62 lines
2.5 KiB
JavaScript
62 lines
2.5 KiB
JavaScript
import { Observable } from '../Observable';
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import { argsArgArrayOrObject } from '../util/argsArgArrayOrObject';
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import { from } from './from';
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import { identity } from '../util/identity';
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import { mapOneOrManyArgs } from '../util/mapOneOrManyArgs';
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import { popResultSelector, popScheduler } from '../util/args';
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import { createObject } from '../util/createObject';
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import { createOperatorSubscriber } from '../operators/OperatorSubscriber';
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import { executeSchedule } from '../util/executeSchedule';
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export function combineLatest(...args) {
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const scheduler = popScheduler(args);
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const resultSelector = popResultSelector(args);
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const { args: observables, keys } = argsArgArrayOrObject(args);
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if (observables.length === 0) {
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return from([], scheduler);
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}
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const result = new Observable(combineLatestInit(observables, scheduler, keys
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?
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(values) => createObject(keys, values)
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:
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identity));
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return resultSelector ? result.pipe(mapOneOrManyArgs(resultSelector)) : result;
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}
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export function combineLatestInit(observables, scheduler, valueTransform = identity) {
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return (subscriber) => {
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maybeSchedule(scheduler, () => {
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const { length } = observables;
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const values = new Array(length);
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let active = length;
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let remainingFirstValues = length;
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for (let i = 0; i < length; i++) {
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maybeSchedule(scheduler, () => {
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const source = from(observables[i], scheduler);
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let hasFirstValue = false;
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source.subscribe(createOperatorSubscriber(subscriber, (value) => {
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values[i] = value;
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if (!hasFirstValue) {
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hasFirstValue = true;
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remainingFirstValues--;
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}
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if (!remainingFirstValues) {
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subscriber.next(valueTransform(values.slice()));
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}
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}, () => {
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if (!--active) {
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subscriber.complete();
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}
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}));
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}, subscriber);
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}
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}, subscriber);
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};
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}
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function maybeSchedule(scheduler, execute, subscription) {
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if (scheduler) {
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executeSchedule(subscription, scheduler, execute);
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}
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else {
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execute();
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}
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}
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//# sourceMappingURL=combineLatest.js.map
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