@itwin/presentation-hierarchies
Version:
A package for creating hierarchies based on data in iTwin.js iModels.
57 lines • 2.69 kB
JavaScript
;
/*---------------------------------------------------------------------------------------------
* Copyright (c) Bentley Systems, Incorporated. All rights reserved.
* See LICENSE.md in the project root for license terms and full copyright notice.
*--------------------------------------------------------------------------------------------*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.SubscriptionScheduler = void 0;
const rxjs_1 = require("rxjs");
/** @internal */
class SubscriptionScheduler {
_scheduler = new rxjs_1.Subject();
constructor(concurrency) {
this._scheduler
.pipe((0, rxjs_1.mergeMap)((sourceObservable) => {
return sourceObservable.pipe(
// connect source observable when scheduler subscribes
(0, rxjs_1.tap)({
subscribe: () => {
sourceObservable.connect();
},
}),
// Guard against stack overflow when a lot of observables are scheduled. Without this operation `mergeMap`
// will process each observable that is present in the pipeline recursively.
(0, rxjs_1.observeOn)(rxjs_1.queueScheduler),
// Delay the connection until another event loop task
(0, rxjs_1.subscribeOn)(rxjs_1.asapScheduler),
// Ignore errors in this pipeline without suppressing them for other subscribers
(0, rxjs_1.onErrorResumeNextWith)());
}, concurrency))
// Start consuming scheduled observables
.subscribe();
}
/**
* Schedules `source` for subscription in the current scheduler.
*
* The actual scheduling is performed when the returned observable is subscribed to. To cancel, remove all subscribers
* from the returned observable.
*
* @param source Input observable for which to schedule a subscription.
* @returns Hot observable which starts emitting `source` values after subscription.
*/
scheduleSubscription(source) {
return (0, rxjs_1.defer)(() => {
let unsubscribed = false;
const connectableObservable = (0, rxjs_1.connectable)((0, rxjs_1.iif)(() => unsubscribed, rxjs_1.EMPTY, source), {
connector: () => new rxjs_1.Subject(),
resetOnDisconnect: false,
});
this._scheduler.next(connectableObservable);
return connectableObservable.pipe((0, rxjs_1.finalize)(() => {
unsubscribed = true;
}));
});
}
}
exports.SubscriptionScheduler = SubscriptionScheduler;
//# sourceMappingURL=SubscriptionScheduler.js.map