codesnips
javascript 
'use strict';

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

function backoffDelay(attempt, baseMs, maxDelayMs) {
  const exponential = baseMs * 2 ** attempt;

Retry Failed Async Operations With Exponential Backoff and Jitter in Node.js

nodejs retry backoff
by codesnips 2 tabs
java 
package com.example.observability;

public final class CorrelationIdConstants {

    public static final String HEADER_NAME = "X-Correlation-Id";
    public static final String MDC_KEY = "correlationId";

Propagate a Correlation ID Through Every Log Line with an MDC Servlet Filter in Spring Boot

spring-boot logging mdc
by codesnips 4 tabs
ruby 
require "rack/attack"
require "redis-store"

class Rack::Attack
  cache.store = Redis::Store.new(url: ENV.fetch("REDIS_URL", "redis://localhost:6379/1"))

Rate-Limiting a Sinatra JSON API With Rack::Attack Throttles and Redis

sinatra rack rack-attack
by codesnips 3 tabs
typescript 
export interface UploadHandle {
  promise: Promise<{ status: number; body: string }>;
  xhr: XMLHttpRequest;
}

export function uploadFile(

React File Upload with Live Progress Bar Using XMLHttpRequest

react file-upload xmlhttprequest
by codesnips 3 tabs
go 
package web

import (
	"embed"
	"io/fs"
)

Serve Embedded Static Assets with embed.FS and Cache Headers in Go

go embed static-assets
by codesnips 3 tabs
rust 
use std::time::Instant;

use axum::{
    extract::Request,
    http::HeaderValue,
    middleware::Next,

Axum Latency Logging Middleware With Request IDs and Tracing Spans

axum tower middleware
by codesnips 2 tabs
python 
import enum
import datetime as dt

from sqlalchemy import Column, Integer, String, BigInteger, Enum, DateTime
from sqlalchemy.orm import declarative_base

Streaming FastAPI File Uploads with a Background Validation Task

fastapi uploads background-tasks
by codesnips 3 tabs
typescript 
import React, { useMemo } from 'react';
import { VirtualList } from './VirtualList';

interface LogEntry {
  id: number;
  level: 'info' | 'warn' | 'error';

Virtualized List in React: Render Only Visible Rows on Scroll

react virtualization windowing
by codesnips 3 tabs
java 
package com.example.reference;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import jakarta.persistence.Table;

Seed Reference Data at Boot with a Spring Boot ApplicationRunner

spring-boot seeding reference-data
by codesnips 4 tabs
ruby 
class SyncContactJob < ApplicationJob
  queue_as :external

  BACKOFF = ->(executions) do
    (2**executions) + rand(0.0..1.0) # exponential + jitter, in seconds
  end

Exponential Backoff with Jitter for Flaky External API Calls in ActiveJob

rails activejob background-jobs
by codesnips 3 tabs
javascript 
import { createContext, useContext, useEffect, useMemo, useState } from 'react';
import { fetchCurrentUser, postLogin, postLogout } from './api';

const AuthContext = createContext(null);

export function AuthProvider({ children }) {

Protecting React Routes with an Auth Context and a RequireAuth Wrapper

react react-router authentication
by codesnips 4 tabs
rust 
use std::collections::HashMap;
use std::sync::Mutex;

pub type AccountId = u64;
pub type Cents = i64;

Atomic Double-Entry Ledger Transfers With Rust Locking and Poison Recovery

ledger concurrency double-entry
by codesnips 3 tabs