					let mut out = operation;
-					for op in self.queue.iter_mut() {
-						(*op, out) = op.transform(&out).unwrap();
-					}
-					self.stream.send(out.clone()).unwrap();
-					out
-				},
-				Some(op) = self.operations.recv() => {
-					self.queue.push_back(op.clone());
-					op
-				},
-				else => break
-			};
-			self.buffer = op.apply(&self.buffer).unwrap();
-			self.content.send(self.buffer.clone()).unwrap();
-
-			while let Some(op) = self.queue.get(0) {
-				if !self.client.edit(self.path.clone(), op.clone()).await { break }
-				self.queue.pop_front();
-			}
-		}
-	}
-
-}
-
-impl<C : OperationControllerEditor> OperationControllerWorker<C> {
-	pub fn new(client: C, buffer: String, path: String) -> Self {
-		let (txt_tx, txt_rx) = watch::channel(buffer.clone());
-		let (op_tx, op_rx) = mpsc::channel(64);
-		let (s_tx, _s_rx) = broadcast::channel(64);
-		OperationControllerWorker {
-			content: txt_tx,
-			operations: op_rx,
-			stream: Arc::new(s_tx),
-			receiver: txt_rx,
-			sender: op_tx,
-			queue: VecDeque::new(),
-			client, buffer, path
-		}
-	}
-}

src/controller/cursor.rs

@@ -1,104 +0,0 @@
-use std::sync::Arc;
-
-use tokio::sync::{mpsc, broadcast};
-use tonic::async_trait;
-
-use crate::{proto::{Position, Cursor}, errors::IgnorableError, controller::ControllerWorker};
-
-#[async_trait]
-pub trait CursorSubscriber {
-	async fn send(&self, path: &str, start: Position, end: Position);
-	async fn poll(&mut self) -> Option<Cursor>;
-}
-
-pub struct CursorControllerHandle {
-	uid: String,
-	op: mpsc::Sender<Cursor>,
-	stream: broadcast::Receiver<Cursor>,
-	original: Arc<broadcast::Sender<Cursor>>,
-}
-
-impl Clone for CursorControllerHandle {
-	fn clone(&self) -> Self {
-		Self {
-			uid: self.uid.clone(),
-			op: self.op.clone(),
-			stream: self.original.subscribe(),
-			original: self.original.clone()
-		}
-	}
-}
-
-#[async_trait]
-impl CursorSubscriber for CursorControllerHandle {
-	async fn send(&self, path: &str, start: Position, end: Position) {
-		self.op.send(Cursor {
-			user: self.uid.clone(),
-			buffer: path.to_string(),
-			start: Some(start),
-			end: Some(end),
-		}).await.unwrap_or_warn("could not send cursor op")
-	}
-
-	async fn poll(&mut self) -> Option<Cursor> {
-		match self.stream.recv().await {
-			Ok(x) => Some(x),
-			Err(e) => {
-				tracing::warn!("could not poll for cursor: {}", e);
-				None
-			}
-		}
-	}
-}
-
-#[async_trait]
-pub(crate) trait CursorEditor {
-	async fn moved(&mut self, cursor: Cursor) -> bool;
-	async fn recv(&mut self) -> Option<Cursor>;
-}
-
-pub(crate) struct CursorControllerWorker<C : CursorEditor> {
-	uid: String,
-	producer: mpsc::Sender<Cursor>,
-	op: mpsc::Receiver<Cursor>,
-	channel: Arc<broadcast::Sender<Cursor>>,
-	client: C,
-}
-
-impl<C : CursorEditor> CursorControllerWorker<C> {
-	pub(crate) fn new(uid: String, client: C) -> Self {
-		let (op_tx, op_rx) = mpsc::channel(64);
-		let (cur_tx, _cur_rx) = broadcast::channel(64);
-		CursorControllerWorker {
-			uid, client,
-			producer: op_tx,
-			op: op_rx,
-			channel: Arc::new(cur_tx),
-		}
-	}
-}
-
-#[async_trait]
-impl<C : CursorEditor + Send> ControllerWorker<CursorControllerHandle> for CursorControllerWorker<C> {
-	fn subscribe(&self) -> CursorControllerHandle {
-		CursorControllerHandle {
-			uid: self.uid.clone(),
-			op: self.producer.clone(),
-			stream: self.channel.subscribe(),
-			original: self.channel.clone(),
-		}
-	}
-
-	async fn work(mut self) {
-		loop {
-			tokio::select!{
-				Some(cur) = self.client.recv() => self.channel.send(cur).unwrap_or_warn("could not broadcast event"),
-				Some(op) = self.op.recv() => { self.client.moved(op).await; },
-				else => break,
-			}
-		}
-	}
-
-}
-
-

