alex-okrushko’s gists

alex-okrushko / IntervalBackoffConfig.ts

Last active May 23, 2018 01:58

IntervalBackoffConfig

	export interface IntervalBackoffConfig {
	initialInterval: number;
	maxInterval?: number;
	backoffDelay?: (iteration: number, initialInterval: number) => number;
	}

alex-okrushko / retry_backoff_config.ts

Last active October 2, 2018 18:24

RetryBackoffConfig used in retryBackoff - exponential backoff retry for pipeable operators


	export interface RetryBackoffConfig {
	initialInterval: number;
	maxRetries?: number;
	maxInterval?: number;
	shouldRetry?: (error: any) => boolean;
	backoffDelay?: (iteration: number, initialInterval: number) => number;
	}

alex-okrushko / app.component.ts

Created May 23, 2018 03:13

Exponential backoff retry - example with fake service

	import { Component } from '@angular/core';
	import { of } from 'rxjs';
	import { tap, switchMap} from 'rxjs/operators';
	import { retryBackoff } from 'backoff-rxjs';
	import { BackendService, HttpError } from './backend.service';

	export const INIT_INTERVAL_MS = 100; // 100 ms
	export const MAX_INTERVAL_MS = 20 * 1000; // 20 sec

	@Component({

alex-okrushko / backend.service.ts

Last active May 23, 2018 03:23

Exponential backoff retry - fake service

	import { Injectable } from '@angular/core';
	import { of, throwError, defer } from 'rxjs';

	export interface HttpError {
	error: string,
	status: string,
	}

	const ERROR_404: HttpError = { error: 'No need to try anymore', status: '404' };
	const ERROR_503: HttpError = { error: 'Try again?', status: '503' };

alex-okrushko / app.component.ts

Last active May 28, 2018 21:34

Exponential backoff retry - example with fake service

	// Determine if the error matches our expected type
	// http://www.typescriptlang.org/docs/handbook/advanced-types.html#user-defined-type-guards
	function isHttpError(error: {}): error is HttpError {
	// This is a type guard for interface
	// if HttpError was a class we would use instanceof check instead
	return (error as HttpError).status !== undefined;
	}

	message$ = of('Call me!').pipe(
	tap(console.log),

alex-okrushko / intervalBackoffUseCase.ts

Last active August 2, 2018 16:07

example of intervalBackoff that is reset on mousemove.

	import {fromEvent} from 'rxjs';
	import {sampleTime, startWith, switchMap} from 'rxjs/operators';
	import {intervalBackoff} from 'backoff-rxjs';
	import {service} from './service';

	const newData$ = fromEvent(document, 'mousemove').pipe(

	// There could be many mousemoves, we'd want to sample only
	// with certain frequency
	sampleTime(1000),

alex-okrushko / retry_backoff_simple.ts

Last active May 30, 2018 13:27

simple example of exponential backoff usage

	message$ = of('Call me!').pipe(
	switchMap(() => this.service.callBackend()),
	retryBackoff(1000),
	);

alex-okrushko / calculate_delay.ts

Created May 29, 2018 22:14

example of a function that calculated delay for each iteration in exponential backoff

	function calculateDelay(iteration, initialInterval) {
	return Math.pow(2, iteration) * initialInterval;
	}

alex-okrushko / retry_backoff_with_config.ts

Last active October 2, 2018 18:24

	message$ = of('Call me!').pipe(
	switchMap(() => this.service.callBackend()),
	retryBackoff({
	initialInterval: 100,
	maxRetries: 12,
	}),
	);

alex-okrushko / test.ts

Created October 2, 2018 01:30

	it("should handle a basic source that emits next then errors, count=3", () => {
	testScheduler.run(({ expectObservable, cold, expectSubscriptions }) => {
	const source = cold("--1-2-3-#");
	const subs = [ "^ ! ",
	" ^ ! ",
	" ^ !"
	];
	const expected = "--1-2-3----1-2-3-----1-2-3-#";

	expectObservable(

Alex Okrushko alex-okrushko