artiq-zynq/src/libio/cursor.rs

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Rust
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use core_io::{Read, Write, Error as IoError};
#[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> {
fn read(&mut self, buf: &mut [u8]) -> Result<usize, IoError> {
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 Write for Cursor<&mut [u8]> {
fn write(&mut self, buf: &[u8]) -> Result<usize, IoError> {
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<(), IoError> {
Ok(())
}
}
#[cfg(feature = "alloc")]
impl Write for Cursor<::alloc::Vec<u8>> {
#[inline]
fn write(&mut self, buf: &[u8]) -> Result<usize, IoError> {
self.inner.extend_from_slice(buf);
Ok(buf.len())
}
#[inline]
fn flush(&mut self) -> Result<(), IoError> {
Ok(())
}
}