Trait IoBufMut 

pub unsafe trait IoBufMut: IoBuf + SetLen {
    // Required method
    fn as_uninit(&mut self) -> &mut [MaybeUninit<u8>];

    // Provided methods
    fn buf_capacity(&mut self) -> usize { ... }
    fn buf_mut_ptr(&mut self) -> *mut u8 { ... }
    fn spare_mut(&mut self) -> &mut [MaybeUninit<u8>] { ... }
    fn as_mut_slice(&mut self) -> &mut [u8]  { ... }
    fn uninit(self) -> Uninit<Self>
       where Self: Sized { ... }
}

An IoBuf that can also be written into (i.e. used as a read destination).

Safety

as_uninit must expose the buffer’s full backing storage — the initialized prefix [0, buf_len) followed by writable spare [buf_len, capacity) — and the spare must be safe to write. Same address stability contract as IoBuf.

Required Methods

fn as_uninit(&mut self) -> &mut [MaybeUninit<u8>]

The full backing storage as possibly-uninitialized bytes: the initialized prefix [0, buf_len) plus the writable spare [buf_len, capacity).

The core accessor: capacity, the raw pointer, and the read-target spare all derive from it, and a reader fills spare_mut (a safe &mut [MaybeUninit<u8>]) instead of doing raw pointer arithmetic.

Provided Methods

fn buf_capacity(&mut self) -> usize

Total capacity (as_uninit().len()).

fn buf_mut_ptr(&mut self) -> *mut u8

Raw mutable pointer to the start of the backing storage: for a kernel/FFI read target (io_uring recv). Most code should prefer spare_mut.

Warning: make sure to read SAFETY rules of IoBufMut

fn spare_mut(&mut self) -> &mut [MaybeUninit<u8>]

The writable spare tail [buf_len, capacity) — the read destination.

fn as_mut_slice(&mut self) -> &mut [u8]

The initialized region [0, buf_len) as a mutable slice, for an in-place transform (e.g. decrypting a TLS record inside the very buffer it arrived in, no copy).

fn uninit(self) -> Uninit<Self>

where Self: Sized,

A read-target view of just the writable spare [buf_len, capacity).

Reading into it appends to self (the view’s offset 0 is self’s buf_len), so it’s how you accumulate on top of the overwrite-from-0 read primitive, e.g. read_exact loops read_owned(buf.uninit()). The owned analogue of compio’s Uninit.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl IoBufMut for BytesMut

impl IoBufMut for Vec<u8>

impl<B> IoBufMut for Uninit<B>

where B: IoBufMut,

impl<const N: usize> IoBufMut for ArrayBuf<N>