codesnips
rust 
use std::collections::VecDeque;

pub struct RollingAverage {
    buf: VecDeque<f64>,
    capacity: usize,
    sum: f64,

Rolling Average Over a Sliding Window of Sensor Readings in Rust

rust sliding-window streaming
by codesnips 2 tabs
rust 
#[derive(Debug, Clone)]
pub struct Order {
    pub id: u64,
    pub amount_cents: i64,
    pub currency: [u8; 3],
}

Partition a Slice of Orders into Shards for Parallel Processing with Rayon

rust rayon parallelism
by codesnips 2 tabs
rust 
use std::time::{Duration, Instant};

pub struct LeakyBucket {
    level: f64,
    capacity: f64,
    rate_per_sec: f64,

Leaky-Bucket Rate Shaper for a Tokio Message Consumer

rate-limiting leaky-bucket backpressure
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
python 
import contextvars
import uuid

_correlation_id: contextvars.ContextVar[str] = contextvars.ContextVar(
    "correlation_id", default="-"
)

Propagating a Correlation ID Through contextvars in FastAPI

fastapi contextvars middleware
by codesnips 4 tabs
typescript 
import { AbstractControl, ValidationErrors, ValidatorFn } from '@angular/forms';

function hasActualValue(control: AbstractControl | null): boolean {
  return !!control && control.value !== null && control.value !== '';
}

Cross-Field Password-Confirmation Validator for Angular Reactive Forms

angular reactive-forms validators
by codesnips 3 tabs
javascript 
class DeadlineError extends Error {
  constructor(message = 'request deadline exceeded') {
    super(message);
    this.name = 'DeadlineError';
    this.code = 'DEADLINE_EXCEEDED';
  }

Enforce Per-Request Timeouts by Aborting Downstream Fetches with AbortSignal

node fetch abortcontroller
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
sql 
CREATE TABLE idempotency_keys (
    id              BIGSERIAL PRIMARY KEY,
    idempotency_key TEXT        NOT NULL,
    request_path    TEXT        NOT NULL,
    request_fingerprint TEXT    NOT NULL,
    status          TEXT        NOT NULL DEFAULT 'in_progress',

Idempotent POST Requests with an Idempotency-Key Middleware in Express

express idempotency middleware
by codesnips 3 tabs
rust 
use serde::{Deserialize, Serialize};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AppConfig {
    #[serde(default)]
    pub server: ServerConfig,

Layered Config Loading From TOML File and Environment Variables in Rust

config serde toml
by codesnips 3 tabs