Struct DeadLetterQueue 

pub struct DeadLetterQueue { /* private fields */ }

Bounded dead-letter queue.

Stores rejected deltas for later inspection and retry. The queue is bounded to prevent unbounded memory growth from a flood of invalid deltas.

Implementations

impl DeadLetterQueue

pub fn new(capacity: usize) -> Self

Create a new DLQ with the given capacity.

pub fn enqueue( &mut self, peer_id: u64, user_id: u64, tenant_id: u64, delta: Vec<u8>, constraint: &Constraint, reason: String, hint: CompensationHint, ) -> Result<u64>

Enqueue a rejected delta with full auth context.

pub fn peek(&self) -> Option<&DeadLetter>

Peek at the oldest dead letter without removing it.

pub fn dequeue(&mut self) -> Option<DeadLetter>

Dequeue the oldest dead letter for retry or inspection.

pub fn get(&self, id: u64) -> Option<&DeadLetter>

Get a dead letter by ID.

pub fn remove(&mut self, id: u64) -> Option<DeadLetter>

Remove a dead letter by ID (e.g., after successful manual resolution).

pub fn purge_collection(&mut self, tenant_id: u64, collection: &str) -> usize

Drop every entry for (tenant_id, collection). Returns the number of entries removed. Called during collection hard-delete so stale rejected deltas don’t resurface if a collection of the same name is recreated inside the retention window’s shadow.

pub fn drain_peer(&mut self, peer_id: u64) -> Vec<DeadLetter>

Drain all entries for a specific peer.

pub fn len(&self) -> usize

Number of pending dead letters.

pub fn is_empty(&self) -> bool

pub fn capacity(&self) -> usize

Capacity of the queue.