Starting to think of a stream architecture

Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "rdsp"
+version = "0.1.0"

src/lib.rs

@@ -1,14 +1 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+mod stream;

src/stream.rs

@@ -0,0 +1,78 @@
+// Streams moves data from one place to another
+// Implementation of double buffered stream interfaces
+
+use std::sync::Arc;
+
+struct StreamInner<T: Sized> {
+    // Underlying buffer of data
+    buffer: Box<[T]>,
+    buffer_size: usize,
+
+    // Current half of the buffer that is on the writer's side
+    current_write: bool,
+    available: usize,
+    written: usize,
+}
+
+struct StreamReader<T: Sized> {
+    inner: Arc<StreamInner<T>>,
+}
+
+struct StreamWriter<T: Sized> {
+    inner: Arc<StreamInner<T>>,
+}
+
+impl<T: Sized + Clone> StreamInner<T> {
+    pub fn new(buffer_size: usize, default: T) -> Self {
+        Self {
+            buffer: vec![default; buffer_size * 2].into_boxed_slice(),
+            buffer_size,
+            current_write: false,
+            available: 0,
+            written: 0,
+        }
+    }
+
+    pub fn get_read_slice(&self) -> &[T] {
+        let offset = if self.current_write {
+            0
+        } else {
+            self.buffer_size
+        };
+
+        &self.buffer[offset..(offset + self.buffer_size)]
+    }
+
+    pub fn get_write_slice(&mut self) -> &mut [T] {
+        let offset = if self.current_write {
+            self.buffer_size
+        } else {
+            0
+        };
+
+        &mut self.buffer[offset..offset + self.buffer_size]
+    }
+}
+
+enum StreamWriteError {
+    BufferFull,
+}
+
+impl<T: Sized> StreamWriter<T> {
+    pub fn write(&mut self, data: T) -> Result<(), StreamWriteError> {
+        if self.inner.written == self.inner.buffer_size {
+            Err(StreamWriteError::BufferFull)
+        } else {
+            unsafe {
+                *self.inner.get_write_slice()[self.inner.written].assume_init_mut() = data;
+                self.inner.a
+            }
+            self.inner.written += 1;
+            Ok(())
+        }
+    }
+}
+
+pub fn stream<T: Sized>(buffer_size: usize) -> (StreamWriter<T>, StreamReader<T>) {
+    todo!()
+}