chore: made OperationFactory async and mutexless

src/lib/client.rs

@@ -1,23 +1,21 @@
 /// TODO better name for this file
 
-use std::sync::{Arc, Mutex};
+use std::sync::Arc;
 use tracing::{error, warn};
 use uuid::Uuid;
 
 use crate::{
-	opfactory::OperationFactory,
+	opfactory::AsyncFactory,
 	proto::{buffer_client::BufferClient, BufferPayload, OperationRequest, RawOp},
 	tonic::{transport::Channel, Status, Streaming},
 };
 
-type FactoryHandle = Arc<Mutex<OperationFactory>>;
-
 impl From::<BufferClient<Channel>> for CodempClient {
 	fn from(x: BufferClient<Channel>) -> CodempClient {
 		CodempClient {
 			id: Uuid::new_v4(),
 			client:x,
-			factory: Arc::new(Mutex::new(OperationFactory::new(None)))
+			factory: Arc::new(AsyncFactory::new(None)),
 		}
 	}
 }
@@ -26,7 +24,7 @@ impl From::<BufferClient<Channel>> for CodempClient {
 pub struct CodempClient {
 	id: Uuid,
 	client: BufferClient<Channel>,
-	factory: FactoryHandle, // TODO less jank solution than Arc<Mutex>
+	factory: Arc<AsyncFactory>,
 }
 
 impl CodempClient {
@@ -46,8 +44,7 @@ impl CodempClient {
 	}
 
 	pub async fn insert(&mut self, path: String, txt: String, pos: u64) -> Result<bool, Status> {
-		let res = { self.factory.lock().unwrap().insert(&txt, pos) };
-		match res {
+		match self.factory.insert(txt, pos).await {
 			Ok(op) => {
 				Ok(
 					self.client.edit(
@@ -68,8 +65,7 @@ impl CodempClient {
 	}
 
 	pub async fn delete(&mut self, path: String, pos: u64, count: u64) -> Result<bool, Status> {
-		let res = { self.factory.lock().unwrap().delete(pos, count) };
-		match res {
+		match self.factory.delete(pos, count).await {
 			Ok(op) => {
 				Ok(
 					self.client.edit(
@@ -106,31 +102,32 @@ impl CodempClient {
 		Ok(())
 	}
 
-	async fn worker<F : Fn(String) -> ()>(mut stream: Streaming<RawOp>, factory: FactoryHandle, callback: F) {
+	pub async fn sync(&mut self, path: String) -> Result<String, Status> {
+		let res = self.client.sync(
+			BufferPayload {
+				path, content: None, user: self.id.to_string(),
+			}
+		).await?;
+		Ok(res.into_inner().content.unwrap_or("".into()))
+	}
+
+	async fn worker<F : Fn(String) -> ()>(mut stream: Streaming<RawOp>, factory: Arc<AsyncFactory>, callback: F) {
 		loop {
 			match stream.message().await {
+				Err(e) => break error!("error receiving change: {}", e),
 				Ok(v) => match v {
+					None => break warn!("stream closed"),
 					Some(operation) => {
 						match serde_json::from_str(&operation.opseq) {
-							Ok(op) => {
-								let res = { factory.lock().unwrap().process(op) };
-								match res {
-									Ok(x) => callback(x),
-									Err(e) => break error!("desynched: {}", e),
-								}
-							},
 							Err(e) => break error!("could not deserialize opseq: {}", e),
+							Ok(op) => match factory.process(op).await {
+								Err(e) => break error!("desynched: {}", e),
+								Ok(x) => callback(x),
+							},
 						}
 					}
-					None => break warn!("stream closed"),
 				},
-				Err(e) => break error!("error receiving change: {}", e),
 			}
 		}
 	}
-
-	pub fn content(&self) -> String {
-		let factory = self.factory.lock().unwrap();
-		factory.content()
-	}
 }

src/lib/opfactory.rs

@@ -1,4 +1,6 @@
 use operational_transform::{OperationSeq, OTError};
+use tokio::sync::{mpsc, watch, oneshot};
+use tracing::error;
 
 #[derive(Clone)]
 pub struct OperationFactory {
@@ -30,11 +32,11 @@ impl OperationFactory {
 
 	pub fn insert(&mut self, txt: &str, pos: u64) -> Result<OperationSeq, OTError> {
 		let mut out = OperationSeq::default();
-		let len = self.content.len() as u64;
+		let total = self.content.len() as u64;
 		out.retain(pos);
 		out.insert(txt);
-		out.retain(len - pos);
-		self.content = out.apply(&self.content)?; // TODO does applying mutate the OpSeq itself?
+		out.retain(total - pos);
+		self.content = out.apply(&self.content)?;
 		Ok(out)
 	}
 
