liaoyw

import functools
import sys

def robust(expected, retry=3):
    def wrapper(func):
        @functools.wraps(func)
        def robust_run(*args, **kw):
            n = 0;
            result = None
            while n < retry:

liaoyw

import os
"""
as bash command: du -sb dir
+4906: add 4096bytes for the top dir
"""
def du_sb(dir):
 return sum(os.path.getsize(f) for f in reduce(lambda x,y:x+y, [[os.path.join(w[0], fe) for fe in w[1] + w[2]]  for w in os.walk(dir)])) + 4096;

def get_total_file_size(dir):
    return sum(os.path.getsize(f) for f in reduce(lambda x,y:x+y, [[os.path.join(w[0], fe) for fe in w[1] + w[2]]  for w in os.walk(dir)]) if os.path.isfile(f))

liaoyw

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

liaoyw

# copy from http://www.tldp.org/LDP/abs/html/sample-bashrc.html
function extract()      # Handy Extract Program
{
	if [ -f $1  ] ; then
		case $1 in
		*.tar.bz2)   tar xvjf $1     ;;
		*.tar.gz)    tar xvzf $1     ;;
		*.bz2)       bunzip2 $1      ;;
		*.rar)       unrar x $1      ;;
		*.gz)        gunzip $1       ;;

liaoyw

• http://the-paper-trail.org/blog/distributed-systems-theory-for-the-distributed-systems-engineer/
• https://github.com/palvaro/CMPS290S-Winter16/blob/master/readings.md
• http://muratbuffalo.blogspot.com/2015/12/my-distributed-systems-seminars-reading.html
• http://christophermeiklejohn.com/distributed/systems/2013/07/12/readings-in-distributed-systems.html
• http://michaelrbernste.in/2013/11/06/distributed-systems-archaeology-works-cited.html
• http://dancres.org/reading_list.html
• http://rxin.github.io/db-readings/
• http://research.microsoft.com/en-us/um/people/lamport/pubs/pubs.html
• http://www.eecs.berkeley.edu/GradAffairs/CS/Prelims/db.html
• http://pdos.csail.mit.edu/dsrg/papers/

liaoyw

# encoding: utf-8

import zlib

"""
copy from:
https://github.com/afirel/consistent_hashr/blob/master/lib/consistent_hashr.rb
http://www.tom-e-white.com/2007/11/consistent-hashing.html
"""
class ConsistentHash(object):

liaoyw

# open macdown from terminal
# from https://github.com/MacDownApp/macdown/wiki/Advanced-Usage

macdown() {
    "$(mdfind kMDItemCFBundleIdentifier=com.uranusjr.macdown | head -n1)/Contents/SharedSupport/bin/macdown" $@
}

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ping cn.bing.com | while read pong; do echo "$(date): $pong"; done

liaoyw

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

liaoyw

git_branch() {
    gb=$(git branch 2>/dev/null | grep '^*' | tr -d '* ')
    [[ ! -z $gb ]] && echo "($gb)"
}
export PS1="\\W\$(git_branch) $"