pub struct ReadBuf<'a> { /* private fields */ }
Expand description
A wrapper around a byte buffer that 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 ]
Implementations
sourceimpl<'a> ReadBuf<'a>
impl<'a> ReadBuf<'a>
sourcepub fn new(buf: &'a mut [u8]) -> ReadBuf<'a>
pub fn new(buf: &'a mut [u8]) -> ReadBuf<'a>
Creates a new ReadBuf
from a fully initialized buffer.
sourcepub fn uninit(buf: &'a mut [MaybeUninit<u8>]) -> ReadBuf<'a>
pub fn uninit(buf: &'a mut [MaybeUninit<u8>]) -> ReadBuf<'a>
Creates a new ReadBuf
from a fully uninitialized buffer.
Use assume_init
if part of the buffer is known to be already initialized.
sourcepub fn filled(&self) -> &[u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn filled(&self) -> &[u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a shared reference to the filled portion of the buffer.
sourcepub fn filled_mut(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn filled_mut(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a mutable reference to the filled portion of the buffer.
sourcepub fn initialized(&self) -> &[u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn initialized(&self) -> &[u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a shared reference to the initialized portion of the buffer.
This includes the filled portion.
sourcepub fn initialized_mut(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn initialized_mut(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a mutable reference to the initialized portion of the buffer.
This includes the filled portion.
sourcepub unsafe fn unfilled_mut(&mut self) -> &mut [MaybeUninit<u8>]
pub unsafe fn unfilled_mut(&mut self) -> &mut [MaybeUninit<u8>]
Returns a mutable reference to the unfilled part of the buffer without ensuring that it has been fully initialized.
Safety
The caller must not de-initialize portions of the buffer that have already been initialized.
sourcepub fn uninitialized_mut(&mut self) -> &mut [MaybeUninit<u8>]
pub fn uninitialized_mut(&mut self) -> &mut [MaybeUninit<u8>]
Returns a mutable reference to the uninitialized part of the buffer.
It is safe to uninitialize any of these bytes.
sourcepub fn initialize_unfilled(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn initialize_unfilled(&mut self) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a mutable reference to the unfilled part of the buffer, ensuring it is fully initialized.
Since ReadBuf
tracks the region of the buffer that has been initialized, this is effectively “free” after
the first use.
sourcepub fn initialize_unfilled_to(&mut self, n: usize) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
pub fn initialize_unfilled_to(&mut self, n: usize) -> &mut [u8]ⓘNotable traits for &[u8]impl Read for &[u8]impl Write for &mut [u8]
Returns a mutable reference to the first n
bytes of the unfilled part of the buffer, ensuring it is
fully initialized.
Panics
Panics if self.remaining()
is less than n
.
sourcepub fn remaining(&self) -> usize
pub fn remaining(&self) -> usize
Returns the number of bytes at the end of the slice that have not yet been filled.
sourcepub fn clear(&mut self) -> &mut Self
pub fn clear(&mut self) -> &mut Self
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.
sourcepub fn add_filled(&mut self, n: usize) -> &mut Self
pub fn add_filled(&mut self, n: usize) -> &mut Self
Increases the size of the filled region of the buffer.
The number of initialized bytes is not changed.
Panics
Panics if the filled region of the buffer would become larger than the initialized region.
sourcepub fn set_filled(&mut self, n: usize) -> &mut Self
pub fn set_filled(&mut self, n: usize) -> &mut Self
Sets the size of the filled region of the buffer.
The number of initialized bytes is not changed.
Note that this can be used to shrink the filled region of the buffer in addition to growing it (for
example, by a Read
implementation that compresses data in-place).
Panics
Panics if the filled region of the buffer would become larger than the initialized region.
sourcepub unsafe fn assume_init(&mut self, n: usize) -> &mut Self
pub unsafe fn assume_init(&mut self, n: usize) -> &mut Self
Asserts that the first n
unfilled bytes of the buffer are initialized.
ReadBuf
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.
sourcepub fn append(&mut self, buf: &[u8])
pub fn append(&mut self, buf: &[u8])
Appends data to the buffer, advancing the written position and possibly also the initialized position.
Panics
Panics if self.remaining()
is less than buf.len()
.
sourcepub fn filled_len(&self) -> usize
pub fn filled_len(&self) -> usize
Returns the amount of bytes that have been filled.
sourcepub fn initialized_len(&self) -> usize
pub fn initialized_len(&self) -> usize
Returns the amount of bytes that have been initialized.
Trait Implementations
Auto Trait Implementations
impl<'a> RefUnwindSafe for ReadBuf<'a>
impl<'a> Send for ReadBuf<'a>
impl<'a> Sync for ReadBuf<'a>
impl<'a> Unpin for ReadBuf<'a>
impl<'a> !UnwindSafe for ReadBuf<'a>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more