dope_sys/io/
raw.rs

1use crate::io::socket::msg;
2/// # Safety
3/// The header and all pointees stay initialized, immutable, and live through `'a`.
4/// Its iovec count fits the target and its byte sum is at most `i32::MAX`.
5pub unsafe trait Message<'a> {
6    fn header(self) -> &'a msg::Header;
7}
8
9/// A byte range that retains its owner through unchecked prefix projection.
10///
11/// # Safety
12/// `prefix` must preserve the original owner and its admitted initialized bytes.
13pub unsafe trait Buffer: Sized {
14    /// # Safety
15    /// `len` must not exceed this buffer's initialized extent.
16    unsafe fn prefix(self, len: usize) -> Self;
17
18    /// Decodes an admitted completion, reading `errno` only for minus one.
19    ///
20    /// # Safety
21    /// `raw` is -1 or a nonnegative count within this owner's initialized extent.
22    unsafe fn try_native<E: From<crate::Errno>>(
23        self,
24        raw: libc::ssize_t,
25        errno: impl FnOnce() -> crate::Errno,
26    ) -> Result<Self, E> {
27        if raw == -1 {
28            return Err(E::from(errno()));
29        }
30        // SAFETY: the caller retains this completed count's admitted extent proof.
31        Ok(unsafe { self.prefix(raw as usize) })
32    }
33}
34
35// SAFETY: slice length is its initialized byte extent.
36unsafe impl Buffer for &[u8] {
37    unsafe fn prefix(self, len: usize) -> Self {
38        unsafe { self.get_unchecked(..len) }
39    }
40}
41
42// SAFETY: the exclusive slice retains its initialized byte extent.
43unsafe impl Buffer for &mut [u8] {
44    unsafe fn prefix(self, len: usize) -> Self {
45        unsafe { self.get_unchecked_mut(..len) }
46    }
47}
dope_sys/io/raw.rs

dope_sys/io/
raw.rs
