[Nepomuk] Redundant DBus communication

[David Faure]

Please run `dbus-monitor` on a KDE system now and then, to see all the DBus
communication coming out of nepomuk (I suppose this is especially happening
now because the akonadi_nepomuk_feeder agent is indexing all the existing email).

I see this, in particular: for every property, propertyAdded is emitted, followed by propertyChanged.
Surely a single signal could be used for this?

signal sender=:1.3181 -> dest=(null destination) serial=7023161 path=/resourcewatcher/watch27069; interface=org.kde.nepomuk.ResourceWatcherConnection; member=propertyAdded
   string "nepomuk:/res/4efdbd00-0b8a-44fe-bc8a-061966bdb2d9"
   string "http://www.semanticdesktop.org/ontologies/2007/03/22/nmo#isRead"
   array [
      variant          boolean false
   ]
signal sender=:1.3181 -> dest=(null destination) serial=7023162 path=/resourcewatcher/watch27069; interface=org.kde.nepomuk.ResourceWatcherConnection; member=propertyChanged
   string "nepomuk:/res/4efdbd00-0b8a-44fe-bc8a-061966bdb2d9"
   string "http://www.semanticdesktop.org/ontologies/2007/03/22/nmo#isRead"
   array [
      variant          boolean false
   ]
   array [
   ]

Another example, to show it's not related to "isRead":

signal sender=:1.3181 -> dest=(null destination) serial=7023137 path=/resourcewatcher/watch27069; interface=org.kde.nepomuk.ResourceWatcherConnection; member=propertyAdded
   string "nepomuk:/res/4efdbd00-0b8a-44fe-bc8a-061966bdb2d9"
   string "http://www.semanticdesktop.org/ontologies/2007/08/15/nao#prefSymbol"
   array [
      variant          string "nepomuk:/res/f36a5df4-7000-4678-9c71-1644ab76da00"
   ]
signal sender=:1.3181 -> dest=(null destination) serial=7023138 path=/resourcewatcher/watch27069; interface=org.kde.nepomuk.ResourceWatcherConnection; member=propertyChanged
   string "nepomuk:/res/4efdbd00-0b8a-44fe-bc8a-061966bdb2d9"
   string "http://www.semanticdesktop.org/ontologies/2007/08/15/nao#prefSymbol"
   array [
      variant          string "nepomuk:/res/f36a5df4-7000-4678-9c71-1644ab76da00"
   ]
   array [
   ]

For #prefLabel I even saw the nepomukstorage process emit propertyAdded+propertyChanged 6 times in a row,
for the same resource, with the same label.

-- 
David Faure, faure at kde.org, http://www.davidfaure.fr
Working on KDE, in particular KDE Frameworks 5