hellerbarde

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

jboner

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

vjt

# Configuration suitable to display Apache/nginx access logs
# Based on conf.proftpd by Pavol Domin
# Crafted by Marcello Barnaba <[email protected]>

# Get GRC at http://kassiopeia.juls.savba.sk/~garabik/software/grc.html
#

# ip number
regexp=^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}
colours=bold magenta

vgoklani

# dropping a database via pymongo
from pymongo import Connection
c = Connection()
c.drop_database('mydatabase')

# drop a collection via pymongo
from pymongo import Connection
c = Connection()
c['mydatabase'].drop_collection('mycollection')

gregburek

import time

def RateLimited(maxPerSecond):
    minInterval = 1.0 / float(maxPerSecond)
    def decorate(func):
        lastTimeCalled = [0.0]
        def rateLimitedFunction(*args,**kargs):
            elapsed = time.clock() - lastTimeCalled[0]
            leftToWait = minInterval - elapsed
            if leftToWait>0:

vayn

# http://arcturo.github.com/library/coffeescript
javascript:(function(){var%20c=document.getElementById('container');c.style.width='720px';c.style.margin='0%20auto';})()

adhoc

#!/bin/bash

#####################################
#Author: Leon Lee                   #
#email: [email protected]       #
#QQ: 730395591                      #
#Version: 1.0                       #
#Note: If you have some good ideas  #
#	or advice, please mail me^^ #
#####################################

vayn

/**
 * Author:
 *    Vayn a.k.a. VT <[email protected]>
 *    http://vayn.is-programmer.com
 *
 * URL:
 *    http://p.vim-cn.com/cbG/js
 *
 * File:             googleImageSearch.js
 * Create Date:      2011年 06月 27日 星期一 09:29:57 CST

tkf

#!/usr/bin/env python

"""
Plot histogram from list of dates

Usage
=====
Feed newline separated unix time via STDIN.

Ex.1: plot repository activity::

williscool

// Expose modules in ./support for demo purposes

/**
 * Module dependencies.
  */

  var express = require('express');

  // Edit /etc/vhosts