jcasimir

Transactions

As your business logic gets complex you may need to implement transactions. The classic example is a bank funds transfer from account A to account B. If the withdrawal from account A fails then the deposit to account B should either never take place or be rolled back.

Basics

All the complexity is handled by ActiveRecord::Transactions. Any model class or instance has a method named .transaction. When called and passed a block, that block will be executed inside a database transaction. If there's an exception raised, the transaction will automatically be rolled back.

Example

indexzero

> var err = new Error('wtf?');
> JSON.stringify(err)
'{"stack":"Error: wtf?\\n    at [object Context]:1:11\\n    at Interface.<anonymous> (repl.js:179:22)\\n    at Interface.emit (events.js:64:17)\\n    at Interface._onLine (readline.js:153:10)\\n    at Interface._line (readline.js:408:8)\\n    at Interface._ttyWrite (readline.js:585:14)\\n    at ReadStream.<anonymous> (readline.js:73:12)\\n    at ReadStream.emit (events.js:81:20)\\n    at ReadStream._emitKey (tty_posix.js:307:10)\\n    at ReadStream.onData (tty_posix.js:70:12)","message":"wtf?"}'
> Object.keys(err);
[ 'stack', 'arguments', 'type', 'message' ]
> Object.getOwnPropertyDescriptor(err, 'stack');
{ get: [Function], set: [Function], enumerable: true, configurable: true }
> process.versions.v8
'3.1.8.26'

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

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

ombagrao22

<?php
/*
 * This is custom gateway for "Citrus Payement Sloution"
 * @created: 5 MARCH 2013
 * @author: Omprakash
 */

$nzshpcrt_gateways[$num]['name'] = 'Citrus Pay Gateway';
$nzshpcrt_gateways[$num]['internalname'] = 'citrus_pay_gateway';
$nzshpcrt_gateways[$num]['function'] = 'gateway_citrus_pay_gateway';

guifromrio

How to: Setup Teamcity Agent on EC2 Ubuntu 12.04.2 Linux with front end tools

References:

• http://blog.bekijkhet.com/2012/05/install-teamcity-continuous-integration.html
• https://gist.github.com/ianbattersby/4641450

Install dependencies

sudo apt-get update

sandcastle

Install

Follow the steps below to install Team City 9.0.3 on Ubuntu with Nginx as the proxy for port 80.

Install Team City:

# will install on port 8111

sudo wget -c https://gist.githubusercontent.com/sandcastle/9282638/raw/teamcity-install.sh -O /tmp/teamcity-install.sh

codematix

{
	"caret_style": "solid",
	"color_scheme": "Packages/Tomorrow Color Schemes/Tomorrow-Night.tmTheme",
	"enable_tab_scrolling": false,
	"file_exclude_patterns":
	[
		"*.pyc",
		"*.pyo",
		"*.exe",
		"*.dll",

codematix

Documentation

1. Scheme - The scheme name consists of a sequence of characters beginning with a letter and followed by any combination of letters, digits, +, ., or -. Although schemes are case-insensitive, the canonical form is lowercase and documents that specify schemes must do so with lowercase letters. The scheme name is followed by a colon :.
2. Host Name - Hostname labels may contain only the ASCII letters a through z (in a case-insensitive manner), the digits 0 through 9, and the -. While a hostname may not contain other characters, such as the underscore character _, other DNS names may contain the underscore.
3. Port Number - A port number is a 16-bit unsigned integer, thus ranging from 0 to 65535.
4. Path - If present, may optionally begin with a single forward slash /. It may not begin with two slash characters //. The path is a sequence of segments (conceptually similar to directories, though not necessarily representing them) separated by a forward s

shibukawa

var m = require("mithril");

m.mount(document.querySelector("#menu"), {
    view: function() {
        return m("ul", [
            m("li", m('a[href="/a"]', {config: m.route}, "module A")),
            m("li", m('a[href="/b"]', {config: m.route}, "module B")),
            m("li", m('a[href="/c"]', {config: m.route}, "module C"))
        ]);
    }