Re: [Tracker] Live queries

[Adrien Bustany <abustany gnome org>]

Writeback and GraphUpdated are actually not that different, in the
sense that they both signal updates to the outer world. They also both
apply to only certain statements (filtered with tracker:notify for
GraphUpdated, and tracker:writeback for writeback). One difference
between GraphUpdated and the writeback signal is that GraphUpdated
signals are batched together (for performance reasons), so it's not
exactly real time.
What exactly are you missing with GraphUpdated? The fact that it
involves IPC?

Cheers

Adrien

Le Sun, 28 Aug 2011 12:00:07 +0200,
Anders Feder <lists anders feder dk> a écrit :

> Thanks. While studying the GraphUpdated interface, I stumbled upon
> the writeback feature. Apparently, it does essentially the equivalent
> of a live query: it populates a hash table with predicates to watch
> and takes an action every time data using one of these predicates is
> inserted or deleted in the store.
>
> Would it make sense, then, to make a more generic "stuff to watch" 
> mechanism that can be used by both writeback and live queries? Would 
> such a solution have any chance of being accepted into the main
> source tree?
>
> Anders Feder
>
> On 27-08-2011 13:02, Adrien Bustany wrote:
> > Hi Anders
> >
> > you might be interested in
> https://maemo.gitorious.org/maemo-af/libqtsparql-tracker/trees/master/src/live 
>   ,
> > which is "live query" implementation on top of qsparql, Qt's
> > library to access Tracker (and other RDF stores). I've never used
> > myself, but it's used in several places in the Harmattan operating
> > system, so it must be working somehow ;)
> > If you were to start your own implementation (for example, GLib
> > based), I'd guess it'd sit on top of libtracker-sparql and the DBus
> > GraphUpdated signal...
> >
> > Cheers
> >
> > Adrien
> >
> > Le Sat, 27 Aug 2011 00:00:44 +0200,
> > Anders Feder<lists anders feder dk>  a écrit :
> >
> > > Hi,
> > >
> > > So, I finally managed to compile from source. I noted that in your
> > > wiki you list "live queries" / "views" as a thing you would like to
> > > implement in the future. I too am interested in such a feature, and
> > > was wondering if anyone could please me give some pointers as to
> > > how I might go about working on this item? I.e. where in the
> > > codebase would you add this functionality, are there any other
> > > changes that must be made first, etc. Thanks,
> > >
> > > Anders Feder
> > >
> > > lør, 07 05 2011 kl. 23:49 +0300, skrev Ivan Frade:
> > > hi,
> > > >   it could be that you don't have the introspection.m4 file? check
> > > > that you have the gobject-introspection packages installed. then
> > > > try to start from scratch, with git clean -dfx (beware this will
> > > > remove any file that you have added!) and the usual autogen.sh and
> > > > make.
> > > >
> > > >   hope this helps,
> > > >
> > > > ivan.
> > > >
> > > >
> > > > On 5/7/11, Anders Feder<lists anders feder dk>  wrote:
> > > > > Hi,
> > > > >
> > > > > When trying to build the latest version of Tracker from git on
> > > > > Ubuntu 11.04, I get the following error:
> > > > >
> > > > > autoreconf: running: automake --add-missing --copy
> > > > > --force-missing src/libtracker-extract/Makefile.am:76:
> > > > > HAVE_INTROSPECTION does not appear in AM_CONDITIONAL
> > > > > src/libtracker-extract/Makefile.am:77: INTROSPECTION_CFLAGS must
> > > > > be set with `=' before using `+='
> > > > > src/libtracker-miner/Makefile.am:149: HAVE_INTROSPECTION does not
> > > appear
> > > > > in AM_CONDITIONAL
> > > > > src/libtracker-miner/Makefile.am:150: INTROSPECTION_CFLAGS must
> > > > > be set with `=' before using `+='
> > > > > src/libtracker-sparql/Makefile.am:82: HAVE_INTROSPECTION does not
> > > appear
> > > > > in AM_CONDITIONAL
> > > > > autoreconf: automake failed with exit status: 1
> > > > >
> > > > > Any idea what might be causing this? Thanks,
> > > > >
> > > > > Anders Feder
> > > > >
> > > > >
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