Permalink
Cannot retrieve contributors at this time
| /* | |
| * Copyright (c) 2016-2020 Martin Donath <martin.donath@squidfunk.com> | |
| * | |
| * Permission is hereby granted, free of charge, to any person obtaining a copy | |
| * of this software and associated documentation files (the "Software"), to | |
| * deal in the Software without restriction, including without limitation the | |
| * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or | |
| * sell copies of the Software, and to permit persons to whom the Software is | |
| * furnished to do so, subject to the following conditions: | |
| * | |
| * The above copyright notice and this permission notice shall be included in | |
| * all copies or substantial portions of the Software. | |
| * | |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE | |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
| * IN THE SOFTWARE. | |
| */ | |
| import { Observable, Subject, fromEvent } from "rxjs" | |
| import { | |
| map, | |
| share, | |
| switchMapTo, | |
| tap, | |
| throttle | |
| } from "rxjs/operators" | |
| /* ---------------------------------------------------------------------------- | |
| * Types | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Worker message | |
| */ | |
| export interface WorkerMessage { | |
| type: unknown /* Message type */ | |
| data?: unknown /* Message data */ | |
| } | |
| /** | |
| * Worker handler | |
| * | |
| * @template T - Message type | |
| */ | |
| export interface WorkerHandler< | |
| T extends WorkerMessage | |
| > { | |
| tx$: Subject<T> /* Message transmission subject */ | |
| rx$: Observable<T> /* Message receive observable */ | |
| } | |
| /* ---------------------------------------------------------------------------- | |
| * Helper types | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Watch options | |
| * | |
| * @template T - Worker message type | |
| */ | |
| interface WatchOptions<T extends WorkerMessage> { | |
| tx$: Observable<T> /* Message transmission observable */ | |
| } | |
| /* ---------------------------------------------------------------------------- | |
| * Functions | |
| * ------------------------------------------------------------------------- */ | |
| /** | |
| * Watch a web worker | |
| * | |
| * This function returns an observable that will send all values emitted by the | |
| * message observable to the web worker. Web worker communication is expected | |
| * to be bidirectional (request-response) and synchronous. Messages that are | |
| * emitted during a pending request are throttled, the last one is emitted. | |
| * | |
| * @param worker - Web worker | |
| * @param options - Options | |
| * | |
| * @return Worker message observable | |
| */ | |
| export function watchWorker<T extends WorkerMessage>( | |
| worker: Worker, { tx$ }: WatchOptions<T> | |
| ): Observable<T> { | |
| /* Intercept messages from worker-like objects */ | |
| const rx$ = fromEvent<MessageEvent>(worker, "message") | |
| .pipe<T>( | |
| map(({ data }) => data) | |
| ) | |
| /* Send and receive messages, return hot observable */ | |
| return tx$ | |
| .pipe( | |
| throttle(() => rx$, { leading: true, trailing: true }), | |
| tap(message => worker.postMessage(message)), | |
| switchMapTo(rx$), | |
| share() | |
| ) | |
| } |