Struct MemoryBackend 

pub struct MemoryBackend { /* private fields */ }

In-process backend keeping job state in a single Mutex<Vec<…>>. Drop-in replacement for the bundled Queue storage; suitable for tests and single-node deployments. Replace with a remote backend for multi-pod use.

Memory bound: the pending queue is capped at MemoryBackend::max_pending (None = unlimited, default). Configure via MemoryBackend::with_max_pending to protect against unbounded growth when producers outpace consumers.

Implementations

impl MemoryBackend

pub fn new() -> MemoryBackend

pub fn with_max_pending(self, max: usize) -> MemoryBackend

Cap the pending vector at max jobs. Subsequent MemoryBackend::push calls that would exceed the cap return BackendError::Transport with the message queue full.

Use this to bound memory growth when a misconfigured retry loop or runaway producer would otherwise fill the heap.

impl MemoryBackend

pub fn dead_letters(&self) -> Vec<(JobId, String, Vec<u8>, u32)>

Snapshot of dead-letter jobs.

pub fn pending_count(&self) -> usize

Number of pending jobs across every queue.

pub fn reserved_count(&self) -> usize

Number of currently reserved jobs.

pub fn dedup_size(&self) -> usize

Number of active dedup keys. Useful for diagnostics — if this grows unboundedly your jobs are not reaching complete/dead_letter.

pub fn purge_dedup_key(&self, key: &str) -> bool

Drop a single dedup key out of band. Returns true if the key was present. Use this when a long retry tail needs to be cut short and a fresh push (same key) should be allowed to enqueue immediately.

Trait Implementations

impl Default for MemoryBackend

fn default() -> MemoryBackend

Returns the “default value” for a type.

impl QueueBackend for MemoryBackend

fn push<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, queue: &'life1 str, payload: &'life2 [u8], opts: PushOptions, ) -> Pin<Box<dyn Future<Output = Result<JobId, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, MemoryBackend: 'async_trait,

Push a payload onto a named queue, returning the job id.

fn reserve<'life0, 'life1, 'async_trait>( &'life0 self, queue: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Option<ReservedJob>, BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, MemoryBackend: 'async_trait,

Reserve the next ready job from a queue (FIFO, ready_at <= now).

fn complete<'life0, 'async_trait>( &'life0 self, id: JobId, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, MemoryBackend: 'async_trait,

Mark a reserved job complete — no retries, no DLQ entry.

fn fail<'life0, 'async_trait>( &'life0 self, id: JobId, retry_at: Option<Instant>, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, MemoryBackend: 'async_trait,

Mark a reserved job failed; if retry_at is set, requeue for that time.

fn dead_letter<'life0, 'async_trait>( &'life0 self, id: JobId, ) -> Pin<Box<dyn Future<Output = Result<(), BackendError>> + Send + 'async_trait>>

where 'life0: 'async_trait, MemoryBackend: 'async_trait,

Move a job to the dead-letter queue (terminal failure).