Struct TxQueue 

pub struct TxQueue<const N: usize = 16, const FRAME: usize = MAX_RESEND_FRAME_LEN> { /* private fields */ }

Fixed-capacity, priority-ordered transmit queue owned by the Mac coordinator.

The TxQueue serializes all outgoing frames — MAC ACKs, forwarded frames, retransmissions, and application sends — into a single ordered sequence for delivery to the radio one at a time. Entries are serviced in TxPriority order, with FIFO ordering within each class.

The queue capacity N is a compile-time constant (default DEFAULT_TX). Attempts to enqueue beyond capacity fail with crate::CapacityError, propagated as SendError::QueueFull or MacError::QueueFull. Choose N large enough to absorb the worst-case burst: a forwarded frame, its MAC ACK, plus any application sends already queued, plus the retransmit backlog.

Internally the queue is an unsorted heapless::Vec<QueuedTx, N>. The dequeue operation does a linear scan for the highest-priority, lowest-sequence entry whose not_before_ms has elapsed, which is O(N) — acceptable for the small N typical in embedded deployments.

Implementations

impl<const N: usize, const FRAME: usize> TxQueue<N, FRAME>

pub fn new() -> Self

Create an empty transmission queue.

pub fn len(&self) -> usize

Return the number of queued transmissions.

pub fn is_empty(&self) -> bool

Return whether no transmissions are queued.

pub fn enqueue( &mut self, priority: TxPriority, frame: &[u8], receipt: Option<SendReceipt>, identity_id: Option<LocalIdentityId>, ) -> Result<u32, CapacityError>

Enqueue a frame and return its internal sequence number.

pub fn enqueue_with_state( &mut self, priority: TxPriority, frame: &[u8], receipt: Option<SendReceipt>, identity_id: Option<LocalIdentityId>, not_before_ms: u64, cad_attempts: u8, forward_deferrals: u8, ) -> Result<u32, CapacityError>

Enqueue a frame with explicit timer and CAD state.

pub fn pop_next(&mut self) -> Option<QueuedTx<FRAME>>

Remove and return the highest-priority queued frame.

pub fn earliest_not_before_ms(&self) -> Option<u64>

Return the earliest not_before_ms across all entries, if any are deferred.

pub fn has_ready(&self, now_ms: u64) -> bool

Return whether the queue contains any entry that is ready to send now.

pub fn remove_first_matching( &mut self, predicate: impl FnMut(&QueuedTx<FRAME>) -> bool, ) -> Option<QueuedTx<FRAME>>

Remove and return the first queued frame matching predicate.

Trait Implementations

impl<const N: usize, const FRAME: usize> Clone for TxQueue<N, FRAME>

fn clone(&self) -> TxQueue<N, FRAME>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<const N: usize, const FRAME: usize> Debug for TxQueue<N, FRAME>

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

Formats the value using the given formatter.

impl<const N: usize, const FRAME: usize> Default for TxQueue<N, FRAME>

fn default() -> Self

Returns the “default value” for a type.