[PATCH] Cache EF-PNN, EF-OPL sim files on disk.

[Denis Kenzior]

Hi,

> This uses plain files in /var/cache/ofono for storing contents of the
> operator lists to avoid possibly numerous queries to the SIM on every
> startup.  Files are indexed with IMSI.  I'm not 100% sure about the
> autoconf magic.
>
> Users need to rerun bootstrap-configure after applying this.
>
> File format slightly changed in this second version (make it as simple as
> possible).
>  		return -1;

I somewhat like the idea of transparently caching the SIM file system, 
unfortunately we can't do it for all files.  Suppose a user shuts off oFono 
device, takes out the SIM and puts it in another device.  Then modifies some 
settings (e.g. like MBDN or MSISDN.)  Then the SIM is returned to oFono based 
device.

However, not all files can be updated by the user.  Namely files with the 'ADM' 
for UPDATE access condition.  The only way they can be changed is at a service 
center.

What do you think of transparently caching only such files?  This would include 
the ones we're really interested in caching anyway, namely EFspn, EFpnn, 
EFopl, EFust, etc.

If we decide to do this, we should store them in /var/lib/ instead of 
/var/cache, since these files will be stored semi-permanently.  If really 
necessary, the carrier service center could probably remove the cache somehow 
during the SIM upgrade.

Regards,
-Denis