Struct stm32l4xx_hal::dma::DMAFrame

pub struct DMAFrame<const N: usize> { /* private fields */ }

Data type for holding data frames for the Serial.

Internally used uninitialized storage, making this storage zero cost to create. It can also be used with, for example, heapless::pool to create a pool of serial frames.

Implementations

impl<const N: usize> DMAFrame<N>

pub const fn new() -> Self

Creates a new node for the Serial DMA

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

Gives a &mut [u8] slice to write into with the maximum size, the commit method must then be used to set the actual number of bytes written.

Note that this function internally first zeros the uninitialized part of the node’s buffer.

pub fn commit(&mut self, shrink_to: usize)

Used to shrink the current size of the frame, used in conjunction with write.

pub fn write_uninit(&mut self) -> &mut [MaybeUninit<u8>; N]

Gives an uninitialized &mut [MaybeUninit<u8>] slice to write into, the set_len method must then be used to set the actual number of bytes written.

pub unsafe fn set_len(&mut self, len: usize)

Used to set the current size of the frame, used in conjunction with write_uninit to have an interface for uninitialized memory. Use with care!

Safety

NOTE(unsafe): This must be set so that the final buffer is only referencing initialized memory.

pub fn write_slice(&mut self, buf: &[u8]) -> usize

Used to write data into the node, and returns how many bytes were written from buf.

If the node is already partially filled, this will continue filling the node.

pub fn clear(&mut self)

Clear the node of all data making it empty

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

Returns a readable slice which maps to the buffers internal data

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

Returns a readable mutable slice which maps to the buffers internal data

pub fn len(&self) -> usize

Reads how many bytes are available

pub fn free(&self) -> usize

Reads how many bytes are free

pub fn max_len(&self) -> usize

Get the max length of the frame

pub fn is_empty(&self) -> bool

Checks if the frame is empty

Trait Implementations

impl<const N: usize> AsRef<[u8]> for DMAFrame<N>

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl<const N: usize> Debug for DMAFrame<N>

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

Formats the value using the given formatter.

impl<const N: usize> Default for DMAFrame<N>

fn default() -> Self

Returns the “default value” for a type.

impl<const N: usize> Write for DMAFrame<N>

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.