Struct MessageDescriptor 

pub struct MessageDescriptor {
    pub region: RegionHandle,
    pub offset: u64,
    pub length: u32,
    /* private fields */
}

A zero-copy message descriptor.

Instead of copying message data into the ring buffer, a descriptor references data in a shared region. The receiver reads directly from the shared region using the offset and length.

TOCTOU Protection

Only Immutable or AppendOnly regions can use descriptors (ADR-087 Section 20.5). This prevents time-of-check-to-time-of-use attacks where a sender modifies shared data after the receiver reads the descriptor but before processing.

Fields

region: RegionHandle

Handle to the shared region containing the data.

offset: u64

Byte offset within the region.

length: u32

Length in bytes.

Implementations

impl MessageDescriptor

pub const SIZE: usize

Size of a descriptor in bytes.

pub const fn new(region: RegionHandle, offset: u64, length: u32) -> Self

Create a new message descriptor.

pub fn is_valid(&self) -> bool

Check if this descriptor is valid (non-null region, non-zero length).

pub fn to_bytes(&self) -> [u8; 24]

Convert to bytes for storage in ring buffer.

pub fn from_bytes(bytes: &[u8]) -> Option<Self>

Create from bytes read from ring buffer.

Trait Implementations

impl Clone for MessageDescriptor

fn clone(&self) -> MessageDescriptor

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MessageDescriptor

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

Formats the value using the given formatter.

impl PartialEq for MessageDescriptor

fn eq(&self, other: &MessageDescriptor) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for MessageDescriptor

impl Eq for MessageDescriptor

impl StructuralPartialEq for MessageDescriptor