[packagekit] viability of the current yum backend ?

[Robin Norwood]

Richard Hughes <hughsient at gmail.com> writes:

> On Thu, 2008-01-03 at 08:22 +0100, Tim Lauridsen wrote:
>> You are right, it sucks to setup yum each time we do some kind of 
>> packagekit backend action, the way to do it is have some kind of 
>> persistence yum object loaded one time and let the the helper script 
>> call it over DBUS.
>
> Agreed.

So how does this work, exactly?

Something like:

   C Backend                          Python Backend
       |
     Start
       |
 Start python backend --(exec and fork?)--Start
       |                                    |
       |                                    |
  Run an action ----------DBUS--------> (Do Stuff)
       |                                    |
 Receive results <--------DBUS--------- Send status update
       |                                    |
     (etc)                                (etc)
       |                                    | 
    Keep alive -----------DBUS----------->  OK
       |                                    |
     (etc)                                (etc)
       |                                    |
    "Die now" ------------DBUS----------->  OK (clean up and die)
       |                                    |
     Exit                                  Exit


(Sorry for the diagram)

Where the current backend lifecycle remains pretty much the same - It
starts upon receiving the first action from the frontend, and persists
for a certain amount of time after the last action in case another
action is on the way.  Except now, isntead of spawning a process for
each action, and waiting for the results on STDOUT/STDERR, it spawns a
single process, and talks to it over DBUS.  The python process sticks
around until it receives a "die now" from the backend, or it stops
getting 'keep alive' messages (in case the backend crashes).

Is this about what you're thinking?

-RN

-- 
Robin Norwood
Red Hat, Inc.

"The Sage does nothing, yet nothing remains undone."
-Lao Tzu, Te Tao Ching