luchuan

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

luchuan

# coding: utf-8
import yappi
import threading
from pybloom import BloomFilter


TEST_KEYS_NUM = 1000000
KEYS = [i for i in range(TEST_KEYS_NUM)]

luchuan

def golden_hash(value):
  num = hash(value)
  prime = 2654435761
  return (num * prime) % (2 ** 32)
  

luchuan

主仓库： https://github.com/owner/repo.git
开发仓库：https://github.com/collaborator/repo.git

开发准备：
git clone https://github.com/collaborator/repo.git
git remote -v （看一下是否有添加 upstream）
git remote add upstream https://github.com/owner/repo.git （如果没有，添加一下）
git pull upstream branchname（与主仓库最新的代码合并一下）

本地开发：

luchuan

# coding:utf-8
from random import randint, sample
from collections import Counter
from itertools import combinations


def gen_carts(items, n_cart):
    n_items = len(items)
    carts = []
    with open('carts.txt', 'w') as f:

luchuan

Process:         Xcode [46662]
Path:            /Applications/Xcode6-Beta.app/Contents/MacOS/Xcode
Identifier:      com.apple.dt.Xcode
Version:         6.0 (6194.21)
Build Info:      IDEFrameworks_KLONDIKE-6194021000000000~12
Code Type:       X86-64 (Native)
Parent Process:  launchd [901]
Responsible:     Xcode [46662]
User ID:         501

luchuan

// Playground - noun: a place where people can play

import Cocoa


func main() {

  func _fib(x: Int, y: Int, i: Int) -> Int {

    if i == 1 || i == 0 {

luchuan

# ----------------------------------------------------------------------------
# Makefile based on WinAVR Makefile Template written by Eric B. Weddington,
# Jörg Wunsch, et al.
#
#----------------------------------------------------------------------------
# On command line:
#
# make all = Make software.
#
# make clean = Clean out built project files.

luchuan

# coding:utf-8
import pcap
import dpkt
from datetime import datetime

pc = pcap.pcap()
pc.setfilter('tcp port 80')
for ptime, pdata in pc:
    print datetime.fromtimestamp(ptime).strftime('%Y-%m-%d %H:%M:%S')#, pdata
    p = dpkt.ethernet.Ethernet(pdata)

luchuan

#!/usr/bin/env python

# Copyright (c) 2011 Adam Pingel
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.