Duncan Mac-Vicar P.

Some random thoughts about the world, and the past and following years.

Digital society

2007 was quite active on the digital rights topic.

The inability of the industry to catch up with the current society has created a war on digital rights. Software patents on one side. Digital music transformed music labels into mafias and consumers into rival groups. Politicians trying to implement surveillance systems everywhere.

I have the feeling that we will see some progress on the music topic. Record labels will give up, but it will be too late, and if a bunch of major artists start to use some fair system. Something like amiestreet.com or direct selling comes to my mind.

I don’t think something will happen on patents.

It was funny, some weeks ago I got an idea about using gps to associate location to todo items. This plays well with the getting things done methodology where you organize by contexts and not categories. I started prototyping some stuff on android.

Sadly, I found out this simple idea was patented by Fujitsu. Not only that. But I found a program which does that, and the website dissapeared. Another news article about someone researching on the topic and developing a product on that also dissapeared from the map. However, I haven’t yet seen a product from Fujitsu on the topic (the patent is 7 years old). Software patents destroy innovation. Thanks to that stupid patent, you won’t see any product (unless free software) using that.

The web 2.0

Everybody is sick of the Web 2.0 buzz. The Web 2.0 exists.

It is normal that consultants/analysts start to invent new terms because their business depends on the next “big thing” that will “cut costs” and “save millions” to your company. They repeat the same year after year just replacing the term itself.

However the amount of services on the web is growing really fast, and they are all accessible by really standard protocols. Software is becoming just a support medium and the value is being transfered to services: information, storage, security, etc.

Now, there are new layers over that. Phones with gps will bring a new dimension of services based on our location. This is very important. The information we store on the web becomes more relevant if we map it over real-world dimensions: location, time, mood, energy, context. Open source fits here, you can see companies like Google taking advantage of it.

Question: How services will affect open source and/or free software itself? Google contributes quite a lot to open source software. But once you don’t distribute the software, you are not forced to publish modifications. Will other companies follow this path?

Amazon Web Services is another topic. The way they sell on demand “computing power”, “human processing”, “databases” and “storage” is simply amazing.

I would like to see more about “distributed” environments. I am disappointed on how I have to manage my information having 3 computers and one cell phone. There has to be something better than either being off-line and centralized or being online and ubiquitous (where network is available). I want to be ubiquitous, distributed, fail tolerant, and in a simple, pragmatic way. (I don’t want to setup a cluster on my devices).

What about the bubble?. Yes, there is a bubble. There are a bunch of companies that know what they are doing. And thousands of venture capital groups funding whoolalalhzuzu.com ajax websites which implement a calculator or whatever. Those dying is not a bubble, it is natural selection. Most people already know which ones will die after using them for 2 minutes.

I am really excited about the developments in this area and looking forward what is coming here. The direction is clear.

Software

• openSUSE / YaST

  I will leave this for a separate post.

• KDE 4.0

  4.0 is being released in a few days and you will see the most brave release of free software ever. A big bunch of new technologies and visions collected, cooked and packed inside a great community. And better, there is still no big place for politics in KDE, but technical arguments and user experience. Not that all desktops could say the same.

Software Development

Wow, what happened on 2007?

• Software configuration / Version Control

  The growing complexity of open source codebases, plus the need to maintain them for enterprise purposes, brought the topic of version control really hard on the blog sphere. Every blog and developer talked about git. Lot of talk about mercurial and bzr too. 3 version control systems being popular at the same time? The point is that being “distributed” is “the thing”. I personally switched to git, and it solved the “being distributed” part of working with 3 computers in different places. I want to see something like code.google.com with git support.

• Android

  Brilliant. I am waiting for the first phone. Some APIs are ugly. But still prettier than uggly guys that reinvent the wheel poorly, and worse, only on Windows.

Nothing that spectacular on other old topics:

• Java

  While Eclipse is a jewel. Sun is getting better but too slow to move. So slow that it is getting boring to watch.

• Ruby

  We saw the release of ruby 1.9 on December, a very important milestone. At the same time, JRuby is now fast and very compatible, and other implementations are also very active.

• C++

  Even more boring than Java eh?

Politics

• Chile

  The goverment of Michelle Bachelet whose goverment improvisation has made the country again miss the opportunity to develop quickly. Michelle has no strategy at all, so the hope for 2008 is that his sucking team don’t make more mistakes. The public transport system ( Transantiago ) has to start working somehow (both in operation and budget), because till now, it is a joke.

  The opposition hasn’t a good alternative. Nobody is willing to make the important change: universal free and good education, health and social care. Even Michelle, being a socialist, uses the private health and education system.

• Europa

  Spain’s election coming. Seems that Zapatero will be reelected, which seems reasonable. I am a little lost with german politics and I feel like living in a fantasy world. Time to change that. Still, Europe’s economy is going good and living here is awesome. I love it.

