forked from mystiq/hydrogen-web
135 lines
4 KiB
TypeScript
135 lines
4 KiB
TypeScript
/*
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Copyright 2020 Bruno Windels <bruno@windels.cloud>
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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import {AbortError} from "../../utils/error";
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import type {Timeout} from "../../platform/web/dom/Clock.js";
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type TimeoutCreator = (ms: number) => Timeout;
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const enum Default { start = 2000 }
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export class ExponentialRetryDelay {
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private readonly _start: number = Default.start;
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private _current: number = Default.start;
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private readonly _createTimeout: TimeoutCreator;
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private readonly _max: number;
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private _timeout?: Timeout;
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constructor(createTimeout: TimeoutCreator) {
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const start = 2000;
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this._start = start;
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this._current = start;
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this._createTimeout = createTimeout;
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this._max = 60 * 5 * 1000; //5 min
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}
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async waitForRetry(): Promise<void> {
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this._timeout = this._createTimeout(this._current);
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try {
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await this._timeout.elapsed();
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// only increase delay if we didn't get interrupted
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const next = 2 * this._current;
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this._current = Math.min(this._max, next);
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} catch(err) {
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// swallow AbortError, means abort was called
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if (!(err instanceof AbortError)) {
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throw err;
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}
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} finally {
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this._timeout = undefined;
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}
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}
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abort(): void {
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if (this._timeout) {
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this._timeout.abort();
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}
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}
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reset(): void {
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this._current = this._start;
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this.abort();
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}
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get nextValue(): number {
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return this._current;
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}
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}
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import {Clock as MockClock} from "../../mocks/Clock.js";
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export function tests() {
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return {
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"test sequence": async assert => {
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const clock = new MockClock();
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const retryDelay = new ExponentialRetryDelay(clock.createTimeout);
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let promise;
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assert.strictEqual(retryDelay.nextValue, 2000);
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promise = retryDelay.waitForRetry();
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clock.elapse(2000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 4000);
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promise = retryDelay.waitForRetry();
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clock.elapse(4000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 8000);
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promise = retryDelay.waitForRetry();
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clock.elapse(8000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 16000);
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promise = retryDelay.waitForRetry();
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clock.elapse(16000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 32000);
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promise = retryDelay.waitForRetry();
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clock.elapse(32000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 64000);
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promise = retryDelay.waitForRetry();
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clock.elapse(64000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 128000);
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promise = retryDelay.waitForRetry();
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clock.elapse(128000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 256000);
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promise = retryDelay.waitForRetry();
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clock.elapse(256000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 300000);
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promise = retryDelay.waitForRetry();
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clock.elapse(300000);
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await promise;
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assert.strictEqual(retryDelay.nextValue, 300000);
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promise = retryDelay.waitForRetry();
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clock.elapse(300000);
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await promise;
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},
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}
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}
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