Sacha Arbonel sachaarbonel

Creating a "DMG installer" for OS X

A DMG Installer is convenient way to provide end-users a simple way to install an application bundle. They are basically a folder with a shortcut to the Applications directory but they can be customized with icons, backgrounds, and layout properties. A DMG file (.dmg) is a Mac OS X Disk Image file and it is used to package files or folders providing compression, encryption, and read-only to the package.

##Creating the DMG file #Disk Utility

Testing notes

Uncle Bob: Test First

Source: http://blog.8thlight.com/uncle-bob/2013/09/23/Test-first.html

tests are specs for the system and are more important than the system itself
(Tests should be) short, well factored, and well named. They ought to read like specifications; because they are specifications
(Goal:) trust your test suite to the extent that, if it passes, you know you

Turning PostgreSQL into a queue serving 10,000 jobs per second

RDBMS-based job queues have been criticized recently for being unable to handle heavy loads. And they deserve it, to some extent, because the queries used to safely lock a job have been pretty hairy. SELECT FOR UPDATE followed by an UPDATE works fine at first, but then you add more workers, and each is trying to SELECT FOR UPDATE the same row (and maybe throwing NOWAIT in there, then catching the errors and retrying), and things slow down.

On top of that, they have to actually update the row to mark it as locked, so the rest of your workers are sitting there waiting while one of them propagates its lock to disk (and the disks of however many servers you're replicating to). QueueClassic got some mileage out of the novel idea of randomly picking a row near the front of the queue to lock, but I can't still seem to get more than an an extra few hundred jobs per second out of it under heavy load.

So, many developers have started going straight t

Java to Dart

This is an ad-hoc Java-to-Dart translator originally written on two (admittedly long) evenings.

See http://sma.github.io/stuff/java2dartweb/java2dartweb.html for a demo.

Note: It doesn't support the complete Java grammar specification and cannot translate everything. It only translates syntax and does not attempt to translate Java library classes and methods to Dart equivalents (with the exception of String.charAt and StringBuffer.append). You will have to make changes to the resulting Dart code. It does not support anonymous inner classes.

However, I was able to successfully convert a 7000+ line command line application with only minimal fixes in 30 minutes.

	require './parser'
	require './nodes_eval'

	class Runtime
	def initialize
	@file = "test.log"
	end
	def loglines
	@lines = File.readlines(@file)
	@lines.each_with_index do \|line, index\|


	String sortedKey(List couple) {
	couple.sort();
	return Strings.concatAll(couple);
	}

	List mapper(Map m) {
	var res = [];
	for (var person in m.keys) {
	var friends = m[person];

	from BeautifulSoup import BeautifulSoup
	import requests
	import urlparse

	URL = 'example.com'
	s = requests.Session()

	def fetch(url, data=None):
	if data is None:
	return s.get(url).content

	import 'dart:core';
	import 'dart:async';
	import 'dart:io';

	void startServer() {
	Future<ServerSocket> serverFuture = ServerSocket.bind('0.0.0.0', 55555);
	serverFuture.then((ServerSocket server) {
	server.listen((Socket socket) {
	socket.listen((List<int> data) {
	String result = new String.fromCharCodes(data);

	#The MIT License (MIT)
	#
	#Copyright (c) 2015 Andre Queiroz
	#
	#Permission is hereby granted, free of charge, to any person obtaining a copy
	#of this software and associated documentation files (the "Software"), to deal
	#in the Software without restriction, including without limitation the rights
	#to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	#copies of the Software, and to permit persons to whom the Software is
	#furnished to do so, subject to the following conditions:

	package main

	import (
	"bytes"
	"fmt"
	"io"
	"log"
	"mime/multipart"
	"net/http"
	"os"