changing the parent of a KConfigGroup

[Oswald Buddenhagen]

On Thu, Jan 03, 2008 at 02:04:11PM -0600, Thomas Braxton wrote:
> On 1/3/08, Oswald Buddenhagen <ossi at kde.org> wrote:
> > > +    if (destination == source) {
> > > +         // simple optimization for when copying a group to a different
> > > +         // parent without changing the name
> > >
> > i tend to think that this optimization is pretty pointless in practice,
> > and as it adds complexity ...
> 
> it's for the case of copying a group to another config file but still
> using the same name, it avoids replacing the name with itself that it
> would do in the other loop.
> 
i know. ;)
my point was that it doesn't happen particularly often, so the added
complexity might not be worth it. anyway, see below.

> > it would make sense to consider a truly hierarchical entry map at
> > this point. i have some ideas if you want to start on that.
> 
> sure, send your ideas and we'll see what we can make of them :)
>
ok. i think i'll simply extend the todo file. have to handle the mail
backlog first, though.

> Index: config/kconfig.cpp
> ===================================================================
> --- config/kconfig.cpp	(revision 755974)
> +++ config/kconfig.cpp	(working copy)
> @@ -113,6 +113,51 @@
>      return true;
>  }
>  
> +void KConfigPrivate::copyGroup(const QByteArray& source, const QByteArray& destination,
> +                                KConfigGroup *otherGroup) const
> +{
> + [...]
> +    if (destination == source) {
> + [...]
> +    } else {
> + [...]
> +            qDebug() << __PRETTY_FUNCTION__  << "copying...\n\told key = [" << group << ',' << key.mKey << ']';
> +            KEntryKey newKey = key;
> +            newKey.mGroup.replace(0, len, destination);
> +            qDebug() << "\tnew key = [" << newKey.mGroup << ',' << key.mKey << ']';
> + [...]
> +    }
> +}
> +
ok, assuming that the optimization *is* worth it: the two loops are
different only by the (non-) execution of the replacement. so put
the dest == src result into a bool and use it in an if in the loop -
branch prediction will do the rest. less code to read, maintain, etc.

> +++ config/kconfiggroup.cpp	(working copy)
> @@ -1270,3 +1270,30 @@
>  
> +void KConfigGroup::reparent(KConfigBase* parent)
> +    d = KConfigGroupPrivate::create(parent, d->mName, parent->isGroupImmutable(d->mName), false);
> +    oldGroup.copyTo(this);
>
reparenting an immutable group sort of makes no sense, so this needs
*some* special handling. i *guess* it would not really work as is now
anyway.

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