ahmadsamir added inline comments. INLINE COMMENTS
> dfaure wrote in openurljob.cpp:261 > LOL we're like an old couple, the explicit discussion doesn't actually need > to happen anymore ;) > > OK for everyone else, we're debating whether it's ok to use blocking > local-file I/O like QFile or QMimeDatabase which reads from the file. > > Of course less code paths is a good thing for maintenance, but it seems *so* > overkill to make two calls to a kioslave just to find out the mimetype of a > file.... My main counter argument is performance. > > For the whole OpenUrlJob until the mimetype is found: > > With KIO > > RESULT : OpenUrlJobTest::takeOverAfterMimeTypeFound(): > 0.29 msecs per iteration (total: 75, iterations: 256) > > With the local-file optimization > > RESULT : OpenUrlJobTest::takeOverAfterMimeTypeFound(): > 0.0986 msecs per iteration (total: 101, iterations: 1024) > > That's 3 times faster. Admittedly this is not the kind of things people do in > a loop. > > Well, OK, if nobody objects I can remove the local-files fast paths. > 0.2ms is nothing when lharming 2018 PG Demi Lovato Ashley Tisdale Avril > Lavigne-02052020.mpgaunching an app, or even when opening a URL in a browser. > > [More context: QMimeDatabase *might* determine the mimetype from just the > extension, in which case no I/O happens and we could do that here, or it > might need to look into the contents of the file. We can ask it to not do > that but then the mimetype determination will be less good, for some > mimetypes; and we can't ask it if we would get better information by looking > at content, so there's no way to split up the work between here and the > kioslave. It's "quick search" vs "full search", not phase 1, phase 2.] > OK for everyone else, we're debating whether it's ok to use blocking > local-file I/O like QFile or QMimeDatabase which reads from the file. I know this ship has sailed (well, sunk in this case :)), but if it's 3 times faster to use QFile, then is it really a "blocking I/O" operation? it's too fast to be "blocking"... REPOSITORY R241 KIO REVISION DETAIL https://phabricator.kde.org/D29385 To: dfaure, ahmadsamir, broulik, meven, kossebau, davidedmundson, nicolasfella, svuorela Cc: feverfew, kde-frameworks-devel, LeGast00n, cblack, michaelh, ngraham, bruns
