Create helpers.rs

+ added struct to mock and async stream

foundation/src/helpers.rs

@@ -0,0 +1,115 @@
+use std::pin::Pin;
+use std::io::Error;
+use std::task::Poll;
+use std::sync::Mutex;
+use std::task::Context;
+
+use tokio::io::ReadBuf;
+use tokio::io::{AsyncRead, AsyncWrite};
+
+pub struct BufferStream {
+	buffer: Mutex<Vec<u8>>,
+}
+
+impl BufferStream {
+	pub fn new() -> BufferStream {
+		BufferStream {
+			buffer: Mutex::new(Vec::new()),
+		}
+	}
+}
+
+impl AsyncRead for BufferStream {
+	fn poll_read(
+		self: Pin<&mut Self>, 
+    _cx: &mut Context, 
+		buf: &mut ReadBuf<'_>
+	) -> Poll<Result<(), futures::io::Error>> {
+		let mut lock = self.buffer.lock().unwrap();
+
+		let a = if buf.remaining() < lock.len() {buf.remaining()} else {lock.len()};
+
+		buf.put_slice(&lock[..a]);
+
+		*lock = Vec::from(&lock[a..]);
+
+		Poll::Ready(Ok(()))
+	}
+}
+
+impl AsyncWrite for BufferStream {
+	fn poll_write(
+		self: Pin<&mut Self>, 
+		_cx: &mut Context<'_>, 
+		buf: &[u8]
+	) -> Poll<Result<usize, Error>> {
+		let mut lock = self.buffer.lock().unwrap();
+		lock.extend_from_slice(buf);
+		Poll::Ready(Ok(buf.len()))
+	}
+
+	fn poll_flush(
+			self: Pin<&mut Self>, 
+			_cx: &mut Context<'_>
+	) -> Poll<Result<(), Error>> {
+		Poll::Ready(Ok(()))
+	}
+
+	fn poll_shutdown(
+			self: Pin<&mut Self>, 
+			_cx: &mut Context<'_>
+	) -> Poll<Result<(), Error>> {
+		Poll::Ready(Ok(()))
+	}
+}
+
+#[cfg(test)]
+mod test {
+	
+	use tokio::io::split;
+	use tokio::io::AsyncWriteExt;
+
+	use crate::helpers::BufferStream;
+	use tokio::io::AsyncReadExt;
+
+	#[tokio::test]
+	async fn test_reading_and_writing() {
+		let stream = BufferStream::new();
+
+		let (mut rd, mut wd) = split(stream);
+
+		let _ = wd.write_all(b"1010").await;
+
+		let mut buf: [u8; 4] = [0; 4];
+
+		let _ = rd.read(&mut buf[..]).await;
+
+		println!("[test_reading_and_writing] {:?}", &buf[..]);
+
+		assert_eq!(b"1010", &buf[..]);
+	}
+
+
+	#[tokio::test]
+	async fn test_reading_small() {
+		let stream = BufferStream::new();
+
+		let (mut rd, mut wd) = split(stream);
+
+		let _ = wd.write_all(b"10100101").await;
+
+		let mut buf: [u8; 4] = [0; 4];
+
+		let _ = rd.read(&mut buf[..]).await;
+
+		println!("[test_reading_and_writing] {:?}", &buf[..]);
+
+		assert_eq!(b"1010", &buf[..]);
+
+		let _ = rd.read(&mut buf[..]).await;
+
+		println!("[test_reading_and_writing] {:?}", &buf[..]);
+
+		assert_eq!(b"0101", &buf[..]);
+	}
+}