src/controller/mod.rs

@@ -1,30 +0,0 @@
-pub mod buffer;
-pub mod cursor;
-
-use std::ops::Range;
-
-use operational_transform::{Operation, OperationSeq};
-use tonic::async_trait;
-
-#[async_trait]
-pub trait ControllerWorker<T> {
-	fn subscribe(&self) -> T;
-	async fn work(self);
-}
-
-pub const fn leading_noop(seq: &[Operation]) -> u64 { count_noop(seq.first()) }
-pub const fn tailing_noop(seq: &[Operation]) -> u64 { count_noop(seq.last())  }
-
-const fn count_noop(op: Option<&Operation>) -> u64 {
-	match op {
-		None => 0,
-		Some(Operation::Retain(n)) => *n,
-		Some(_) => 0,
-	}
-}
-
-pub fn op_effective_range(op: &OperationSeq) -> Range<u64> {
-	let first = leading_noop(op.ops());
-	let last = op.base_len() as u64 - tailing_noop(op.ops());
-	first..last
-}

src/cursor.rs

@@ -1,23 +0,0 @@
-use crate::proto::{Position, Cursor};
-
-impl From::<Position> for (i32, i32) {
-	fn from(pos: Position) -> (i32, i32) {
-		(pos.row, pos.col)
-	}
-}
-
-impl From::<(i32, i32)> for Position {
-	fn from((row, col): (i32, i32)) -> Self {
-		Position { row, col }
-	}
-}
-
-impl Cursor {
-	pub fn start(&self) -> Position {
-		self.start.clone().unwrap_or((0, 0).into())
-	}
-
-	pub fn end(&self) -> Position {
-		self.end.clone().unwrap_or((0, 0).into())
-	}
-}

src/cursor/controller.rs

@@ -0,0 +1,51 @@
+use tokio::sync::{mpsc, broadcast::{self, error::RecvError}, Mutex};
+use tonic::async_trait;
+
+use crate::{proto::{CursorPosition, CursorEvent}, CodempError, Controller};
+
+pub struct CursorController {
+	uid: String,
+	op: mpsc::Sender<CursorEvent>,
+	stream: Mutex<broadcast::Receiver<CursorEvent>>,
+}
+
+#[async_trait]
+impl Controller<CursorEvent> for CursorController {
+	type Input = CursorPosition;
+
+	async fn send(&self, cursor: CursorPosition) -> Result<(), CodempError> {
+		Ok(self.op.send(CursorEvent {
+			user: self.uid.clone(),
+			position: Some(cursor),
+		}).await?)
+	}
+
+	// TODO is this cancelable? so it can be used in tokio::select!
+	// TODO is the result type overkill? should be an option?
+	async fn recv(&self) -> Result<CursorEvent, CodempError> {
+		let mut stream = self.stream.lock().await;
+		match stream.recv().await {
+			Ok(x) => Ok(x),
+			Err(RecvError::Closed) => Err(CodempError::Channel { send: false }),
+			Err(RecvError::Lagged(n)) => {
+				tracing::error!("cursor channel lagged behind, skipping {} events", n);
+				Ok(stream.recv().await.expect("could not receive after lagging"))
+			}
+		}
+	}
+
+	// fn try_poll(&self) -> Option<Option<CursorPosition>> {
+	// 	match self.stream.try_lock() {
+	// 		Err(_) => None,
+	// 		Ok(mut x) => match x.try_recv() {
+	// 			Ok(x) => Some(Some(x)),
+	// 			Err(TryRecvError::Empty) => None,
+	// 			Err(TryRecvError::Closed) => Some(None),
+	// 			Err(TryRecvError::Lagged(n)) => {
+	// 				tracing::error!("cursor channel lagged behind, skipping {} events", n);
+	// 				Some(Some(x.try_recv().expect("could not receive after lagging")))
+	// 			}
+	// 		}
+	// 	}
+	// }
+}

src/cursor/mod.rs

@@ -0,0 +1,26 @@
+pub(crate) mod worker;
+pub mod controller;
+
+use crate::proto::{RowCol, CursorPosition};
+
+impl From::<RowCol> for (i32, i32) {
+	fn from(pos: RowCol) -> (i32, i32) {
+		(pos.row, pos.col)
+	}
+}
+
+impl From::<(i32, i32)> for RowCol {
+	fn from((row, col): (i32, i32)) -> Self {
+		RowCol { row, col }
+	}
+}
+
+impl CursorPosition {
+	pub fn start(&self) -> RowCol {
+		self.start.clone().unwrap_or((0, 0).into())
+	}
+
+	pub fn end(&self) -> RowCol {
+		self.end.clone().unwrap_or((0, 0).into())
+	}
+}

