Struct Writer 

pub struct Writer<'a> {
    buf: &'a mut [MaybeUninit<u8>],
}

MQTT wire format writer.

Fields

buf: &'a mut [MaybeUninit<u8>]

Implementations

impl<'a> Writer<'a>

pub const fn new(buf: &'a mut [u8]) -> Self

Creates a new writer over an initialized buffer.

pub const fn new_uninit(buf: &'a mut [MaybeUninit<u8>]) -> Self

Creates a new writer over the given buffer.

pub const fn into_uninit(self) -> &'a mut [MaybeUninit<u8>]

Returns the remaining unwritten portion of the buffer.

const unsafe fn split_off_at_mut_unchecked( &mut self, index: usize, ) -> &'a mut [MaybeUninit<u8>]

Splits off a prefix of the buffer for writing, returning a mutable slice to it and advancing self.buf past it.

Safety

The caller must guarantee that index is a valid split point of self.buf, and that the returned slice is fully written before any further use of self.

const unsafe fn write_slice_unchecked(&mut self, bytes: &[u8])

Writes a copy of the given slice into the buffer.

Safety

The caller must guarantee that self.buf has at least bytes.len() bytes available.

pub const fn write_slice(&mut self, bytes: &[u8]) -> Result<(), EncodeError>

Writes a copy of the given slice into the buffer.

Errors

Returns EncodeError::InsufficientSpace if the buffer cannot fit the bytes.

pub const fn u8(&mut self, value: u8) -> Result<(), EncodeError>

Writes a single byte.

Errors

Returns EncodeError::InsufficientSpace if the buffer is full.

pub const fn u16(&mut self, value: u16) -> Result<(), EncodeError>

Writes a big-endian u16.

Errors

Returns EncodeError::InsufficientSpace if the buffer has fewer than 2 bytes free.

pub const fn u32(&mut self, value: u32) -> Result<(), EncodeError>

Writes a big-endian u32.

Errors

Returns EncodeError::InsufficientSpace if the buffer has fewer than 4 bytes free.

pub const fn vbi(&mut self, value: Vbi) -> Result<(), EncodeError>

Writes a Variable Byte Integer (1–4 bytes).

Errors

Returns EncodeError::InsufficientSpace if the buffer cannot fit the encoded value.

pub const fn binary(&mut self, bytes: &MqttBytes) -> Result<(), EncodeError>

Writes a length-prefixed binary data.

Errors

Returns EncodeError::InsufficientSpace if the buffer cannot fit the length prefix and data.

pub const fn string(&mut self, s: &MqttStr) -> Result<(), EncodeError>

Writes a length-prefixed UTF-8 string with additional MQTT validation.

Errors

Returns EncodeError::InsufficientSpace if the buffer cannot fit the string.