Struct PrefixArena 

pub struct PrefixArena<'buf> { /* private fields */ }

A bump-style arena over caller-provided byte storage.

PrefixArena hands out slices from the front of the remaining buffer and keeps the rest available for later use. It only manages buffer boundaries; it does not track which bytes are initialized.

Implementations

impl<'buf> PrefixArena<'buf>

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

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

pub const fn len(&self) -> usize

Returns the number of bytes still available in the arena.

pub const fn is_empty(&self) -> bool

Returns true when no bytes remain available.

pub const fn view<'arena>(&'arena mut self) -> ArenaView<'arena, 'buf>

Borrows the currently remaining arena space through a temporary view.

pub fn take_prefix(&self, n: usize) -> &'buf mut [MaybeUninit<u8>]

Removes the first n bytes from the remaining arena and returns them.

The returned slice is uninitialized storage. The caller must initialize it before reading from it.

Panics

Panics if n > self.len().

pub unsafe fn take_prefix_unchecked(&self, n: usize) -> &'buf mut [u8]

Removes the first n bytes from the remaining arena and returns them as u8.

Safety

The caller must ensure both of the following:

• n <= self.len().
• Every returned byte is initialized before it is read as u8.

pub fn take_remaining(self) -> &'buf mut [MaybeUninit<u8>]

Returns all bytes that still remain in the arena and consumes self.

The returned slice is uninitialized storage. The caller must initialize it before reading from it.

pub fn init_prefix_with<F, E>(self, f: F) -> Result<&'buf mut [u8], E>

where F: FnOnce(&mut [u8]) -> Result<usize, E>,

Exposes the remaining arena as &mut [u8], lets f initialize a prefix, and then detaches that initialized prefix from the arena.

If f returns Err, the arena remains unchanged.

Safety

f must return the length of a prefix that it actually initialized.

Panics

Panics if f returns a length greater than the currently remaining size.

Trait Implementations

impl<'buf> From<&'buf mut [MaybeUninit<u8>]> for PrefixArena<'buf>

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

Converts to this type from the input type.

impl<'buf, const N: usize> From<&'buf mut [MaybeUninit<u8>; N]> for PrefixArena<'buf>

fn from(buffer: &'buf mut [MaybeUninit<u8>; N]) -> Self

Converts to this type from the input type.

impl<'buf> From<&'buf mut [u8]> for PrefixArena<'buf>

fn from(buffer: &'buf mut [u8]) -> Self

Converts to this type from the input type.

impl<'buf, const N: usize> From<&'buf mut [u8; N]> for PrefixArena<'buf>

fn from(buffer: &'buf mut [u8; N]) -> Self

Converts to this type from the input type.