jemmanuel

Latency Comparison Numbers
--------------------------
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

jemmanuel

Colours in terminal

It's a common confusion about terminal colours... Actually we have this:

• plain ascii
• ansi escape codes (16 colour codes with bold/italic and background)
• 256 colour palette (216 colours + 16 ansi + 24 gray) (colors are 24bit)
• 24bit true colour ("888" colours (aka 16 milion))

printf "\x1b[${bg};2;${red};${green};${blue}m\n"

jemmanuel

Ben's VirtualEnv Cheatsheet

This cheat sheet describes my usage/implementation of virtualenv with virtualenv wrapper and the bash foo that I added with the help of many blogs to make it all tick together in fun land.

Quick Reference

$ echo $WORKON_HOME
/Users/benjamin/.virtualenvs

$ echo $PROJECT_HOME