codesnips

caching

ruby 
class LastSeenTracker
  THROTTLE = 5.minutes
  PENDING_KEY = "pending:last_seen".freeze

  class << self
    def touch(user_id, at: Time.current)

Database “Last Seen” without Hot Row Updates

rails performance redis
by codesnips 3 tabs
ruby 
module RequestStore
  def self.store
    Thread.current[:request_store] ||= {}
  end

  def self.fetch(key)

Hot Path Memoization (within request only)

rails performance memoization
by codesnips 4 tabs
go 
package api

import "net/http"

func ETag(w http.ResponseWriter, r *http.Request, etag string) bool {
  w.Header().Set("ETag", etag)

ETag handling for conditional GETs (cheap caching)

go http caching
by Leah Thompson 1 tab
go 
package pricecache

import (
	"context"
	"sync"

Collapse Concurrent Identical Requests in Go with singleflight

go singleflight concurrency
by codesnips 3 tabs
javascript 
class BatchLoader {
  constructor(batchFn, { cacheKeyFn = (k) => k } = {}) {
    this.batchFn = batchFn;
    this.cacheKeyFn = cacheKeyFn;
    this.cache = new Map();
    this.queue = [];

Coalescing Concurrent Reads with a DataLoader-Style Batch Loader in Node

dataloader batching graphql
by codesnips 3 tabs
python 
import functools
import threading
import time
from collections import OrderedDict

Custom TTL + LRU Cache Decorator for Expensive Python Computations

python caching lru
by codesnips 2 tabs