platform independent kdeinit/klauncher (was KDE4's IPC)

[Nicolas Goutte]

On Tuesday 27 December 2005 11:04, David Faure wrote:
> On Monday 26 December 2005 01:57, Thiago Macieira wrote:
> > >- is for application starting dcopserver/kdeinit/klauncher really
> > >required or is a low level implementation located in kdecore possible ?
> > >
> > >- is for kioslave process creating dcopserver/kdeinit/klauncher really
> > >required or is a low level implementation located in kdecore possible
> > >(perhaps using threads) ?
> >
> > In theory, both cases can be implemented as library code to be loaded by
> > any application. Therefore, kdeinit and klauncher would just be dedicated
> > applications to running those library functions.
>
> I'm not sure if you two have this in mind, but:
> kioslaves must be started by an external process (klauncher) so that they
> can be passed from a process to another. E.g. when you type a http address
> in minicli, minicli starts a GET, puts it on hold once it knows the
> mimetype, and then launches the associated application - which could be
> konqueror, or an image viewer, or a text editor, etc. - and that
> application resumes the downloading (by requesting to kio the same URL
> again). The goal is to
> 1) not use HTTP HEAD to get the mimetype, since it's broken on many servers
> 2) not do a HTTP GET twice because we are looking at the URL from two
> processes.

Especially that in KDE4 we should try to go further in this direction.

It should be avoid to have situations like suggested by some bug reports (for 
KIO) where you get three independant links (more or less at the same time):
-.one for the mime type
- one for the file information
- one for the thumbnail
or to try to get all these informations at the same time for each file of a 
whole remote directory (even if it is only a link per file).

Also it would be nice if the number of links to a single server could be 
limited, including down to maximum one link, as this seems to be needed by 
many FTP servers (implemented probably also through a white/black list of 
servers, where you you could tweak the number of links to a specific server 
URL).

(Yes, I know, it is a big wish and I will not implement it...)

>
> This is why kioslaves must be launched by a separate process, and not
> just by forking from the app. KDE_FORK_IOSLAVES breaks the above scenario.

Have a nice day!