the-vampiire

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

Every so often I have to restore my gpg keys and I'm never sure how best to do it. So, I've spent some time playing around with the various ways to export/import (backup/restore) keys.

Method 1

Backup the public and secret keyrings and trust database

cp ~/.gnupg/pubring.gpg /path/to/backups/
cp ~/.gnupg/secring.gpg /path/to/backups/
cp ~/.gnupg/trustdb.gpg /path/to/backups/

or, instead of backing up trustdb...

Client-side SSL

For excessively paranoid client authentication.

Updated Apr 5 2019:

because this is a gist from 2011 that people stumble into and maybe you should AES instead of 3DES in the year of our lord 2019.

some other notes:

	// (c) copyright unscriptable.com / John Hann
	// License MIT
	// For more robust promises, see https://github.com/briancavalier/when.js.

	function Promise () {
	this._thens = [];
	}

	Promise.prototype = {

	var data = "do shash'owania";
	var crypto = require('crypto');
	crypto.createHash('md5').update(data).digest("hex");