wisp-task

This module contains code to assist with running tasks.

RepeatedTask runs a repeated task at the user controlled rate based on the kotlin-retry library. For convenience a RepeatedTaskManager is available to help manage the RepeatedTasks.

It’s possible to specify your own retry policy for the task. See kotlin-retry library for more details and examples. The default retry policy instructions are to retry on all exceptions with a Binary Exponential backoff delay - which itself is configured from the supplied RepeatedTaskConfig .

Usage

Create a repeated task and start it running.

val repeatedTaskConfig = RepeatedTaskConfig(
  timeBetweenRunsMs = 10000L  // 10 sec delay between task runs or retries
)

val manager = RepeatedTaskManager()

val newTask = manager.createTask(
  name = "taskName",
  repeatedTaskConfig = repeatedTaskConfig,
) { name: String, taskConfig: TaskConfig ->
  // do task stuff
  // ...

  // if the task completes correctly, return OK.
  Status.OK
}

newTask.startUp()

You can shutdown a task or the manager which will shutdown all tasks. Using the above code:

// shut down the repeated task.
newTask.shutDown()

// shut down all repeated tasks known by the manager.
manager.shutDown()

The task to be run takes a TaskConfig (which could be loaded using wisp-config).

class MyTaskConfig(
  val foo: String,
  val allResults: MutableList<String> = mutableListOf()
): TaskConfig()

val taskName = "myTask"
val anotherTask = manager.createTask(
  name = taskName,
  repeatedTaskConfig = repeatedTaskConfig,
  taskConfig = MyTaskConfig("fooString")
) { name: String, taskConfig: TaskConfig ->
  val config = taskConfig as MyTaskConfig

  // access the taskConfig
  println("Foo is ${config.foo}")

  // do task stuff
  // ...
  config.allResults.add("another result")

  // if the task completes correctly, return OK.
  Status.OK
}