Re: [Evolution-hackers] More e-d-s ABI breakage ?

[Harish Krishnaswamy <kharish novell com>]

On Fri, 2006-08-11 at 15:54 +0100, Michael Meeks wrote:
> Hi Harish,
> 
> 	First - thanks for digging these changes out for me. But - no, I'm not
> just interested in ebook (though for OO.o that is all), but I'm
> -primarily- interested Evo. itself, in being able to use and test the
> most recent version to help avoid regressions, and indeed ship it for
> older platforms.
> 
> 	So - if you could do the same for the other e-d-s libraries, it'd be
> great to see what changed there too.
> 
> On Fri, 2006-08-11 at 20:03 +0530, Harish Krishnaswamy wrote:
> > The changes in question are as follows :
> > http://cvs.gnome.org/viewcvs/evolution-data-server/addressbook/libebook/e-contact.h?r1=1.20&r2=1.21
> 
> 	So - this changed the EContactPhoto structure - why ? surely that is
> rather pointless. You could easily have added an EContactMimePhoto type
> and added a synthetic back-compat field that would handle the old case
> [ if it was of (whatever) mime type you expected ]. So - I see no
> problem at all doing this compatibly whatsoever. Perhaps a few more
> (~20) lines of code tops.
> 
I had not reviewed the patch or explored the alternatives to avoid
breakage. I would let the addressbook hackers to comment on that.
I do think you have a point above, though.

[1] OTH, I did approve the change into the release on the clear basis
that ferrying Photo images on Contacts was prohibitively hampering the
performance of the dbus port and the library had all to gain by ferrying
a url instead.

> > http://cvs.gnome.org/viewcvs/evolution-data-server/addressbook/libebook/e-contact.h?r1=1.21&r2=1.22
> 
> 	You converted a gpointer value to a 'const gpointer value' - I don't
> see that that is particularly necessary, or likely to break the ABI of
> anything unless it reflects some underlying lifecycle issue. Also the
> enum insertions were (this time) added at the end of the enumeration, so
> why should that break anything ? surely that's a compatible extension.

Point taken - The original patch would have introduced a break - this
was reworked as an append before it was committed.

> > 
> > The #313533 patch was vital for Ross Burton's dbus-based EDS and running
> > EDS on devices (say Nokia 770) would not be possible w/o this change.
> 
> 	Nonsense - at least the link above has no API change that is necessary
> for dbus or Nokia 770 support - unless I'm missing something huge; good
> buzz-words though :-) 
> 

I feel sorry to know you would think I would stoop to get around the
issue with buzzwords. 

http://www.burtonini.com/blog//2006/Jul/22

The performance tests showed this was prohibitive for EDS on DBUS.  

<quoting Devashish>
> I didn't explored the problem any deeper but appears that there is
> some problem with e_book_get_contacts code.
> 
> For detailed timing reports on this test download the following files
> and open them with sysprof.

See http://www.go-evolution.org/DBus_Port_of_EDS .

--Harish