• USA

  Discussions on whether they should teach non-science on science class?. War. etc. Uhm… was I writing about a middle west country? I am sad, really sad to see a beautiful country being destroyed, destroying, hating and being hated by almost the entire world, and even worse, considered the biggest threat to the rest of the world.

  From latimes.com:

  36% of European poll respondents — who come from Italy, France, Germany, Britain, and Spain consider America as the No. 1 danger to world peace. Even 35% of American 16- to 24-year-olds identify their own country as the chief danger to peace. The poll was consistent with findings by the Pew Global Attitudes Project, which found that favorable ratings of the U.S. had declined in 26 of 33 countries over the last five years. Europeans next concerns are China, 19%; Iran 17%; Iraq 11%; North Korea 9%; Russia 5%.

  Elections aren’t this year. Lets see how it goes.

Richard Moore comment on Access Anxiety explains why Encapsulation is a good thing. I think both are missing the point. Nobody doubts that encapsulation is a good thing, and Michael Feathers tries to present ruby way as a more “relaxed” thing.

The author was comparing the ‘ruby style’ of direct access to member variables with the getter/setter pattern common in Java code

So what is the ruby style really?

The annoying thing about java setters is that they are functions. So you either start with them (which is overkill for simple things) or don’t use them and then you are lost when you want to add things like Richard showed.

Ruby on the other hand, makes it easy, because you can’t expose member variables, but you can very easily create default accessors.

Michael Feathers example is wrong. Usually you start by actually offering a simple default accessor.

class GlazeObject
  attr_accessor :store, :formatter

  def initialize
    @store = DefaultStore.new
    @formatter = DefaultFormatter.new
  end
end

Now, if you need something more special, like Richard example:

public void setFormatter(Formatter formatter) {
        this.formatter = formatter;
        this.expensive = doCalculation(formatter);
    }

You can just remove attr_accessor :formatter and add to the class:

class GlazeObject
  def formatter
    return @formatter
  end

  def formatter=(f)
    @formatter = f;
     @expensive = doCalculation(f);
  end
end

What is the difference? In ruby, for client code consuming this class, you always see obj.formatter for both cases. In java you have to start from the beginning copy-pasting repetitive accessor code if you don’t want to start changing obj.formatter to obj.getFormatter() and obj.formater = something to obj.setFormatter(something).

C# has a similar feature, called properties.

public class Person
{
  private int _age; 
  public int age
  {
   get
   {
     return _age;
   }
   set
   {
     _age = value;
   }
  }
} 

No matter if we start with a public variable called age, we can move it to setters and getters (which are the providers of encapsulation without having to change the operation mode from variables to functions.

After quite lot of hacking nights, I managed to get some yast2 ruby bindings improvements working.

You might know that ycp is not only a language, but a component technology. Every component using the YaST2 technology can be reused from other YaST components no matter what language they are written in, as long as there are bindings for that. That was the original intention of the ruby bindings.

So for example, there is a component call Storage, which is written in the ycp language. The component (well, it is really a namespace, but YaST sees it as a namespace component) is located in /usr/share/YaST2/modules/Storage.ycp (.ybc for the bytecode compiled version) and offers some medium level functions that YaST uses.

This component needs low level access to the system, for which there is another module called Libstorage ( located in /usr/share/YaST2/modules/LibStorage.pm ) which in this case is written in perl which is a language YaST supports as long as you follows some simple rules.

The reason is because libstorage is a C++ library, and there is no easy way to bind it to the YaST environment, but as YaST supports perl, you can generate perl bindings for the C++ library and all the library functionality will be available to other components in YaST.

So repeat after me. ycp is not only a language. It is a communication protocol, used by YaST component framework.

So, with the ruby bindings, you where able to do:

require 'yast'

m = YaST::Module.new("Storage")
dp = m.GetDiskPartition("/dev/sda1")
dp.each do | key, value |
  puts "#{key} #{value}"
end

But I was never happy with the syntax. The idea was that you construct a dynamic proxy for a YaST component and then call methods on it. This had some disadvantages:

• If the component did not exist, you did not get an error till the method call
• It was not possible to do introspection to the component, because the methods call where implemented using the method_missing hook. So basically the proxy responded to all methods and only raised an error if the equivalent call to the YaST side was not possible.

So I decided to look for a new approach. This is the result till now:

require 'yast'
require 'ycp/storage'

dp = YCP::Storage::GetDiskPartition("/dev/sda1")
dp.each do | key, value |
  puts "#{key} #{value}"
end

Oh yes, you notice. First, there is no need to instantiate the module, a classic require will do it. The bindings modify the built-in require method, so if you require something under ycp/, a module is created on the fly. A real module, a real symbol. You can also import it manually using YCP::import

Now, you can do this:

puts YCP::Storage.methods

When the module is imported, the symbols are declared in the module, so you can ask for them in the module. I still need to work on other symbol types, but it should be straight forward.

