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

windviki

"""SQLAlchemy Metadata and Session object"""
from sqlalchemy import MetaData
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.orm.session import Session as SessionBase
from sqlalchemy.interfaces import ConnectionProxy

from datetime import datetime
import time

__all__ = ['Session', 'metadata', 'BaseModel']

dhh

bcx david$ rake stats
+----------------------+-------+-------+---------+---------+-----+-------+
| Name                 | Lines |   LOC | Classes | Methods | M/C | LOC/M |
+----------------------+-------+-------+---------+---------+-----+-------+
| Controllers          |  3704 |  2942 |      72 |     479 |   6 |     4 |
| Helpers              |  1901 |  1529 |      13 |     261 |  20 |     3 |
| Models               |  5310 |  4116 |      50 |     653 |  13 |     4 |
| Libraries            |  2167 |  1593 |      51 |     200 |   3 |     5 |
| Integration tests    |   297 |   217 |       6 |       1 |   0 |   215 |
| Functional tests     |  3897 |  3065 |      61 |      11 |   0 |   276 |

jrochkind

require 'date'

# Actually doesn't matter WHAT you choose as the epoch, it
# won't change the algorithm. Just don't change it after you
# have cached computed scores. Choose something before your first
# post to avoid annoying negative numbers. Choose something close
# to your first post to keep the numbers smaller. This is, I think,
# reddit's own epoch. 
$our_epoch = Time.local(2005, 12, 8, 7, 46, 43).to_time

JoshuaEstes

Moved to https://github.com/JoshuaEstes/CheatSheets

gnepud

ENV["RAILS_ENV"] = "test"
require File.expand_path('../../config/environment', __FILE__)
require 'rails/test_help'
require 'minitest/autorun'
require 'minitest/pride'
require 'capybara/rails'


class MiniTest::Spec
  include ActiveSupport::Testing::SetupAndTeardown

erikh

#!/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
#

ahawkins

# A Basic API Controller for Rails
# Handles authentication via Headers, params, and HTTP Auth
# Automatically makes all requests JSON format
#
# Written for production code
# Made public for: http://broadcastingadam.com/2012/03/state_of_rails_apis
#
# Enjoy!

class ApiController < ApplicationController

mrdanadams

$(function() {
    /* Convenience for forms or links that return HTML from a remote ajax call.
    The returned markup will be inserted into the element id specified.
     */
    $('form[data-update-target]').live('ajax:success', function(evt, data) {
        var target = $(this).data('update-target');
        $('#' + target).html(data);
    });
});