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// Chi-like syntactic sugar layer on top of stdlib http.ServeMux.
package main

import (
	"net/http"
	"slices"
)

type (
	middleware func(http.Handler) http.Handler

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Scaling your API with rate limiters

The following are examples of the four types rate limiters discussed in the accompanying blog post. In the examples below I've used pseudocode-like Ruby, so if you're unfamiliar with Ruby you should be able to easily translate this approach to other languages. Complete examples in Ruby are also provided later in this gist.

In most cases you'll want all these examples to be classes, but I've used simple functions here to keep the code samples brief.

Request rate limiter

This uses a basic token bucket algorithm and relies on the fact that Redis scripts execute atomically. No other operations can run between fetching the count and writing the new count.

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-- gets all fields from a hash as a dictionary
local hgetall = function (key)
  local bulk = redis.call('HGETALL', key)
	local result = {}
	local nextkey
	for i, v in ipairs(bulk) do
		if i % 2 == 1 then
			nextkey = v
		else
			result[nextkey] = v

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Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

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# Copyright (c) 2014 Andrey Vlasovskikh
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in

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// Example
package main;

import (
    "jsonhelper"
    "fmt"
)

func main(){
	jsonValue := []interface {}{

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#
# Slightly tighter CORS config for nginx
#
# A modification of https://gist.github.com/1064640/ to include a white-list of URLs
#
# Despite the W3C guidance suggesting that a list of origins can be passed as part of
# Access-Control-Allow-Origin headers, several browsers (well, at least Firefox) 
# don't seem to play nicely with this.
#

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// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

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#!/usr/bin/env python
# encoding: utf-8
import functools
import hashlib
import logging

import tornado.web
import tornado.gen
import tornado.httpclient
import tornado.ioloop