Got a basic working version

Author: rakshith-ravi

src/connection/base_connection.rs

@@ -1,10 +1,13 @@
 use crate::{connection::Buffer, utils::Error};
 use async_trait::async_trait;
+use futures::channel::mpsc::{UnboundedReceiver, UnboundedSender};
 
 #[async_trait]
 pub trait BaseConnection {
 	async fn setup_connection(&mut self) -> Result<(), Error>;
-	async fn close_connection(&mut self) -> Result<(), Error>;
-	async fn send(&mut self, buffer: Buffer) -> Result<(), Error>;
-	async fn read_data(&mut self) -> Option<Buffer>;
+	async fn close_connection(&mut self);
+	async fn send(&mut self, buffer: Buffer);
+
+	fn get_data_receiver(&mut self) -> UnboundedReceiver<Buffer>;
+	fn clone_write_sender(&self) -> UnboundedSender<Buffer>;
 }

src/connection/inet_socket_connection.rs

@@ -1,85 +1,169 @@
 use crate::{
 	connection::{BaseConnection, Buffer},
-	utils::{Error, READ_BUFFER_SIZE},
+	utils::Error,
 };
 
-use async_std::{
-	net::{Shutdown, TcpStream},
-	prelude::*,
-};
+use async_std::{io::BufReader, net::TcpStream, prelude::*, task};
 use async_trait::async_trait;
 
+use futures::{
+	channel::{
+		mpsc::{unbounded, UnboundedReceiver, UnboundedSender},
+		oneshot::{channel, Sender},
+	},
+	future::{self, Either},
+};
+use futures_util::SinkExt;
+
 pub struct InetSocketConnection {
 	connection_setup: bool,
+	read_data_receiver: Option<UnboundedReceiver<Vec<u8>>>,
+	write_data_sender: Option<UnboundedSender<Vec<u8>>>,
+	close_sender: Option<UnboundedSender<()>>,
 	socket_path: String,
-	client: Option<TcpStream>,
 }
 
 impl InetSocketConnection {
 	pub fn new(socket_path: String) -> Self {
 		InetSocketConnection {
 			connection_setup: false,
+			read_data_receiver: None,
+			write_data_sender: None,
+			close_sender: None,
 			socket_path,
-			client: None,
 		}
 	}
 }
 
+async fn read_data_from_socket(
+	port: String,
+	init_sender: Sender<Result<(), Error>>,
+	mut read_sender: UnboundedSender<Vec<u8>>,
+	mut write_receiver: UnboundedReceiver<Vec<u8>>,
+	mut close_receiver: UnboundedReceiver<()>,
+) {
+	let result = TcpStream::connect(port).await;
+	if let Err(err) = result {
+		init_sender
+			.send(Err(Error::Internal(format!("{}", err))))
+			.unwrap_or(());
+		return;
+	}
+	let client = result.unwrap();
+	init_sender.send(Ok(())).unwrap_or(());
+	let reader = BufReader::new(&client);
+	let mut lines = reader.lines();
+	let mut read_future = lines.next();
+	let mut write_future = write_receiver.next();
+	let mut close_future = close_receiver.next();
+	let mut read_or_write_future = future::select(read_future, write_future);
+	while let Either::Left((read_write_future, next_close_future)) =
+		future::select(read_or_write_future, close_future).await
+	{
+		// Either a read or a write event has happened
+		close_future = next_close_future;
+		match read_write_future {
+			Either::Left((read_future_result, next_write_future)) => {
+				// Read event has happened
+				read_future = lines.next();
+				write_future = next_write_future;
+				read_or_write_future = future::select(read_future, write_future);
+				// Send the read data to the MPSC sender
+				if let Some(Ok(line)) = read_future_result {
+					let result = read_sender.send(line.as_bytes().to_vec()).await;
+					if let Err(err) = result {
+						println!("Error queing data from the socket to the module: {}", err);
+					}
+				}
+			}
+			Either::Right((write_future_result, next_read_future)) => {
+				// Write event has happened
+				read_future = next_read_future;
+				write_future = write_receiver.next();
+				read_or_write_future = future::select(read_future, write_future);
+				// Write the recieved bytes to the socket
+				if let Some(bytes) = write_future_result {
+					let mut socket = &client;
+					if let Err(err) = socket.write_all(&bytes).await {
+						println!("Error while sending data to socket: {}", err);
+					}
+				}
+			}
+		}
+	}
+	// Either a read, nor a write event has happened.
+	// This means the socket close event happened. Shutdown the socket and close any mpsc channels
+	drop(lines);
+	let result = read_sender.close().await;
+	if let Err(err) = result {
+		println!("Error closing the MPSC sender to queue data: {}", err);
+	}
+	write_receiver.close();
+	close_receiver.close();
+}
+
 #[async_trait]
 impl BaseConnection for InetSocketConnection {
 	async fn setup_connection(&mut self) -> Result<(), Error> {
 		if self.connection_setup {
 			panic!("Cannot call setup_connection() more than once!");
 		}
-		let result = TcpStream::connect(&self.socket_path).await;
-		if let Err(err) = result {
-			return Err(Error::Internal(format!("{}", err)));
-		}
-		self.client = Some(result.unwrap());
+		let (read_data_sender, read_data_receiver) = unbounded::<Vec<u8>>();
+		let (write_data_sender, write_data_receiver) = unbounded::<Vec<u8>>();
+		let (close_sender, close_receiver) = unbounded::<()>();
+		let (init_sender, init_receiver) = channel::<Result<(), Error>>();
+
+		self.read_data_receiver = Some(read_data_receiver);
+		self.write_data_sender = Some(write_data_sender);
+		self.close_sender = Some(close_sender);
+		let socket_path = self.socket_path.clone();
+
+		task::spawn(async {
+			read_data_from_socket(
+				socket_path,
+				init_sender,
+				read_data_sender,
+				write_data_receiver,
+				close_receiver,
+			)
+			.await;
+		});
 
