gaffer

Prioritised, parallel job scheduler with concurrent exclusion, job merging, recurring jobs and load limiting for lower priorities.

A job scheduler executes tasks on it's own thread or thread pool. This job scheduler is particularly designed to consider heavier weight or more expensive jobs, which likely have side effects. In this case it can be valuable to prioritise the jobs and merge alike jobs in the queue.

Features

Recurring jobs: jobs which will be re-enqueued at some interval ²
Job queue: use an crossbeam_channel::Sender<YourJob> to send jobs
Future Jobs: (Optionally) create Futures to get results from the jobs ²
Job prioritisation: provide a priority for jobs and all the jobs will be executed in that order
Job merging: merge identical / similar jobs in the queue to reduce workload ²
Parallel execution: run jobs on multiple threads and lock jobs which should be run exclusively, they remain in the queue and don't occupy other resources
Priority throttling: in order to have idle threads ready to pick up higher-priority jobs, throttle lower priority jobs by restricting them to a lower number of threads

Limitations

² There are a few ergonomics issues to do with the job merging and recurring jobs apis. For example, all jobs need to implement Clone (so they can be reproduced for recurring) and any results provided by a future need to implement Clone (so that they can be merged).
some of the tests are very dependent on timing and will fail if run slowly

Usage

With cargo-edit:

sh cargo add gaffer

or in Cargo.toml

toml [dependencies] gaffer = "0.1"

License

Licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.