src/cursor/worker.rs

@@ -0,0 +1,54 @@
+use std::sync::Arc;
+
+use tokio::sync::{mpsc, broadcast::{self}, Mutex};
+use tonic::{Streaming, transport::Channel, async_trait};
+
+use crate::{proto::{cursor_client::CursorClient, CursorEvent}, errors::IgnorableError, ControllerWorker};
+
+use super::controller::CursorController;
+
+pub(crate) struct CursorControllerWorker {
+	uid: String,
+	producer: mpsc::Sender<CursorEvent>,
+	op: mpsc::Receiver<CursorEvent>,
+	channel: Arc<broadcast::Sender<CursorEvent>>,
+}
+
+impl CursorControllerWorker {
+	pub(crate) fn new(uid: String) -> Self {
+		let (op_tx, op_rx) = mpsc::channel(64);
+		let (cur_tx, _cur_rx) = broadcast::channel(64);
+		Self {
+			uid,
+			producer: op_tx,
+			op: op_rx,
+			channel: Arc::new(cur_tx),
+		}
+	}
+}
+
+#[async_trait]
+impl ControllerWorker<CursorEvent> for CursorControllerWorker {
+	type Controller = CursorController;
+	type Tx = CursorClient<Channel>;
+	type Rx = Streaming<CursorEvent>;
+
+	fn subscribe(&self) -> CursorController {
+		CursorController {
+			uid: self.uid.clone(),
+			op: self.producer.clone(),
+			stream: Mutex::new(self.channel.subscribe()),
+		}
+	}
+
+	async fn work(mut self, mut tx: Self::Tx, mut rx: Self::Rx) {
+		loop {
+			tokio::select!{
+				Ok(Some(cur)) = rx.message() => self.channel.send(cur).unwrap_or_warn("could not broadcast event"),
+				Some(op) = self.op.recv() => { tx.moved(op).await.unwrap_or_warn("could not update cursor"); },
+				else => break,
+			}
+		}
+	}
+}
+

src/errors.rs

@@ -1,3 +1,7 @@
+use std::{error::Error, fmt::Display};
+
+use tokio::sync::{mpsc, broadcast};
+use tonic::{Status, Code};
 use tracing::warn;
 
 pub trait IgnorableError {
@@ -13,3 +17,61 @@ where E : std::fmt::Display {
 		}
 	}
 }
+
+// TODO split this into specific errors for various parts of the library
+#[derive(Debug)]
+pub enum CodempError {
+	Transport {
+		status: Code,
+		message: String,
+	},
+	Channel {
+		send: bool
+	},
+	InvalidState {
+		msg: String,
+	},
+
+	// TODO filler error, remove later
+	Filler {
+		message: String,
+	},
+}
+
+impl Error for CodempError {}
+
+impl Display for CodempError {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		match self {
+			Self::Transport { status, message } => write!(f, "Transport error: ({}) {}", status, message),
+			Self::Channel { send } => write!(f, "Channel error (send:{})", send),
+			_ => write!(f, "Unknown error"),
+		}
+	}
+}
+
+impl From<Status> for CodempError {
+	fn from(status: Status) -> Self {
+		CodempError::Transport { status: status.code(), message: status.message().to_string() }
+	}
+}
+
+impl From<tonic::transport::Error> for CodempError {
+	fn from(err: tonic::transport::Error) -> Self {
+		CodempError::Transport {
+			status: Code::Unknown, message: format!("underlying transport error: {:?}", err)
+		}
+	}
+}
+
+impl<T> From<mpsc::error::SendError<T>> for CodempError {
+	fn from(_value: mpsc::error::SendError<T>) -> Self {
+		CodempError::Channel { send: true }
+	}
+}
+
+impl From<broadcast::error::RecvError> for CodempError {
+	fn from(_value: broadcast::error::RecvError) -> Self {
+		CodempError::Channel { send: false }
+	}
+}

