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
Creates a new ReadBuf
from a fully initialized buffer.
Creates a new ReadBuf
from a fully uninitialized buffer.
Use assume_init
if part of the buffer is known to be already initialized.
Returns the total capacity of the buffer.
pub fn filled_mut(&mut self) -> &mut [u8]ⓘ
pub fn filled_mut(&mut self) -> &mut [u8]ⓘ
Returns a mutable reference to the filled portion of the buffer.
pub fn initialized(&self) -> &[u8]ⓘ
pub fn initialized(&self) -> &[u8]ⓘ
Returns a shared reference to the initialized portion of the buffer.
This includes the filled portion.
pub fn initialized_mut(&mut self) -> &mut [u8]ⓘ
pub fn initialized_mut(&mut self) -> &mut [u8]ⓘ
Returns a mutable reference to the initialized portion of the buffer.
This includes the filled portion.
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.
Returns a mutable reference to the uninitialized part of the buffer.
It is safe to uninitialize any of these bytes.
pub fn initialize_unfilled(&mut self) -> &mut [u8]ⓘ
pub fn initialize_unfilled(&mut self) -> &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.
pub fn initialize_unfilled_to(&mut self, n: usize) -> &mut [u8]ⓘ
pub fn initialize_unfilled_to(&mut self, n: usize) -> &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
.
Returns the number of bytes at the end of the slice that have not yet been filled.
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.
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.
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.
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.
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()
.
Returns the amount of bytes that have been filled.
Returns the amount of bytes that have been initialized.