#resource-cleanup code explainers

python

from contextlib import contextmanager
from typing import Iterator
 
import psycopg2

Streaming Postgres rows with a server-side cursor

generators context-managers database-streaming

Intermediate 7 steps

ruby

class Admin::OrdersExportController < Admin::BaseController
  include ActionController::Live
 
  def show

Streaming a CSV export in Rails

streaming csv-export batching

Advanced 8 steps

typescript

import { Injectable, Logger, OnApplicationShutdown } from '@nestjs/common';
import { InjectRedis } from '@nestjs-modules/ioredis';
import Redis from 'ioredis';
import { DataSource } from 'typeorm';

Graceful shutdown hooks in NestJS

graceful-shutdown lifecycle-hooks dependency-injection

Intermediate 7 steps

java

@RestController
@RequestMapping("/api/notifications")
public class NotificationStreamController {

Server-Sent Events per user in Spring

server-sent-events concurrency event-driven

Advanced 8 steps

python

import time
from contextlib import contextmanager

A reusable timing context manager in Python

context-manager timing generators

Intermediate 5 steps

php

<?php
 
declare(strict_types=1);

Streaming file lines with a PHP generator

generators lazy-evaluation file-io

Intermediate 7 steps

go

package main
 
import (
	"bufio"

Counting matching lines in Go with bufio

file-io buffered-scanning error-handling

Intermediate 4 steps