src/instance.rs

@@ -0,0 +1,81 @@
+use std::sync::Arc;
+
+use tokio::sync::Mutex;
+
+use crate::{
+	buffer::controller::BufferController,
+	errors::CodempError, client::CodempClient, cursor::controller::CursorController,
+};
+
+
+use tokio::runtime::Runtime;
+
+const CODEMP_DEFAULT_HOST : &str = "http://alemi.dev:50051";
+
+lazy_static::lazy_static! {
+	static ref RUNTIME  : Runtime  = Runtime::new().expect("could not create tokio runtime");
+	static ref INSTANCE : Instance = Instance::default();
+}
+
+pub struct Instance {
+	client: Mutex<Option<CodempClient>>,
+}
+
+impl Default for Instance {
+	fn default() -> Self {
+		Instance { client: Mutex::new(None) }
+	}
+}
+
+// TODO these methods repeat a lot of code but Mutex makes it hard to simplify
+
+impl Instance {
+	pub async fn connect(&self, addr: &str) -> Result<(), CodempError> {
+		*self.client.lock().await = Some(CodempClient::new(addr).await?);
+		Ok(())
+	}
+
+	pub async fn join(&self, session: &str) -> Result<(), CodempError> {
+		self.client
+			.lock()
+			.await
+			.as_mut()
+			.ok_or(CodempError::InvalidState { msg: "connect first".into() })?
+			.join(session)
+			.await?;
+
+		Ok(())
+	}
+
+	pub async fn create(&self, path: &str, content: Option<&str>) -> Result<(), CodempError> {
+		self.client
+			.lock()
+			.await
+			.as_mut()
+			.ok_or(CodempError::InvalidState { msg: "connect first".into() })?
+			.create(path, content)
+			.await?;
+
+		Ok(())
+	}
+
+	pub async fn get_cursor(&self) -> Result<Arc<CursorController>, CodempError> {
+		self.client
+			.lock()
+			.await
+			.as_mut()
+			.ok_or(CodempError::InvalidState { msg: "connect first".into() })?
+			.get_cursor()
+			.ok_or(CodempError::InvalidState { msg: "join a workspace first".into() })
+	}
+
+	pub async fn get_buffer(&self, path: &str) -> Result<Arc<BufferController>, CodempError> {
+		self.client
+			.lock()
+			.await
+			.as_mut()
+			.ok_or(CodempError::InvalidState { msg: "connect first".into() })?
+			.get_buffer(path)
+			.ok_or(CodempError::InvalidState { msg: "join a workspace or create requested buffer first".into() })
+	}
+}

src/lib.rs

@@ -1,12 +1,39 @@
-pub mod proto;
-pub mod client;
-pub mod workspace;
-pub mod controller;
 pub mod cursor;
 pub mod errors;
-pub mod factory;
+pub mod buffer;
+
+pub mod client;
+
+#[cfg(feature = "static")]
+pub mod instance;
 
 pub use tonic;
 pub use tokio;
 pub use operational_transform as ot;
 
+#[cfg(feature = "proto")]
+#[allow(non_snake_case)]
+pub mod proto {
+	tonic::include_proto!("codemp.buffer");
+	tonic::include_proto!("codemp.cursor");
+}
+
+pub use errors::CodempError;
+
+#[tonic::async_trait] // TODO move this somewhere?
+pub(crate) trait ControllerWorker<T> {
+	type Controller : Controller<T>;
+	type Tx;
+	type Rx;
+
+	fn subscribe(&self) -> Self::Controller;
+	async fn work(self, tx: Self::Tx, rx: Self::Rx);
+}
+
+#[tonic::async_trait]
+pub trait Controller<T> {
+	type Input;
+
+	async fn send(&self, x: Self::Input) -> Result<(), CodempError>;
+	async fn recv(&self) -> Result<T, CodempError>;
+}

src/proto.rs

@@ -1 +0,0 @@
-tonic::include_proto!("buffer");

src/workspace.rs

@@ -1,57 +0,0 @@
-use std::{collections::BTreeMap, ops::Range};
-
-use tokio::sync::RwLock;
-use tonic::Status;
-
-use crate::{
-	client::CodempClient, factory::OperationFactory,
-	controller::{buffer::{OperationControllerHandle, OperationControllerSubscriber},
-	cursor::{CursorControllerHandle, CursorSubscriber}}, proto::Cursor,
-};
-
-pub struct Workspace {
-	client: CodempClient,
-	buffers: RwLock<BTreeMap<String, OperationControllerHandle>>,
-	cursor: RwLock<CursorControllerHandle>,
-}
-
-impl Workspace {
-	pub async fn new(mut client: CodempClient) -> Result<Self, Status> {
-		Ok(
-			Workspace {
-				cursor: RwLock::new(client.listen().await?),
-				client,
-				buffers: RwLock::new(BTreeMap::new()),
-			}
-		)
-	}
-
-	pub async fn create(&self, path: &str, content: Option<String>) -> Result<bool, Status> {
-		self.client.clone().create(path.into(), content).await
-	}
-
-	pub async fn attach(&self, path: String) -> Result<(), Status> {
-		self.buffers.write().await.insert(
-			path.clone(),
-			self.client.clone().attach(path).await?
-		);
-		Ok(())
-	}
-
-	pub async fn diff(&self, path: &str, span: Range<usize>, text: &str) {
-		if let Some(controller) = self.buffers.read().await.get(path) {
-			if let Some(op) = controller.delta(span.start, text, span.end) {
-				controller.apply(op).await
-			}
-		}
-	}
-
-	pub async fn send(&self, path: &str, start: (i32, i32), end: (i32, i32)) {
-		self.cursor.read().await.send(path, start.into(), end.into()).await
-	}
-
-	pub async fn recv(&self) -> Option<Cursor> {
-		self.cursor.write().await.poll().await
-
-	}
-}