codesnips

concurrency

rust 
use std::sync::Arc;
use std::time::{Duration, Instant};
use tokio::sync::Mutex;
use tokio::time::sleep;

#[derive(Debug)]

Rate-Limiting Outbound HTTP with a Token Bucket in Rust (Tokio)

rust tokio rate-limiting
by codesnips 3 tabs
go 
package pipeline

import "context"

func generate(ctx context.Context, nums ...int) <-chan int {
	out := make(chan int)

Fan-Out/Fan-In Pipeline With Channels and Context Cancellation in Go

go concurrency channels
by codesnips 3 tabs
typescript 
import { Queue } from "bullmq";
import { createHash } from "crypto";

export const connection = { host: "127.0.0.1", port: 6379 };

export interface ChargePayload {

BullMQ job idempotency via dedupe id

node redis background-jobs
by codesnips 3 tabs
go 
package deps

import "sync"

type Lazy[T any] struct {
  once sync.Once

Lazy init of expensive clients with sync.Once

go concurrency sync
by Leah Thompson 1 tab
go 
package feed

import "time"

type Event struct {
	ID        string    `json:"id"`

Stream and Decode Newline-Delimited JSON (NDJSON) from an HTTP Response Body in Go

go ndjson streaming
by codesnips 3 tabs
java 
public class ProductAggregator implements AutoCloseable {

    private final RemoteServices services;
    private final ExecutorService pool = Executors.newFixedThreadPool(8);

    public ProductAggregator(RemoteServices services) {

Coordinate Parallel Remote Lookups With CompletableFuture in Java

java completablefuture concurrency
by codesnips 3 tabs
javascript 
const express = require('express');
const { enqueueEmail } = require('./emailQueue');

const router = express.Router();

router.post('/users/:id/welcome-email', async (req, res, next) => {

Reliable Background Email Jobs With BullMQ, Redis, and a Worker Process

bullmq redis background-jobs
by codesnips 3 tabs
sql 
CREATE TABLE idempotency_keys (
    request_key         text        NOT NULL,
    endpoint            text        NOT NULL,
    request_fingerprint text        NOT NULL,
    status              text        NOT NULL DEFAULT 'in_progress'
                                    CHECK (status IN ('in_progress', 'completed')),

Idempotency keys for “create” endpoints

reliability postgres idempotency
by codesnips 3 tabs
yaml 
name: CI

on:
  push:
    branches: [main]
  pull_request:

GitHub Actions: cache + tests + build

ci github-actions node
by codesnips 3 tabs
python 
CACHES = {
    "default": {
        "BACKEND": "django_redis.cache.RedisCache",
        "LOCATION": "redis://127.0.0.1:6379/1",
        "OPTIONS": {
            "CLIENT_CLASS": "django_redis.client.DefaultClient",

Custom DRF Throttle Class for a Public API With Sliding-Window Rate Limits

django drf rate-limiting
by codesnips 3 tabs
go 
package pool

import "context"

type Job func(ctx context.Context) error

Bounded worker pool with backpressure

go concurrency worker-pool
by Leah Thompson 1 tab
rust 
use std::sync::Arc;
use std::time::Duration;

use futures::stream::{FuturesUnordered, StreamExt};
use reqwest::Client;
use tokio::sync::Semaphore;

Bounded Concurrent HTTP Fan-Out With FuturesUnordered and Semaphore in Rust

rust async tokio
by codesnips 3 tabs