DanielGibson

/*
 * Try to find out the libstdc++.so.6 version on the (x86 or x86_64) Linux
 * system this is executed on.
 * (you could then use that information to decide whether to use LD_PRELOAD
 *  or LD_LIBRARY_PATH to make a C++ program launched from here use a newer
 *  version of libstdc++.so.6 that you provide)
 * 
 * (C) 2017 Daniel Gibson
 * 
 * LICENSE

ptarjan

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.

djspiewak

Getting Started in Scala

This is my attempt to give Scala newcomers a quick-and-easy rundown to the prerequisite steps they need to a) try Scala, and b) get a standard project up and running on their machine. I'm not going to talk about the language at all; there are plenty of better resources a google search away. This is just focused on the prerequisite tooling and machine setup. I will not be assuming you have any background in JVM languages. So if you're coming from Python, Ruby, JavaScript, Haskell, or anywhere…  I hope to present the information you need without assuming anything.

Disclaimer It has been over a decade since I was new to Scala, and when I was new to Scala, I was coming from a Java and Ruby background. This has probably caused me to unknowingly make some assumptions. Please feel free to call me out in comments/tweets!

One assumption I'm knowingly making is that you're on a Unix-like platform. Sorry, Windows users.

Getting the JVM

mahmoud

"""
This is an extension of the technique first detailed here:

http://sedimental.org/remap.html#add_common_keys

In short, it calls remap on each container, back to front, using the accumulating
previous values as the default for the current iteration.
"""

cwest

#!/usr/bin/env bash
set -ex

#   ____ _                 _ _____                     _              __  ____     ______  
#  / ___| | ___  _   _  __| |  ___|__  _   _ _ __   __| |_ __ _   _  |  \/  \ \   / /  _ \ 
# | |   | |/ _ \| | | |/ _` | |_ / _ \| | | | '_ \ / _` | '__| | | | | |\/| |\ \ / /| |_) |
# | |___| | (_) | |_| | (_| |  _| (_) | |_| | | | | (_| | |  | |_| | | |  | | \ V / |  __/ 
#  \____|_|\___/ \__,_|\__,_|_|  \___/ \__,_|_| |_|\__,_|_|   \__, | |_|  |_|  \_/  |_|    
#                                                             |___/                        

dwijnand

+-----------------------------------------------------------------------------------------------------+
|  name   |  bits  | bytes  |  min  | actual min value           |  max   | actual max value          |
|---------+--------+--------+-------+----------------------------+--------+---------------------------|
| boolean |  1-bit |   --   | false |                            | true   |                           |
| byte    |  8-bit | 1-byte | -2^7  | -128                       | 2^7-1  | 127                       |
| short   | 16-bit | 2-byte | -2^15 | -32'768                    | 2^15-1 | 32'767                    |
| char    | 16-bit | 2-byte | 0     | '\u0000'                   | 2^16-1 | '\uffff'  (65535)         |
| int     | 32-bit | 4-byte | -2^31 | -2'147'483'648             | 2^31-1 | 2'147'483'647             |
| long    | 64-bit | 8-byte | -2^63 | -9'223'372'036'854'775'808 | 2^63-1 | 9'223'372'036'854'775'807 |
| float   | 32-bit | 4-byte | +/- -3.4028235 * 10^38             | +/- 3.4028235 * 10^38

reklis

/*
	Reliability and Flow Control Example
	From "Networking for Game Programmers" - http://www.gaffer.org/networking-for-game-programmers
	Author: Glenn Fiedler <gaffer@gaffer.org>
*/

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

milessabin

import shapeless._

/**
 * Functional update of common fields of an *open* family of case classes
 * via a case-class-like copy through the common super type ...
 *
 * This is a follow up to my earlier post showin how to do functional
 * update for a sealed family of case classes,
 *
 *   https://gist.github.com/milessabin/a212d946aef33811fee1

milessabin

import shapeless._

object CaseClassMergeDemo extends App {
  import mergeSyntax._

  case class Foo(i: Int, s: String, b: Boolean)
  case class Bar(b: Boolean, s: String)

  val foo = Foo(23, "foo", true)
  val bar = Bar(false, "bar")

odersky

/** This is in reference to @tploecat's blog http://tpolecat.github.io/2015/04/29/f-bounds.html
 *  where he compares F-bounded polymorphism and type classes for implementing "MyType".
 * 
 *  Curiously, the in my mind obvious solution is missing: Use abstract types.
 * 
 *  A lot of this material, including an argument against F-bounded for the use-case
 *  is discussed in:
 * 
 *  Kim B. Bruce, Martin Odersky, Philip Wadler:
 *  A Statically Safe Alternative to Virtual Types. ECOOP 1998: 523-549