firmware: extract io::Cursor into its own file.

Also remove unused io::CursorError.

artiq/firmware/libio/cursor.rs

@@ -0,0 +1,86 @@
+use {Read, Write};
+
+#[derive(Debug, Clone)]
+pub struct Cursor<T> {
+    inner: T,
+    pos:   usize
+}
+
+impl<T> Cursor<T> {
+    #[inline]
+    pub fn new(inner: T) -> Cursor<T> {
+        Cursor { inner, pos: 0 }
+    }
+
+    #[inline]
+    pub fn into_inner(self) -> T {
+        self.inner
+    }
+
+    #[inline]
+    pub fn get_ref(&self) -> &T {
+        &self.inner
+    }
+
+    #[inline]
+    pub fn get_mut(&mut self) -> &mut T {
+        &mut self.inner
+    }
+
+    #[inline]
+    pub fn position(&self) -> usize {
+        self.pos
+    }
+
+    #[inline]
+    pub fn set_position(&mut self, pos: usize) {
+        self.pos = pos
+    }
+}
+
+impl<T: AsRef<[u8]>> Read for Cursor<T> {
+    type ReadError = !;
+
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::ReadError> {
+        let data = &self.inner.as_ref()[self.pos..];
+        let len = buf.len().min(data.len());
+        buf[..len].copy_from_slice(&data[..len]);
+        self.pos += len;
+        Ok(len)
+    }
+}
+
+impl<'a> Write for Cursor<&'a mut [u8]> {
+    type WriteError = !;
+    type FlushError = !;
+
+    fn write(&mut self, buf: &[u8]) -> Result<usize, Self::WriteError> {
+        let data = &mut self.inner[self.pos..];
+        let len  = buf.len().min(data.len());
+        data[..len].copy_from_slice(&buf[..len]);
+        self.pos += len;
+        Ok(len)
+    }
+
+    #[inline]
+    fn flush(&mut self) -> Result<(), Self::FlushError> {
+        Ok(())
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl Write for Cursor<::alloc::Vec<u8>> {
+    type WriteError = !;
+    type FlushError = !;
+
+    #[inline]
+    fn write(&mut self, buf: &[u8]) -> Result<usize, Self::WriteError> {
+        self.inner.extend_from_slice(buf);
+        Ok(buf.len())
+    }
+
+    #[inline]
+    fn flush(&mut self) -> Result<(), Self::FlushError> {
+        Ok(())
+    }
+}

artiq/firmware/libio/lib.rs

@@ -11,9 +11,12 @@ extern crate byteorder;
 use core::result;
 use core::fmt;
 
+mod cursor;
 #[cfg(feature = "byteorder")]
 pub mod proto;
 
+pub use cursor::Cursor;
+
 pub type Result<T, E> = result::Result<T, Error<E>>;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -152,93 +155,3 @@ impl<'a> Write for alloc::Vec<u8> {
         Ok(())
     }
 }
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum CursorError {
-    EndOfBuffer
-}
-
-#[derive(Debug, Clone)]
-pub struct Cursor<T> {
-    inner: T,
-    pos:   usize
-}
-
-impl<T> Cursor<T> {
-    #[inline]
-    pub fn new(inner: T) -> Cursor<T> {
-        Cursor { inner, pos: 0 }
-    }
-
-    #[inline]
-    pub fn into_inner(self) -> T {
-        self.inner
-    }
-
-    #[inline]
-    pub fn get_ref(&self) -> &T {
-        &self.inner
-    }
-
-    #[inline]
-    pub fn get_mut(&mut self) -> &mut T {
-        &mut self.inner
-    }
-
-    #[inline]
-    pub fn position(&self) -> usize {
-        self.pos
-    }
-
-    #[inline]
-    pub fn set_position(&mut self, pos: usize) {
-        self.pos = pos
-    }
-}
-
-impl<T: AsRef<[u8]>> Read for Cursor<T> {
-    type ReadError = !;
-
-    fn read(&mut self, buf: &mut [u8]) -> result::Result<usize, Self::ReadError> {
-        let data = &self.inner.as_ref()[self.pos..];
-        let len = buf.len().min(data.len());
-        buf[..len].copy_from_slice(&data[..len]);
-        self.pos += len;
-        Ok(len)
-    }
-}
-
-impl<'a> Write for Cursor<&'a mut [u8]> {
-    type WriteError = !;
-    type FlushError = !;
-
-    fn write(&mut self, buf: &[u8]) -> result::Result<usize, Self::WriteError> {
-        let data = &mut self.inner[self.pos..];
-        let len  = buf.len().min(data.len());
-        data[..len].copy_from_slice(&buf[..len]);
-        self.pos += len;
-        Ok(len)
-    }
-
-    #[inline]
-    fn flush(&mut self) -> result::Result<(), Self::FlushError> {
-        Ok(())
-    }
-}
-
-#[cfg(feature = "alloc")]
-impl Write for Cursor<::alloc::Vec<u8>> {
-    type WriteError = !;
-    type FlushError = !;
-
-    #[inline]
-    fn write(&mut self, buf: &[u8]) -> result::Result<usize, Self::WriteError> {
-        self.inner.extend_from_slice(buf);
-        Ok(buf.len())
-    }
-
-    #[inline]
-    fn flush(&mut self) -> result::Result<(), Self::FlushError> {
-        Ok(())
-    }
-}