diff options
Diffstat (limited to 'vendor/rustix/src/maybe_polyfill/no_std/io/mod.rs')
-rw-r--r-- | vendor/rustix/src/maybe_polyfill/no_std/io/mod.rs | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/rustix/src/maybe_polyfill/no_std/io/mod.rs b/vendor/rustix/src/maybe_polyfill/no_std/io/mod.rs new file mode 100644 index 0000000..f0ad750 --- /dev/null +++ b/vendor/rustix/src/maybe_polyfill/no_std/io/mod.rs @@ -0,0 +1,107 @@ +//! The following is derived from Rust's +//! library/std/src/sys/unix/io.rs +//! dca3f1b786efd27be3b325ed1e01e247aa589c3b. +//! +//! All code in this file is licensed MIT or Apache 2.0 at your option. + +#![allow(unsafe_code)] +use crate::backend::c; +#[cfg(not(linux_raw))] +use c::size_t as __kernel_size_t; +use core::marker::PhantomData; +use core::slice; +#[cfg(linux_raw)] +use linux_raw_sys::general::__kernel_size_t; + +/// <https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html> +#[derive(Copy, Clone)] +#[repr(transparent)] +pub struct IoSlice<'a> { + vec: c::iovec, + _p: PhantomData<&'a [u8]>, +} + +impl<'a> IoSlice<'a> { + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.new> + #[inline] + pub fn new(buf: &'a [u8]) -> IoSlice<'a> { + IoSlice { + vec: c::iovec { + iov_base: buf.as_ptr() as *mut u8 as *mut c::c_void, + iov_len: buf.len() as _, + }, + _p: PhantomData, + } + } + + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance> + #[inline] + pub fn advance(&mut self, n: usize) { + if self.vec.iov_len < n as _ { + panic!("advancing IoSlice beyond its length"); + } + + unsafe { + // `__kernel_size_t` will always have the same size as `usize`, but it is a `u32` on + // 32-bit platforms and `u64` on 64-bit platforms when using `linux_raw` backend + self.vec.iov_len -= n as __kernel_size_t; + self.vec.iov_base = self.vec.iov_base.add(n); + } + } + + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.as_slice> + #[inline] + pub fn as_slice(&self) -> &[u8] { + unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len as usize) } + } +} + +/// <https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html> +#[repr(transparent)] +pub struct IoSliceMut<'a> { + vec: c::iovec, + _p: PhantomData<&'a mut [u8]>, +} + +impl<'a> IoSliceMut<'a> { + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.new> + #[inline] + pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> { + IoSliceMut { + vec: c::iovec { + iov_base: buf.as_mut_ptr() as *mut c::c_void, + iov_len: buf.len() as _, + }, + _p: PhantomData, + } + } + + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance> + #[inline] + pub fn advance(&mut self, n: usize) { + if self.vec.iov_len < n as _ { + panic!("advancing IoSliceMut beyond its length"); + } + + unsafe { + // `__kernel_size_t` will always have the same size as `usize`, but it is a `u32` on + // 32-bit platforms and `u64` on 64-bit platforms when using `linux_raw` backend + self.vec.iov_len -= n as __kernel_size_t; + self.vec.iov_base = self.vec.iov_base.add(n); + } + } + + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.as_slice> + #[inline] + pub fn as_slice(&self) -> &[u8] { + unsafe { slice::from_raw_parts(self.vec.iov_base as *mut u8, self.vec.iov_len as usize) } + } + + /// <https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.as_slice_mut> + #[inline] + pub fn as_mut_slice(&mut self) -> &mut [u8] { + unsafe { + slice::from_raw_parts_mut(self.vec.iov_base as *mut u8, self.vec.iov_len as usize) + } + } +} |