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- import { MonoTypeOperatorFunction, ObservableInput } from '../types';
- import { operate } from '../util/lift';
- import { Subscription } from '../Subscription';
- import { createOperatorSubscriber } from './OperatorSubscriber';
- import { identity } from '../util/identity';
- import { timer } from '../observable/timer';
- import { innerFrom } from '../observable/innerFrom';
- /**
- * The {@link retry} operator configuration object. `retry` either accepts a `number`
- * or an object described by this interface.
- */
- export interface RetryConfig {
- /**
- * The maximum number of times to retry. If `count` is omitted, `retry` will try to
- * resubscribe on errors infinite number of times.
- */
- count?: number;
- /**
- * The number of milliseconds to delay before retrying, OR a function to
- * return a notifier for delaying. If a function is given, that function should
- * return a notifier that, when it emits will retry the source. If the notifier
- * completes _without_ emitting, the resulting observable will complete without error,
- * if the notifier errors, the error will be pushed to the result.
- */
- delay?: number | ((error: any, retryCount: number) => ObservableInput<any>);
- /**
- * Whether or not to reset the retry counter when the retried subscription
- * emits its first value.
- */
- resetOnSuccess?: boolean;
- }
- export function retry<T>(count?: number): MonoTypeOperatorFunction<T>;
- export function retry<T>(config: RetryConfig): MonoTypeOperatorFunction<T>;
- /**
- * Returns an Observable that mirrors the source Observable with the exception of an `error`.
- *
- * If the source Observable calls `error`, this method will resubscribe to the source Observable for a maximum of
- * `count` resubscriptions rather than propagating the `error` call.
- *
- * 
- *
- * The number of retries is determined by the `count` parameter. It can be set either by passing a number to
- * `retry` function or by setting `count` property when `retry` is configured using {@link RetryConfig}. If
- * `count` is omitted, `retry` will try to resubscribe on errors infinite number of times.
- *
- * Any and all items emitted by the source Observable will be emitted by the resulting Observable, even those
- * emitted during failed subscriptions. For example, if an Observable fails at first but emits `[1, 2]` then
- * succeeds the second time and emits: `[1, 2, 3, 4, 5, complete]` then the complete stream of emissions and
- * notifications would be: `[1, 2, 1, 2, 3, 4, 5, complete]`.
- *
- * ## Example
- *
- * ```ts
- * import { interval, mergeMap, throwError, of, retry } from 'rxjs';
- *
- * const source = interval(1000);
- * const result = source.pipe(
- * mergeMap(val => val > 5 ? throwError(() => 'Error!') : of(val)),
- * retry(2) // retry 2 times on error
- * );
- *
- * result.subscribe({
- * next: value => console.log(value),
- * error: err => console.log(`${ err }: Retried 2 times then quit!`)
- * });
- *
- * // Output:
- * // 0..1..2..3..4..5..
- * // 0..1..2..3..4..5..
- * // 0..1..2..3..4..5..
- * // 'Error!: Retried 2 times then quit!'
- * ```
- *
- * @see {@link retryWhen}
- *
- * @param configOrCount Either number of retry attempts before failing or a
- * {@link RetryConfig} object.
- * @return A function that returns an Observable that will resubscribe to the
- * source stream when the source stream errors, at most `count` times.
- */
- export function retry<T>(configOrCount: number | RetryConfig = Infinity): MonoTypeOperatorFunction<T> {
- let config: RetryConfig;
- if (configOrCount && typeof configOrCount === 'object') {
- config = configOrCount;
- } else {
- config = {
- count: configOrCount as number,
- };
- }
- const { count = Infinity, delay, resetOnSuccess: resetOnSuccess = false } = config;
- return count <= 0
- ? identity
- : operate((source, subscriber) => {
- let soFar = 0;
- let innerSub: Subscription | null;
- const subscribeForRetry = () => {
- let syncUnsub = false;
- innerSub = source.subscribe(
- createOperatorSubscriber(
- subscriber,
- (value) => {
- // If we're resetting on success
- if (resetOnSuccess) {
- soFar = 0;
- }
- subscriber.next(value);
- },
- // Completions are passed through to consumer.
- undefined,
- (err) => {
- if (soFar++ < count) {
- // We are still under our retry count
- const resub = () => {
- if (innerSub) {
- innerSub.unsubscribe();
- innerSub = null;
- subscribeForRetry();
- } else {
- syncUnsub = true;
- }
- };
- if (delay != null) {
- // The user specified a retry delay.
- // They gave us a number, use a timer, otherwise, it's a function,
- // and we're going to call it to get a notifier.
- const notifier = typeof delay === 'number' ? timer(delay) : innerFrom(delay(err, soFar));
- const notifierSubscriber = createOperatorSubscriber(
- subscriber,
- () => {
- // After we get the first notification, we
- // unsubscribe from the notifier, because we don't want anymore
- // and we resubscribe to the source.
- notifierSubscriber.unsubscribe();
- resub();
- },
- () => {
- // The notifier completed without emitting.
- // The author is telling us they want to complete.
- subscriber.complete();
- }
- );
- notifier.subscribe(notifierSubscriber);
- } else {
- // There was no notifier given. Just resub immediately.
- resub();
- }
- } else {
- // We're past our maximum number of retries.
- // Just send along the error.
- subscriber.error(err);
- }
- }
- )
- );
- if (syncUnsub) {
- innerSub.unsubscribe();
- innerSub = null;
- subscribeForRetry();
- }
- };
- subscribeForRetry();
- });
- }
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