 		self.connection_setup = true;
-		Ok(())
+		init_receiver.await.unwrap()
 	}
 
-	async fn close_connection(&mut self) -> Result<(), Error> {
-		if !self.connection_setup || self.client.is_none() {
+	async fn close_connection(&mut self) {
+		if !self.connection_setup || self.close_sender.is_none() {
 			panic!("Cannot close a connection that hasn't been established yet. Did you forget to call setup_connection()?");
 		}
-		let result = self.client.as_ref().unwrap().shutdown(Shutdown::Both);
-		if let Err(err) = result {
-			return Err(Error::Internal(format!("{}", err)));
+		let mut sender = &self.close_sender.as_ref().unwrap().clone();
+		if let Err(err) = sender.send(()).await {
+			println!("Error attempting to close connection: {}", err);
 		}
-		Ok(())
 	}
 
-	async fn send(&mut self, buffer: Buffer) -> Result<(), Error> {
-		if !self.connection_setup || self.client.is_none() {
+	async fn send(&mut self, buffer: Buffer) {
+		if !self.connection_setup || self.write_data_sender.is_none() {
 			panic!("Cannot send data to a connection that hasn't been established yet. Did you forget to await the call to setup_connection()?");
 		}
-		let result = self.client.as_mut().unwrap().write_all(&buffer).await;
-		if let Err(err) = result {
-			return Err(Error::Internal(format!("{}", err)));
+		let mut sender = &self.write_data_sender.as_ref().unwrap().clone();
+		if let Err(err) = sender.send(buffer).await {
+			println!("Error attempting to send data to connection: {}", err);
 		}
-		Ok(())
 	}
 
-	async fn read_data(&mut self) -> Option<Buffer> {
-		if self.client.is_none() {
-			None
-		} else {
-			let client = self.client.as_mut().unwrap();
-			let mut buffer = Vec::new();
-			let mut read_size = READ_BUFFER_SIZE;
-			while read_size > 0 {
-				let mut buf = [0u8; READ_BUFFER_SIZE];
-				let result = client.read(&mut buf).await;
-				if result.is_err() {
-					return None;
-				}
-				read_size = result.unwrap();
-				buffer.extend(buf[..read_size].into_iter());
-			}
-			Some(buffer)
+	fn get_data_receiver(&mut self) -> UnboundedReceiver<Buffer> {
+		if !self.connection_setup || self.read_data_receiver.is_none() {
+			panic!("Cannot get read sender to a connection that hasn't been established yet. Did you forget to await the call to setup_connection()?");
+		}
+		self.read_data_receiver.take().unwrap()
+	}
+
+	fn clone_write_sender(&self) -> UnboundedSender<Buffer> {
+		if !self.connection_setup || self.write_data_sender.is_none() {
+			panic!("Cannot get write sender of a connection that hasn't been established yet. Did you forget to await the call to setup_connection()?");
 		}
+		self.write_data_sender.as_ref().unwrap().clone()
 	}
 }