codesnips
python 
from typing import Optional
from pydantic import BaseModel, EmailStr, Field, field_validator, model_validator


class CreateUserRequest(BaseModel):
    model_config = {"extra": "forbid"}

Validating JSON Payloads with Pydantic v2 and Returning Field-Level Errors in FastAPI

fastapi pydantic validation
by codesnips 3 tabs
java 
package com.example.orders;

public final class Order {

    public static final Order POISON_PILL = new Order(-1L, 0.0);

Producer/Consumer Order Processing With a Bounded BlockingQueue in Java

java concurrency blockingqueue
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
lua 
-- KEYS[1] = current window key, KEYS[2] = previous window key
-- ARGV: limit, window_ms, elapsed_ms
local limit = tonumber(ARGV[1])
local window = tonumber(ARGV[2])
local elapsed = tonumber(ARGV[3])

Sliding-Window Rate Limiting for Express Routes Backed by Redis

express redis rate-limiting
by codesnips 4 tabs
php 
<?php

namespace App\Exports;

use Illuminate\Database\Eloquent\Builder;
use Illuminate\Support\Carbon;

Streaming a Filtered Orders CSV Export in Laravel with StreamedResponse

php laravel csv
by codesnips 3 tabs
python 
from abc import ABC, abstractmethod


class UnknownChannel(Exception):
    pass

Pluggable Notification Channels With a Template Registry in Python

notifications design-patterns strategy-pattern
by codesnips 3 tabs
rust 
use std::sync::mpsc::{self, SyncSender};
use std::sync::{Arc, Mutex};
use std::thread;

mod worker;
use worker::{Message, Worker};

Bounded Thread Pool With Backpressure Using Rust Channels

threads concurrency channels
by codesnips 3 tabs
python 
import asyncio
import time
from dataclasses import dataclass, field


@dataclass

Per-Client Rate Limiting in FastAPI with a Token Bucket Dependency

python fastapi rate-limiting
by codesnips 3 tabs
java 
package com.example.users.domain;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;

Mapping JPA Entities to DTOs with a MapStruct Mapper Injected into a Spring Service

spring-boot mapstruct dto
by codesnips 4 tabs
python 
import base64
import json
from datetime import datetime
from typing import Optional, Tuple

Opaque Cursor Pagination for FastAPI Endpoints with SQLAlchemy

fastapi sqlalchemy pagination
by codesnips 3 tabs
javascript 
import { useCallback, useEffect, useState } from 'react';

function parseSearch(search) {
  const params = new URLSearchParams(search);
  const out = {};
  for (const [key, value] of params.entries()) out[key] = value;

Sync React Form State to the URL Query String with a Debounced useSearchParams Hook

react hooks url-state
by codesnips 3 tabs
javascript 
import { useCallback, useEffect, useRef, useState } from 'react';

export function usePaginatedFetch(fetchPage, { pageSize = 20 } = {}) {
  const [items, setItems] = useState([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState(null);

Infinite Scroll in React with IntersectionObserver and a Paginated Fetch Hook

react hooks infinite-scroll
by codesnips 3 tabs