hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

tylerneylon

-- Two dashes start a one-line comment.

--[[
     Adding two ['s and ]'s makes it a
     multi-line comment.
--]]

----------------------------------------------------
-- 1. Variables and flow control.
----------------------------------------------------

jvns

I found understanding Rust types really confusing, so I wrote up a small tutorial for myself in an attempt to understand some of them. This is by no means exhaustive. There is a types section in the manual, but it has nowhere near enough examples.

I'm not talking about managed pointers (@) at all. A lot of the difficulty with Rust types is that the language is constantly changing, so this will likely be out of date soon.

First, a few preliminaries: it's easier to play with types if you have a REPL and can interactively check the types of objects. This isn't really possible in Rust, but there are workarounds.

To start out: some help

How to get a Rust REPL

lefticus

THIS DOCUMENT

IS OUT OF

DATE

See https://github.com/lefticus/cppbestpractices/blob/master/00-Table_of_Contents.md Instead!

C++ Coding Standards Part 0: Automated Code Analysis

Automated analysis is the main advantage to working with a modern statically typed compiled language like C++. Code analysis tools can inform us when we have implemented an operator overload with a non-canonical form, when we should have made a method const, or when the scope of a variable can be reduced.

rodneyrehm

some tools for diagrams in software documentation

Diagrams For Documentation

Obvious Choices

• Graphviz
• Pandoc

ASCII

kachayev

Channels Are Not Enough

... or Why Pipelining Is Not That Easy

Golang Concurrency Patterns for brave and smart.

By @kachayev

Intro

oakes

Contents

• Why care about Rust?
• The Toolchain
• Creating a New Project
• Modules
• Crates
• Types
• References
• Mutability

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

ctrlok

#!/bin/bash
# Simple script which decode and encode messages based on user github key.
# Usage:
#   Encrypt:
#     echo "My secret is" | ./ghcrypt.sh -u ctrlok
#   Decrypt:
#     echo "BASE64SCRET"  | ./ghcrypt.sh -k ~/.ssh/id_rsa


while getopts "u:k:" opt

ivanleoncz

#/usr/bin/python3
""" Demonstration of logging feature for a Flask App. """

from logging.handlers import RotatingFileHandler
from flask import Flask, request, jsonify
from time import strftime

__author__ = "@ivanleoncz"

import logging