import { QueueAction } from './QueueAction';
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import { QueueScheduler } from './QueueScheduler';
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/**
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*
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* Queue Scheduler
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*
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* <span class="informal">Put every next task on a queue, instead of executing it immediately</span>
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*
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* `queue` scheduler, when used with delay, behaves the same as {@link asyncScheduler} scheduler.
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*
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* When used without delay, it schedules given task synchronously - executes it right when
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* it is scheduled. However when called recursively, that is when inside the scheduled task,
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* another task is scheduled with queue scheduler, instead of executing immediately as well,
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* that task will be put on a queue and wait for current one to finish.
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*
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* This means that when you execute task with `queue` scheduler, you are sure it will end
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* before any other task scheduled with that scheduler will start.
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*
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* ## Examples
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* Schedule recursively first, then do something
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* ```ts
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* import { queueScheduler } from 'rxjs';
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*
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* queueScheduler.schedule(() => {
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* queueScheduler.schedule(() => console.log('second')); // will not happen now, but will be put on a queue
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*
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* console.log('first');
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* });
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*
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* // Logs:
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* // "first"
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* // "second"
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* ```
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*
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* Reschedule itself recursively
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* ```ts
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* import { queueScheduler } from 'rxjs';
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*
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* queueScheduler.schedule(function(state) {
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* if (state !== 0) {
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* console.log('before', state);
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* this.schedule(state - 1); // `this` references currently executing Action,
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* // which we reschedule with new state
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* console.log('after', state);
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* }
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* }, 0, 3);
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*
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* // In scheduler that runs recursively, you would expect:
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* // "before", 3
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* // "before", 2
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* // "before", 1
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* // "after", 1
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* // "after", 2
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* // "after", 3
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*
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* // But with queue it logs:
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* // "before", 3
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* // "after", 3
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* // "before", 2
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* // "after", 2
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* // "before", 1
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* // "after", 1
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* ```
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*/
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export const queueScheduler = new QueueScheduler(QueueAction);
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/**
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* @deprecated Renamed to {@link queueScheduler}. Will be removed in v8.
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*/
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export const queue = queueScheduler;
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