Jeff Raubitschek raubitsj

Channels Are Not Enough

... or Why Pipelining Is Not That Easy

Golang Concurrency Patterns for brave and smart.

Intro

Creating a redis Module in 15 lines of code!

A quick guide to write a very very simple "ECHO" style module to redis and load it. It's not really useful of course, but the idea is to illustrate how little boilerplate it takes.

Step 1: open your favorite editor and write/paste the following code in a file called module.c

#include "redismodule.h"
/* ECHO <string> - Echo back a string sent from the client */
int EchoCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {

Recently CSS has got a lot of negativity. But I would like to defend it and show, that with good naming convention CSS works pretty well.

My 3 developers team has just developed React.js application with 7668 lines of CSS (and just 2 !important). During one year of development we had 0 issues with CSS. No refactoring typos, no style leaks, no performance problems, possibly, it is the most stable part of our application.

Here are main principles we use to write CSS for modern (IE11+) browsers:

SUIT CSS naming conventions + SUIT CSS design principles;
PostCSS + CSSNext. Future CSS syntax like variables, nesting, and autoprefixer are good enough;
Flexbox is awesome. No need for grid framework;
Normalize.css, base styles and variables are solid foundation for all components;

OverEncrypt

This is a guide that I wrote to improve the default security of my website https://fortran.io , which has a certificate from LetsEncrypt. I'm choosing to improve HTTPS security and transparency without consideration for legacy browser support.

WARNING: if you mess up settings, lose your certificates, or decide to no longer maintain HTTPS certs, these steps can and will make your domain inaccessible.

I would recommend these steps only if you have a specific need for information security, privacy, and trust with your users, and/or maintain a separate secure.example.com domain which won't mess up your main site. If you've been thinking about hosting a site on Tor, then this might be a good option, too.

The best resources that I've found for explaining these steps are https://https.cio.gov , https://certificate-transparency.org , and https://twitter.com/konklone

	Latency Comparison Numbers (~2012)
	----------------------------------
	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

	Software for the Project:

	Raspbian Wheezy Debian Linux
	Win32Disk Imager
	The CanaKit comes with a pre-loaded SD card that includes the same version of Debian Wheezy that I used for this project. However, in an effort to get a little more speed out of the system, I used the 95MB/s Sandisk extreme listed above. It seemed to help, but I did not bench mark it beyond observation.

	Anyway, lets get down to building a Raspberry Pi Web Kiosk.

	Step 0: Get all of the hardware.
	Step 1: Get all of the software.

	android.permission.ACCESS_ALL_DOWNLOADS
	android.permission.ACCESS_BLUETOOTH_SHARE
	android.permission.ACCESS_CACHE_FILESYSTEM
	android.permission.ACCESS_CHECKIN_PROPERTIES
	android.permission.ACCESS_CONTENT_PROVIDERS_EXTERNALLY
	android.permission.ACCESS_DOWNLOAD_MANAGER
	android.permission.ACCESS_DOWNLOAD_MANAGER_ADVANCED
	android.permission.ACCESS_DRM_CERTIFICATES
	android.permission.ACCESS_EPHEMERAL_APPS
	android.permission.ACCESS_FM_RADIO