@@ -44,7 +46,7 @@ impl OperationFactory {
 		out.retain(pos - count);
 		out.delete(count);
 		out.retain(len - pos);
-		self.content = out.apply(&self.content)?; // TODO does applying mutate the OpSeq itself?
+		self.content = out.apply(&self.content)?;
 		Ok(out)
 	}
 
@@ -54,7 +56,7 @@ impl OperationFactory {
 		out.retain(pos);
 		out.delete(count);
 		out.retain(len - (pos+count));
-		self.content = out.apply(&self.content)?; // TODO does applying mutate the OpSeq itself?
+		self.content = out.apply(&self.content)?;
 		Ok(out)
 	}
 
@@ -63,3 +65,119 @@ impl OperationFactory {
 		Ok(self.content.clone())
 	}
 }
+
+
+pub struct AsyncFactory {
+	run: watch::Sender<bool>,
+	ops: mpsc::Sender<OpMsg>,
+	content: watch::Receiver<String>,
+}
+
+impl Drop for AsyncFactory {
+	fn drop(&mut self) {
+		self.run.send(false).unwrap_or(());
+	}
+}
+
+impl AsyncFactory {
+	pub fn new(init: Option<String>) -> Self {
+		let (run_tx, run_rx) = watch::channel(true);
+		let (ops_tx, ops_rx) = mpsc::channel(64); // TODO hardcoded size
+		let (txt_tx, txt_rx) = watch::channel("".into());
+
+		let worker = AsyncFactoryWorker {
+			factory: OperationFactory::new(init),
+			ops: ops_rx,
+			run: run_rx,
+			content: txt_tx,
+		};
+
+		tokio::spawn(async move { worker.work().await });
+
+		AsyncFactory { run: run_tx, ops: ops_tx, content: txt_rx }
+	}
+
+	pub async fn insert(&self, txt: String, pos: u64) -> Result<OperationSeq, OTError> {
+		let (tx, rx) = oneshot::channel();
+		self.ops.send(OpMsg::Exec(OpWrapper::Insert(txt, pos), tx)).await.unwrap();
+		rx.await.unwrap()
+	}
+
+	pub async fn delete(&self, pos: u64, count: u64) -> Result<OperationSeq, OTError> {
+		let (tx, rx) = oneshot::channel();
+		self.ops.send(OpMsg::Exec(OpWrapper::Delete(pos, count), tx)).await.unwrap();
+		rx.await.unwrap()
+	}
+
+	pub async fn cancel(&self, pos: u64, count: u64) -> Result<OperationSeq, OTError> {
+		let (tx, rx) = oneshot::channel();
+		self.ops.send(OpMsg::Exec(OpWrapper::Cancel(pos, count), tx)).await.unwrap();
+		rx.await.unwrap()
+	}
+
+	pub async fn process(&self, opseq: OperationSeq) -> Result<String, OTError> {
+		let (tx, rx) = oneshot::channel();
+		self.ops.send(OpMsg::Process(opseq, tx)).await.unwrap();
+		rx.await.unwrap()
+	}
+}
+
+
+
+
+
+#[derive(Debug)]
+enum OpMsg {
+	Exec(OpWrapper, oneshot::Sender<Result<OperationSeq, OTError>>),
+	Process(OperationSeq, oneshot::Sender<Result<String, OTError>>),
+}
+
+#[derive(Debug)]
+enum OpWrapper {
+	Insert(String, u64),
+	Delete(u64, u64),
+	Cancel(u64, u64),
+}
+
+struct AsyncFactoryWorker {
+	factory: OperationFactory,
+	ops: mpsc::Receiver<OpMsg>,
+	run: watch::Receiver<bool>,
+	content: watch::Sender<String>
+}
+
+impl AsyncFactoryWorker {
+	async fn work(mut self) {
+		while *self.run.borrow() {
+			tokio::select! { // periodically check run so that we stop cleanly
+
+				recv = self.ops.recv() => {
+					match recv {
+						Some(msg) => {
+							match msg {
+								OpMsg::Exec(op, tx) => tx.send(self.exec(op)).unwrap_or(()),
+								OpMsg::Process(opseq, tx) => tx.send(self.factory.process(opseq)).unwrap_or(()),
+							}
+							if let Err(e) = self.content.send(self.factory.content()) {
+								error!("error updating content: {}", e);
+								break;
+							}
+						},
+						None => break,
+					}
+				},
+
+				_ = tokio::time::sleep(std::time::Duration::from_secs(1)) => {},
+
+			};
+		}
+	}
+
+	fn exec(&mut self, op: OpWrapper) -> Result<OperationSeq, OTError> {
+		match op {
+			OpWrapper::Insert(txt, pos) => Ok(self.factory.insert(&txt, pos)?),
+			OpWrapper::Delete(pos, count) => Ok(self.factory.delete(pos, count)?),
+			OpWrapper::Cancel(pos, count) => Ok(self.factory.cancel(pos, count)?),
+		}
+	}
+}