[josm-dev] Jumbo Patch

[Frederik Ramm]

Hi,

> The real problem here is a disconnection between the times when a
> Command is created and when it is executed.  How do we ever tell
> that a command is still _valid_? 

Maybe we could - this is now wild speculation, I haven't thought it
through properly - also add a cache on the OMSPrimitive object level
that tells us which commands have modified the object in question.
That would also help us find out which commands are still "valid",
would it not?

A very confusing thing about JOSM at the moment is that we completely
delete the command history whenever an upload has partly succeeded.
We have to do this because if we have uploaded at least one
modification, then *any* of the commands in the queue could have been
responsible for the modification, and we cannot allow the user to undo
anything lest he might undo the change we have already uploaded.

If we knew the commands which affected the objects already uploaded,
then we could make this more granular. Hmmmm, but what if half of the
objects affected by one command have been uploaded and not the other
half? 

Another angle from which we could approach this is uploading in the
order of the command history, i.e. when you upload, every single
command is "executed" on the server in the sequence you have entered
them. Then if things break, we can tell you exactly up to which point
in the history we have uploaded the changes. But this would create a
lot of unneccessary history information on the server (objects that
you have created, then moved, then deleted in one session...)

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00.09' E008°23.33'