119 lines
5.2 KiB
TypeScript
119 lines
5.2 KiB
TypeScript
|
import * as a from 'node:assert';
|
||
|
|
|
||
|
|
export type TaskStatus =
|
||
|
|
| 'waitingForSettings'
|
||
|
|
| 'running'
|
||
|
|
| 'aborting:cancelled'
|
||
|
|
| 'aborting:timeout';
|
||
|
|
|
||
|
|
export type TaskStateOpts = {
|
||
|
|
taskId: string;
|
||
|
|
timeoutInS: number;
|
||
|
|
onTimeout: () => void;
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* The state of a task. The task can be in one of the following states:
|
||
|
|
* - waitingForSettings: The task is waiting for settings from the broker
|
||
|
|
* - running: The task is currently running
|
||
|
|
* - aborting:cancelled: The task was canceled by the broker and is being aborted
|
||
|
|
* - aborting:timeout: The task took too long to complete and is being aborted
|
||
|
|
*
|
||
|
|
* The task is discarded once it reaches an end state.
|
||
|
|
*
|
||
|
|
* The class only holds the state, and does not have any logic.
|
||
|
|
*
|
||
|
|
* The task has the following lifecycle:
|
||
|
|
*
|
||
|
|
* ┌───┐
|
||
|
|
* └───┘
|
||
|
|
* │
|
||
|
|
* broker:taskofferaccept : create task state
|
||
|
|
* │
|
||
|
|
* ▼
|
||
|
|
* ┌────────────────────┐ broker:taskcancel / timeout
|
||
|
|
* │ waitingForSettings ├──────────────────────────────────┐
|
||
|
|
* └────────┬───────────┘ │
|
||
|
|
* │ │
|
||
|
|
* broker:tasksettings │
|
||
|
|
* │ │
|
||
|
|
* ▼ │
|
||
|
|
* ┌───────────────┐ ┌────────────────────┐ │
|
||
|
|
* │ running │ │ aborting:timeout │ │
|
||
|
|
* │ │ timeout │ │ │
|
||
|
|
* ┌───────┤- execute task ├───────────►│- fire abort signal │ │
|
||
|
|
* │ └──────┬────────┘ └──────────┬─────────┘ │
|
||
|
|
* │ │ │ │
|
||
|
|
* │ broker:taskcancel │ │
|
||
|
|
* Task execution │ Task execution │
|
||
|
|
* resolves / rejects │ resolves / rejects │
|
||
|
|
* │ ▼ │ │
|
||
|
|
* │ ┌─────────────────────┐ │ │
|
||
|
|
* │ │ aborting:cancelled │ │ │
|
||
|
|
* │ │ │ │ │
|
||
|
|
* │ │- fire abort signal │ │ │
|
||
|
|
* │ └──────────┬──────────┘ │ │
|
||
|
|
* │ Task execution │ │
|
||
|
|
* │ resolves / rejects │ │
|
||
|
|
* │ │ │ │
|
||
|
|
* │ ▼ │ │
|
||
|
|
* │ ┌──┐ │ │
|
||
|
|
* └─────────────►│ │◄────────────────────────────┴─────────────┘
|
||
|
|
* └──┘
|
||
|
|
*/
|
||
|
|
export class TaskState {
|
||
|
|
status: TaskStatus = 'waitingForSettings';
|
||
|
|
|
||
|
|
readonly taskId: string;
|
||
|
|
|
||
|
|
/** Controller for aborting the execution of the task */
|
||
|
|
readonly abortController = new AbortController();
|
||
|
|
|
||
|
|
/** Timeout timer for the task */
|
||
|
|
private timeoutTimer: NodeJS.Timeout | undefined;
|
||
|
|
|
||
|
|
constructor(opts: TaskStateOpts) {
|
||
|
|
this.taskId = opts.taskId;
|
||
|
|
this.timeoutTimer = setTimeout(opts.onTimeout, opts.timeoutInS * 1000);
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Cleans up any resources before the task can be removed */
|
||
|
|
cleanup() {
|
||
|
|
clearTimeout(this.timeoutTimer);
|
||
|
|
this.timeoutTimer = undefined;
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Custom JSON serialization for the task state for logging purposes */
|
||
|
|
toJSON() {
|
||
|
|
return `[Task ${this.taskId} (${this.status})]`;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Executes the function matching the current task status
|
||
|
|
*
|
||
|
|
* @example
|
||
|
|
* ```ts
|
||
|
|
* taskState.caseOf({
|
||
|
|
* waitingForSettings: () => {...},
|
||
|
|
* running: () => {...},
|
||
|
|
* aborting:cancelled: () => {...},
|
||
|
|
* aborting:timeout: () => {...},
|
||
|
|
* });
|
||
|
|
* ```
|
||
|
|
*/
|
||
|
|
async caseOf(
|
||
|
|
conditions: Record<TaskStatus, (taskState: TaskState) => void | Promise<void> | never>,
|
||
|
|
) {
|
||
|
|
if (!conditions[this.status]) {
|
||
|
|
TaskState.throwUnexpectedTaskStatus(this);
|
||
|
|
}
|
||
|
|
|
||
|
|
return await conditions[this.status](this);
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Throws an error that the task status is unexpected */
|
||
|
|
static throwUnexpectedTaskStatus = (taskState: TaskState) => {
|
||
|
|
a.fail(`Unexpected task status: ${JSON.stringify(taskState)}`);
|
||
|
|
};
|
||
|
|
}
|