Struct std::io::BorrowedBuf

source ·
pub struct BorrowedBuf<'data> { /* private fields */ }
🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)
Expand description

A borrowed byte buffer which is incrementally filled and initialized.

This type is a sort of “double cursor”. It tracks three regions in the buffer: a region at the beginning of the buffer that has been logically filled with data, a region that has been initialized at some point but not yet logically filled, and a region at the end that is fully uninitialized. The filled region is guaranteed to be a subset of the initialized region.

In summary, the contents of the buffer can be visualized as:

[             capacity              ]
[ filled |         unfilled         ]
[    initialized    | uninitialized ]

A BorrowedBuf is created around some existing data (or capacity for data) via a unique reference (&mut). The BorrowedBuf can be configured (e.g., using clear or set_init), but cannot be directly written. To write into the buffer, use unfilled to create a BorrowedCursor. The cursor has write-only access to the unfilled portion of the buffer (you can think of it as a write-only iterator).

The lifetime 'data is a bound on the lifetime of the underlying data.

Implementations§

source§

impl<'data> BorrowedBuf<'data>

source

pub fn capacity(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns the total capacity of the buffer.

source

pub fn len(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns the length of the filled part of the buffer.

source

pub fn init_len(&self) -> usize

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns the length of the initialized part of the buffer.

source

pub fn filled(&self) -> &[u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a shared reference to the filled portion of the buffer.

source

pub fn filled_mut(&mut self) -> &mut [u8]

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a mutable reference to the filled portion of the buffer.

source

pub fn unfilled<'this>(&'this mut self) -> BorrowedCursor<'this>

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Returns a cursor over the unfilled part of the buffer.

source

pub fn clear(&mut self) -> &mut BorrowedBuf<'data>

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Clears the buffer, resetting the filled region to empty.

The number of initialized bytes is not changed, and the contents of the buffer are not modified.

source

pub unsafe fn set_init(&mut self, n: usize) -> &mut BorrowedBuf<'data>

🔬This is a nightly-only experimental API. (core_io_borrowed_buf #117693)

Asserts that the first n bytes of the buffer are initialized.

BorrowedBuf assumes that bytes are never de-initialized, so this method does nothing when called with fewer bytes than are already known to be initialized.

Safety

The caller must ensure that the first n unfilled bytes of the buffer have already been initialized.

Trait Implementations§

source§

impl Debug for BorrowedBuf<'_>

source§

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more
source§

impl<'data> From<&'data mut [MaybeUninit<u8>]> for BorrowedBuf<'data>

Create a new BorrowedBuf from an uninitialized buffer.

Use set_init if part of the buffer is known to be already initialized.

source§

fn from(buf: &'data mut [MaybeUninit<u8>]) -> BorrowedBuf<'data>

Converts to this type from the input type.
source§

impl<'data> From<&'data mut [u8]> for BorrowedBuf<'data>

Create a new BorrowedBuf from a fully initialized slice.

source§

fn from(slice: &'data mut [u8]) -> BorrowedBuf<'data>

Converts to this type from the input type.

Auto Trait Implementations§

§

impl<'data> RefUnwindSafe for BorrowedBuf<'data>

§

impl<'data> Send for BorrowedBuf<'data>

§

impl<'data> Sync for BorrowedBuf<'data>

§

impl<'data> Unpin for BorrowedBuf<'data>

§

impl<'data> !UnwindSafe for BorrowedBuf<'data>

Blanket Implementations§

source§

impl<T> Any for Twhere T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for Twhere T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for Twhere T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for Twhere U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.