What's New in 0.5.x?

HUGE Speed Boost! Very few system calls!

Most of the data retrieved by the virtualbox library now comes via XML parsing, rather than making calls to VBoxManage. This results in a drastic speedup. The few relationships or attributes which require a system call are typically lazy loaded (covered below), so they don't incur a performance penalty unless they're used.

The one caveat is that you now need to set the path to the global VirtualBox configuration XML. The virtualbox library will do its best to guess this path based on the operating system, but this is hardly foolproof. To set the virtualbox config path, it is a simple one-liner:

# Remember, this won't be necessary MOST of the time
VirtualBox::Global.vboxconfig = "~/path/to/VirtualBox.xml"

Lazy Loading of Attributes and Relationships

Although still not widely used (will be in future patch releases), some attributes and relationships are now lazy loaded. This means that since they're probably expensive to load (many system calls, heavy parsing, etc.) they aren't loaded initially. Instead, they are only loaded if they're used. This means that you don't incur the penalty cost of loading them unless you use it! Fantastic!

There is no real "example code" for this feature since to the casual user, it happens transparently in the background and generally "just works." If you're really curious, then feel free to check out any class which derives from VirtualBox::AbstractModel and any attribute or relationship with the :lazy => true option is lazy loaded!

System Properties

A small but meaningful update is the ability to view the system properties for the host system which VirtualBox is running. This is done via the VirtualBox::SystemProperty class, which is simply a Hash. System properties are immutable properties defined by the host system, which typically are limits imposed upon VirtualBox, such as maximum RAM size or default path to machine files. Retrieving the system properties is quite easy:

properties = VirtualBox::SystemProperty.all
properties.each do |key, value|
  puts "#{key} = #{value}"

USB Device Relationship on VMs

Previously, VM object would only be able to tell you if there were USB devices enabled or not. Now, usbs is a full-fledged relationship on VM. This relationship is access just like any other. For more information view the USB class.