SubscriptionImpl.ts
57 lines
| 1.3 KiB
| video/mp2t
|
TypeScriptLexer
cin
|
r158 | import { ICancellation } from "@implab/core-amd/interfaces"; | |
| export interface Subscription { | |||
| finalize(): boolean; | |||
| isClosed(): boolean; | |||
| teardown(cleanup: void | (() => void)): void; | |||
| around<T>(next: (item: T) => void): (item: T) => void; | |||
| unsubscribe(): void; | |||
| } | |||
| const noop = () => {}; | |||
| export class SubscriptionImpl implements Subscription { | |||
| private _done = false; | |||
| private _cleanup = noop; | |||
| finalize() { | |||
| return this._done ? false : ((0,this._cleanup)(), this._done = true); | |||
| } | |||
| isClosed() { | |||
| return this._done; | |||
| } | |||
| teardown(cleanup: void | (() => void)) { | |||
| if (cleanup) { | |||
| if (this._done) { | |||
| cleanup(); | |||
| } else { | |||
| const _prev = this._cleanup; | |||
| this._cleanup = _prev === noop ? cleanup : () => (_prev(), cleanup()); | |||
| } | |||
| } | |||
| } | |||
| cancellable(ct: ICancellation, reject: (err: unknown) => void) { | |||
| if (ct.isSupported()) { | |||
| const h = ct.register(reason => this.finalize() && reject(reason)); | |||
| this.teardown(() => h.destroy()); | |||
| } | |||
| } | |||
| unsubscribe() { | |||
| this.finalize(); | |||
| } | |||
| around<T>(next: (item: T) => void): (item: T) => void { | |||
| return (item) => this._done ? void(0) : next(item); | |||
| } | |||
| } |