[Backalaika-developers] Singletons and a few design ideas

[Nando F. <nan...@ma...>]

Fabio Piemontesi wrote:
> Nando, I don't agree with the phrase, "SingleCall is stateful".
I meant "SingleCall is stateless", but it was 2:00 in the morning.

Having slept over my question, "why use the singleton pattern", I have 
come up with at least one good reason:

I complained in a previous message that the server-host only *contains* 
the remoted class, without any knowledge about it, since it is the 
client that creates an instance. But the singleton pattern contains a 
static variable which holds a reference to the single created instance, 
if any! This has the potential of solving that problem. If the 
server-host could get that reference and use it... I am going to try 
this today starting with the TempRemotingTest demo.


*A few design ideas*
*==================*
Only after backup is working (very soon now):
Keeping in mind that FileServers are accessed through 
"tcp://Computer:Port/uri":

- ProfileSingle shall include new properties "Computer" and "Port".

- "Computer" should be validated so it can't begin with "http:" or 
"tcp:". It also cannot contain "/" or ":". In fact, there's a lot of 
characters it shouldn't contain :)

- If more than one profile references the same "Computer" but with 
different ports, Admin user should be notified of a possible problem.

- BackupServer scans ProfilesList and realizes the time has come to make 
one scheduled backup. The info it needs to access the correct FileServer 
is right there in the profile.

- When Admin is creating the list of folders to be backed up, it can ask 
FileServer directly -- no need to go through BackupServer for this. So 
Admin is now a client for FileServer, only for the purpose of obtaining 
all of its folders.

Comments?

Nando