| 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 |
Picking the right architecture = Picking the right battles + Managing trade-offs
| #!/bin/sh | |
| ### | |
| # SOME COMMANDS WILL NOT WORK ON macOS (Sierra or newer) | |
| # For Sierra or newer, see https://github.com/mathiasbynens/dotfiles/blob/master/.macos | |
| ### | |
| # Alot of these configs have been taken from the various places | |
| # on the web, most from here | |
| # https://github.com/mathiasbynens/dotfiles/blob/5b3c8418ed42d93af2e647dc9d122f25cc034871/.osx |
In August 2007 a hacker found a way to expose the PHP source code on facebook.com. He retrieved two files and then emailed them to me, and I wrote about the issue:
http://techcrunch.com/2007/08/11/facebook-source-code-leaked/
It became a big deal:
http://www.techmeme.com/070812/p1#a070812p1
The two files are index.php (the homepage) and search.php (the search page)
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.
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.
| # Bash best practices and style-guide | |
| Just simple methods to keep the code clean. | |
| Inspired by [progrium/bashstyle](https://github.com/progrium/bashstyle) and [Kfir Lavi post](http://www.kfirlavi.com/blog/2012/11/14/defensive-bash-programming/). | |
| ## Quick big rules | |
| * All code goes in a function | |
| * Always double quote variables |
| # extracted from http//www.naturalearthdata.com/download/110m/cultural/ne_110m_admin_0_countries.zip | |
| # under public domain terms | |
| country_bounding_boxes = { | |
| 'AF': ('Afghanistan', (60.5284298033, 29.318572496, 75.1580277851, 38.4862816432)), | |
| 'AO': ('Angola', (11.6400960629, -17.9306364885, 24.0799052263, -4.43802336998)), | |
| 'AL': ('Albania', (19.3044861183, 39.624997667, 21.0200403175, 42.6882473822)), | |
| 'AE': ('United Arab Emirates', (51.5795186705, 22.4969475367, 56.3968473651, 26.055464179)), | |
| 'AR': ('Argentina', (-73.4154357571, -55.25, -53.628348965, -21.8323104794)), | |
| 'AM': ('Armenia', (43.5827458026, 38.7412014837, 46.5057198423, 41.2481285671)), |
| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <title></title> | |
| <link rel='stylesheet' type='text/css' href='' /> | |
| <meta http-equiv='content-type' content='text/html; charset=utf-8' /> | |
| <meta name='viewport' content='initial-scale=1.0 maximum-scale=1.0'> | |
| </head> | |
| <body> | |
| <script src=''></script> |
| #!/usr/bin/env sh | |
| ## | |
| # This is script with usefull tips taken from: | |
| # https://github.com/mathiasbynens/dotfiles/blob/master/.osx | |
| # | |
| # install it: | |
| # curl -sL https://raw.github.com/gist/2108403/hack.sh | sh | |
| # |
You may want to employ the Parcel backed boilerplate that implements the solution described below.
