Trait Queue 

pub trait Queue:
    Send
    + Sync
    + 'static {
    // Required methods
    fn driver(&self) -> &'static str;
    fn push(&self, job: QueuedJob) -> BoxFuture<'_, Result<String>>;
    fn pop<'a>(
        &'a self,
        queue: &'a str,
    ) -> BoxFuture<'a, Result<Option<ReservedJob>>>;
    fn size<'a>(&'a self, queue: &'a str) -> BoxFuture<'a, Result<u64>>;
    fn delete<'a>(&'a self, job: &'a ReservedJob) -> BoxFuture<'a, Result<()>>;
    fn release<'a>(
        &'a self,
        job: &'a ReservedJob,
        delay: Duration,
    ) -> BoxFuture<'a, Result<()>>;
    fn fail<'a>(
        &'a self,
        job: &'a ReservedJob,
        error: &'a str,
    ) -> BoxFuture<'a, Result<()>>;
    fn failed_jobs(&self) -> BoxFuture<'_, Result<Vec<FailedJob>>>;
    fn clear<'a>(&'a self, queue: &'a str) -> BoxFuture<'a, Result<u64>>;

    // Provided methods
    fn push_on<'a>(
        &'a self,
        queue: &'a str,
        job: QueuedJob,
    ) -> BoxFuture<'a, Result<String>> { ... }
    fn later<'a>(
        &'a self,
        delay: Duration,
        job: QueuedJob,
    ) -> BoxFuture<'a, Result<String>> { ... }
}

A queue backend.

Required Methods

fn driver(&self) -> &'static str

The driver’s name. It appears in queue.* events and error messages, which is how Telescope shows which backend handled a job.

fn push(&self, job: QueuedJob) -> BoxFuture<'_, Result<String>>

Store a job. Returns the driver’s identifier for it.

The envelope carries its own queue and delay, so this one primitive is all a driver has to implement.

fn pop<'a>( &'a self, queue: &'a str, ) -> BoxFuture<'a, Result<Option<ReservedJob>>>

Reserve the next available job, or None when there is nothing ready.

A delayed job whose time has not come is not “available”; neither is one another worker already holds. Reserving must be atomic across workers — see the database driver for how that is done and why.

fn size<'a>(&'a self, queue: &'a str) -> BoxFuture<'a, Result<u64>>

How many jobs are waiting on a queue, including delayed ones.

fn delete<'a>(&'a self, job: &'a ReservedJob) -> BoxFuture<'a, Result<()>>

Finish with a reserved job: it succeeded and is gone.

fn release<'a>( &'a self, job: &'a ReservedJob, delay: Duration, ) -> BoxFuture<'a, Result<()>>

Put a reserved job back, available again after delay.

The attempt count is kept, which is what makes a retry a retry rather than a fresh job that will fail forever.

fn fail<'a>( &'a self, job: &'a ReservedJob, error: &'a str, ) -> BoxFuture<'a, Result<()>>

Move a reserved job to the dead-letter store with the error that killed it. It must no longer be on the queue afterwards.

fn failed_jobs(&self) -> BoxFuture<'_, Result<Vec<FailedJob>>>

Everything in the dead-letter store, oldest first.

fn clear<'a>(&'a self, queue: &'a str) -> BoxFuture<'a, Result<u64>>

Throw away every job waiting on a queue. Returns how many went.

Provided Methods

fn push_on<'a>( &'a self, queue: &'a str, job: QueuedJob, ) -> BoxFuture<'a, Result<String>>

Store a job on a named queue, whatever the job itself asked for.

fn later<'a>( &'a self, delay: Duration, job: QueuedJob, ) -> BoxFuture<'a, Result<String>>

Store a job that only becomes visible to a worker after delay.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl Queue for DatabaseQueue

impl Queue for FakeQueue

impl Queue for MemoryQueue