I am very interested in this, especially in relation to bnd(tools). Some
thoughts.
The trick is to find strongly coupled packages. These are packages that are in
a cycle. A -> B -> C -> A. Normally I find that these packages should be in the
same bundle. In bnd (the current next branch) I already can calculate those
strongly connected packages. In general, I find that many, especially larger,
bundles consist of a number of subsystems.
These subsystems have dependencies on each other, however, by definition there
is no cycle between these subsystem dependencies (otherwise they would be
strongly connected and be part of the same subsystem).
I find that there are then the following types of subsystems:
API - Self contained, no internal dependencies. All exported/imported. Very few
dependencies. The OSGi specification packages are prime examples. Having
imports in these packages is always suspect. In my experience, API must be
maintained independently but carried in the bundle that implements the API.
Library - Exported code == implementation. Few imports, everything is exported
and in general packages are not substitutable.
Implementation - Private code. No exports, many imports, If it provides an API
it should carry the API packages.
Bridge - Connects an external subsystem to an internal subsystem. Imports impl.
code, no exports. This case is special because they tend to drag in a lot
dependencies that are only required when the dependency is already there. For
example, a subsystem can provide packages that make it useful in Spring. I.e.
it does not require Spring but when other people use spring the package can be
used in that connected world. Another example is bnd. It is an ant task but it
should only require ant when it runs inside ant.
What I am looking for is an extension to bndtools that allows me to visualize
this model and refactor the code accordingly. The techniques should be in bnd
(which is a restricted environment) and the GUI should be in bndtools, If
you're willing to work this way then I'd love to be your Google code mentor.
Kind regards,
Peter Kriens
On 17 mrt 2011, at 03:58, Tiger Gui wrote:
> Hi guys,
>
> Recently, i am working on split my huge project in to many small
> sub-projects on OSGi way. Obviously, i want to use Felix as my OSGi
> framework, but as you know, this splitting job is a long and boring process.
> So, i am thinking that why can we build some tools for us to do this job ?
> I want to develop such a tool for Apache Felix, you guys have been working
> with Felix for a long time, so do you have any adivses about my project idea
> ? If you have any suggestions, please let me know, thank you.
>
> Meanwhile, i want to attend Google Summer of Code 2011 [1] with this
> project, this activity will help open source project development progress,
> but i must find a mentor to help me to participate in this activity
> together, so if you are interested, let me know too :-)
>
>
> [1] http://socghop.appspot.com/
>
>
> --
> Best Regards
> ----------------------------------------------------
> Tiger Gui [[email protected]]
