Code Explainers

Code explainers tagged #idempotency

javascript 
const { pool } = require('./db');
 
function withTransaction() {
  return async (req, res, next) => {

A per-request transaction middleware in Express

middleware database-transactions connection-pooling
Advanced 7 steps
javascript 
const crypto = require('crypto');
 
function idempotency({ store, ttlMs = 24 * 60 * 60 * 1000 }) {
  return async function idempotencyMiddleware(req, res, next) {

Idempotent POST requests in Express

idempotency middleware caching
Advanced 8 steps
ruby 
class ReverseGeocodeSignupJob < ApplicationJob
  queue_as :default
 
  retry_on Geocoder::OverQueryLimitError, wait: 5.minutes, attempts: 3

How Rails jobs handle reverse geocoding

background-jobs error-handling geocoding
Intermediate 7 steps
python 
import hashlib
import json
from functools import wraps
from flask import g, request, jsonify, current_app

Building an idempotency decorator in Flask

idempotency decorators redis
Advanced 7 steps
typescript 
import {
  CallHandler,
  ConflictException,
  ExecutionContext,

Idempotent POST requests in NestJS with Redis

idempotency interceptor redis
Advanced 7 steps
ruby 
class SyncInventoryJob < ApplicationJob
  queue_as :integrations
 
  retry_on Faraday::TimeoutError,

Resilient background jobs with retry_on in Rails

background-jobs error-handling retries
Intermediate 8 steps
php 
<?php
 
namespace App\Http\Controllers;
 

Processing refunds safely in Laravel

dependency injection validation database transactions
Intermediate 8 steps
java 
@Service
public class WebhookDedupService {
 
    private static final Logger log = LoggerFactory.getLogger(WebhookDedupService.class);

Idempotent webhooks with Redis in Spring

idempotency redis deduplication
Intermediate 7 steps
java 
@Component
public class IdempotencyFilter extends OncePerRequestFilter {
 
    private final StringRedisTemplate redis;

Building an idempotency filter with Redis in Spring

idempotency redis distributed-locking
Advanced 10 steps
php 
<?php
 
namespace App\Listeners;
 

Generating responsive images in a Laravel listener

queued jobs event listeners image processing
Intermediate 7 steps
php 
<?php
 
namespace App\Jobs;
 

Debouncing a Laravel shipping-rate job

queues debouncing atomic-locks
Advanced 9 steps
go 
package handlers
 
type WebhookEvent struct {
	ID   string          `json:"id"`

Verifying and processing webhooks in Gin

webhooks hmac idempotency
Intermediate 9 steps
php 
<?php
 
namespace App\Services;
 

Idempotent role assignment in Laravel

many-to-many pivot-data idempotency
Intermediate 8 steps
ruby 
module UniqueJob
  extend ActiveSupport::Concern
 
  class_methods do

Deduplicating Active Job enqueues in Rails

concurrency idempotency caching
Advanced 9 steps
go 
package middleware
 
import (
	"bytes"

Idempotent requests in Gin with Redis

idempotency caching middleware
Advanced 10 steps
php 
<?php
 
namespace App\Http\Middleware;
 

Idempotency keys in Laravel middleware

idempotency middleware caching
Advanced 8 steps
rust 
use axum::{
    extract::State,
    http::StatusCode,
    Json,

Idempotent webhook handling in Axum

deduplication idempotency shared-state
Intermediate 8 steps
python 
import json
import hashlib
from datetime import timedelta
 

Idempotent payment endpoints in FastAPI

idempotency redis distributed-locking
Advanced 9 steps