codesnips

background-jobs

python 
import queue
import time
from dataclasses import dataclass, field, replace
from typing import Any, Dict, Tuple

In-Process Threaded Background Job Queue for Sending Emails Without Redis

background-jobs threading queue
by codesnips 4 tabs
ruby 
class ShippedEmailJob
  include Sidekiq::Job
  sidekiq_options queue: :mailers, retry: 5

  def perform(order_id)
    order = Order.find_by(id: order_id)

Fan Out Notifications to Email and SMS Using an ActiveRecord Observer

rails activerecord observer
by codesnips 3 tabs
sql 
CREATE TYPE outbox_status AS ENUM ('pending', 'retry', 'processing', 'done', 'dead');

CREATE TABLE outbox_events (
    id           BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
    dedupe_key   TEXT        NOT NULL,
    topic        TEXT        NOT NULL,

Atomic “Read + Mark Processed” with UPDATE … RETURNING

postgres concurrency reliability
by codesnips 3 tabs
ruby 
class CounterBuffer
  DELTA_HASH = "counter:deltas".freeze

  READ_RESET = <<~LUA.freeze
    local v = redis.call('HGET', KEYS[1], ARGV[1])
    if v then redis.call('HDEL', KEYS[1], ARGV[1]) end

Debounce Expensive Counter Cache Updates with a Throttled Redis Buffer in Rails

rails redis counter-cache
by codesnips 3 tabs
ruby 
class ImportRun < ApplicationRecord
  enum status: { pending: 0, running: 1, completed: 2, failed: 3 }

  def percent
    return 0 if total.to_i.zero?
    [(processed.to_f / total * 100).round, 100].min

Live Turbo Streams Progress Bar for a Long Rails Job

rails turbo-streams hotwire
by codesnips 4 tabs
ruby 
namespace :cleanup do
  desc "Enqueue a job to purge expired sessions"
  task expired_sessions: :environment do
    job = ExpiredSessionCleanupJob.perform_later
    Rails.logger.info("[cleanup:expired_sessions] enqueued job #{job.job_id}")
  end

Recurring Cleanup with a Rake Task and an Idempotent Active Job in Rails

rails background-jobs active-job
by codesnips 4 tabs
python 
import asyncio
import uuid
from dataclasses import dataclass, field
from typing import Any, Dict, Optional

Long-Polling a Background Job's Status with a Shared Result Registry in FastAPI

fastapi asyncio long-polling
by codesnips 3 tabs
typescript 
export interface CronFields {
  minute: Set<number>;
  hour: Set<number>;
  dayOfMonth: Set<number>;
  month: Set<number>;
  dayOfWeek: Set<number>;

Cron-Expression Scheduler with Field Parser and a Tick Loop in TypeScript

cron scheduler parser
by codesnips 3 tabs
ruby 
require "securerandom"

class RedisMutex
  class LockError < StandardError; end

  UNLOCK_SCRIPT = <<~LUA.freeze

Redis-Based Distributed Mutex (with TTL)

rails redis concurrency
by codesnips 2 tabs
php 
<?php

namespace App\Http\Controllers\Auth;

use App\Events\UserRegistered;
use App\Http\Controllers\Controller;

Dispatch a Queued Welcome Email via Laravel Event Listeners on Registration

laravel events listeners
by codesnips 4 tabs
ruby 
class ExportWriter
  def initialize(export)
    @export = export
  end

  def append(rows)

Chaining Dependent GoodJob Jobs with a Callback-Scheduled Continuation

rails good-job background-jobs
by codesnips 3 tabs
php 
<?php

namespace App\Jobs;

use App\Models\Invoice;
use App\Services\StripeGateway;

Preventing Double-Charges in Laravel with WithoutOverlapping Job Middleware

laravel queues background-jobs
by codesnips 3 tabs