Struct Queue 

pub struct Queue { /* private fields */ }

A task queue.

Use of key-value store.

The queue uses a namespace handed in during creation. The first element of the scope is “pending” for pending tasks and “running” for running tasks. The second element is the Unix timestamp for when the task is scheduled in milliseconds followed by a dash and the name.

Implementations

impl Queue

pub fn create(storage_uri: &Url, namespace: &Ident) -> Result<Self, Error>

Creates a new queue.

pub fn pending_tasks_remaining(&self) -> Result<usize, Error>

Returns the number of pending tasks remaining.

pub fn running_tasks_remaining(&self) -> Result<usize, Error>

Returns the number of running tasks.

pub fn running_tasks_keys(&self) -> Result<Vec<Box<Ident>>, Error>

Returns the keys of the currently running tasks

pub fn schedule_task( &self, name: &Ident, value: &Value, timestamp_millis: Option<u128>, mode: ScheduleMode, ) -> Result<(), Error>

Schedule a new task.

The task will be scheduled to be run at the given Unix timestamp or, if the timestamp is None, immediately.

If a task with the same name already exists, then action depends on the mode.

pub fn pending_task_scheduled( &self, name: &Ident, ) -> Result<Option<u128>, Error>

Returns the scheduled timestamp in ms for the named task, if any.

pub fn finish_running_task(&self, storage_key: &Ident) -> Result<(), Error>

Marks a running task as finished.

Fails if the task is not running.

pub fn reschedule_running_task( &self, storage_key: &Ident, timestamp_millis: Option<u128>, ) -> Result<(), Error>

Reschedules a running task as pending.

Fails if the task is not running.

pub fn claim_scheduled_pending_task( &self, ) -> Result<Option<(Box<Ident>, Value)>, Error>

Claims the next scheduled pending task, if any.

pub fn reschedule_long_running_tasks( &self, reschedule_after: Option<Duration>, ) -> Result<(), Error>

Reschedules running tasks that have timed out.

Trait Implementations

impl Debug for Queue

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

Formats the value using the given formatter.