The last improvement is that I simplified the C part of the bindings a lot, and moved most of the magic to pure ruby code, which makes easier to work with.

Next improvement, the other way around, making nicer how to call ruby components from any other component.

Surprised to find out that Chris is writing Taskjuggler3 from scratch, and this time, in Ruby:

TaskJuggler 3.x is a from-scratch rewrite of TaskJuggler. It’s currently in its infancy and only supports a minimum feature set. It is not intended for users yet. Please join our developer forum if you are interested in contributing. In contrast to the 2.x version TaskJuggler 3.x is written in Ruby.

There is a git repository in

http://www.taskjuggler.org/git-repos/taskjuggler3.git

in case you want to give it a look.

I just commited support for using the user interface (yes, that is Qt, GTK or ncurses) from the ruby language:

require 'yast'
ui = YaST::Module.new("UI")
YaST::Ui::init("qt")
include YaST::Ui

t = HBox( Label("Welcome to Ruby!"), PushButton("Push me") )

puts "#{t.to_s} #{t.class}"

ui.OpenDialog(t)
ui.UserInput()

Result:

Martin Vidner succeeded in making possible to use YaST UI:: from the language bindings. This means you could write a complete module in Perl, and get the benefits of the abstracted Qt/ncurses/gtk user interface.

These changes means that my Ruby bindings will be able to support it too.

I also got the code as yast2-bindings-ruby in the build service, it doesn’t build yet, but soon will appear in the home:dmacvicar project.

Srinivasa Ragavan is working on Desktop status awareness, which means trying to do useful tasks when you are away from your computer. I pointed him to the Kopete motion-auto-away plugin I hacked some years ago in order to set the user away in the messaging client if no motion was detected in a webcam stream.

So today SCR (system configuration repository) works from Ruby. Also if you call Ruby from YCP and the Ruby module calls YaST, Ruby can’t find the library. I fixed that.

require 'yast'

m = YaST::Module.new("SCR")
m.Execute(".target.bash", "firefox")

Will launch firefox

require 'yast'

m = YaST::Module.new("SCR")
modules = m.Read(".proc.modules")
modules.each do | k, v |
  puts "#{k}:"
  v.each do | a, b |
    puts "    #{a} - #{b}"
  end
end

Will output:

de_cd:
    size - 40608
    used - 0
cdrom:
    size - 36896
    used - 2
ehci_hcd:
    size - 34956
    used - 0
... (more)

So, it is Hackweek. Hundreds of Novell engineers working on the things they are passionate about. A full week of fully innovation and cooperation.

You can see the flickr photos here. The ideas collected (more than 300, with a hundred in progress).

So what am I doing? There are a few ideas for YaST. YaST needs new light to evolve somewhere, and most of the ideas bring a step in this direction: Making it accessible from web services, other languages support, UI independence from the ycp language, etc.

YaST already has perl bindings and there are some modules written in Perl.

My project is bidirectional ruby support for YaST, and it works already.

So, in Ruby you could write:

module Foo
  def self.multiply_by_eight(a)
    return 8*a
  end

  def self.sum(a,b)
    return a+b;
  end

And then in a .ycp file:

{
    import "Foo";
    integer result = (integer) Foo::sum(2,3);
    UI::OpenDialog(
         `VBox(
         `Label(sformat("%1", result)),
         `PushButton("OK")
         )
         );
    UI::UserInput();
    UI::CloseDialog();
}

It works!!!!:

Now, we can do YaST in Ruby too, using the “yast” module for Ruby, lets try the Arch module from YaST (which is ycp code)

require 'yast'

m = YaST::Module.new("Arch")
puts m.sparc32
puts m.arch_short
puts m.is_xen

The output is:

false
x86_64
false

What about something more complex. The Storage module is a C++ library. In order to bind it easily with YaST and being able to use SWIG, YaST developers access it using the YaST perl-bindings to access the generated SWIG perl-bindings from the C++ library, so calling this from Ruby code would go from Ruby, to YCP, to Perl, to C++:

m = YaST::Module.new("Storage")
dp = m.GetDiskPartition("/dev/sda1")
dp.each do | key, value |
  puts "#{key} #{value}"
end

The output is:

nr 1
disk /dev/sda

I also tried to access the UI, but it does not work. Martin Vidner told me he is working on getting rid of this limitation. SCR access should be doable but I haven’t look at it yet.

I will decide tomorrow if I tune the code or I spend my 2 days left (I travel to aKademy on Friday) researching other stuff (probably I will spend it on YaST too).