Struct AlignedBuf 

pub struct AlignedBuf<T> { /* private fields */ }

Growable byte buffer with base pointer aligned to max(align_of::<T>(), 8).

Uses u32 for len/cap (max ~4 GiB, matches Pos(u32)).

The buffer base is always at least 8-byte aligned, which guarantees correct alignment for all standard primitive types (up to i64/u64). If the root type T has stricter alignment, the buffer uses that instead.

Soundness

Allocation: Uses alloc::{alloc, realloc, dealloc} with a layout whose alignment is BUF_ALIGN. New regions are zero-filled. Allocation failure calls handle_alloc_error (never returns null silently).

Provenance exposure: After every grow or clone, the new pointer’s provenance is exposed via expose_provenance. This allows Near::get and session operations to recover the full allocation’s provenance using with_exposed_provenance when following self-relative offsets.

Send/Sync: The buffer is exclusively owned (no aliased mutable pointers). &AlignedBuf only provides &[u8] access. Both impls are sound.

Implementations

impl<T> AlignedBuf<T>

pub const fn new() -> Self

Create an empty buffer with a dangling aligned pointer.

pub fn with_capacity(capacity: u32) -> Self

Create an empty buffer pre-allocated to hold at least capacity bytes.

Trait Implementations

impl<T> Buf for AlignedBuf<T>

Available on crate feature alloc only.

const ALIGN: usize = Self::BUF_ALIGN

Buffer alignment guarantee.

fn empty() -> Self

Create an empty buffer (len = 0).

fn as_ptr(&self) -> *const u8

Raw pointer to the buffer start.

fn as_mut_ptr(&mut self) -> *mut u8

Mutable raw pointer to the buffer start.

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

View the buffer contents as a byte slice.

fn len(&self) -> u32

Current byte length.

fn capacity(&self) -> u32

Current capacity in bytes.

fn resize(&mut self, new_len: u32, fill: u8)

Grow or shrink the buffer, filling new bytes with fill.

fn reserve(&mut self, additional: u32)

Ensure at least additional bytes of spare capacity.

fn extend_from_slice(&mut self, data: &[u8])

Append bytes from a slice.

fn is_empty(&self) -> bool

Returns true if the buffer contains no bytes.

fn align_to(&mut self, align: usize)

Pad len up to the next multiple of align.

fn alloc<U: Flat>(&mut self) -> Pos

Align + allocate space for one U, return its position.

fn expose_provenance(&self)

Expose provenance so Near::get can recover it via with_exposed_provenance.

impl<T> Clone for AlignedBuf<T>

Available on crate feature alloc only.

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Default for AlignedBuf<T>

Available on crate feature alloc only.

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for AlignedBuf<T>

Available on crate feature alloc only.

fn drop(&mut self)

Executes the destructor for this type.

impl<T> Send for AlignedBuf<T>

Available on crate feature alloc only.

impl<T> Sync for AlignedBuf<T>

Available on crate feature alloc only.