Re: [libvirt] [dbus PATCH 18/25] Implement PinEmulator method for Domain Interface

On Wed, Apr 18, 2018 at 02:41:19PM +0100, Daniel P. Berrangé wrote: > On Wed, Apr 18, 2018 at 03:03:20PM +0200, Pavel Hrdina wrote: > > On Tue, Apr 17, 2018 at 02:04:37PM +0200, Katerina Koukiou wrote: > > > Signed-off-by: Katerina Koukiou <kkoukiou(a)redhat.com&gt; > > > --- > > > data/org.libvirt.Domain.xml | 6 ++++++ > > > src/domain.c | 34 ++++++++++++++++++++++++++++++++++ > > > 2 files changed, 40 insertions(+) > > > > > > diff --git a/data/org.libvirt.Domain.xml b/data/org.libvirt.Domain.xml > > > index f2ef3dd..97c5471 100644 > > > --- a/data/org.libvirt.Domain.xml > > > +++ b/data/org.libvirt.Domain.xml > > > @@ -268,6 +268,12 @@ > > > value="See https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainMigrateStar... > > > <arg name="flags" type="u" direction="in"/> > > > </method> > > > + <method name="PinEmulator"> > > > + <annotation name="org.gtk.GDBus.DocString" > > > + value="See https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainPinEmulator... > > > + <arg name="cpumap" type="ay" direction="in"/> > > > > We need to figure out a better way how to represent the CPU map in > > libvirt-dbus. IMHO using an array of unsigned char is not the best > > from for D-Bus. > > > > There are two possible forms, using the string representation as we > > have in virsh, so for example "0,3-7,^5" which is 10011011. > > > > The second form is the one that libvirt-python uses, a tuple of boolean > > values, which in case of D-Bus would be represented as array of boolean > > values. > > array of boolean is better than array of char in that it is explicitly > typed. It is inefficient though - each boolean value takes up 32-bit on > the wire ! > > > The first form is better suited for humans so I guess we should go with > > the second form in D-Bus. > > Ultimately you should think about how a dbus client will consume the > data. If you use array of boolean, that all the DBus clients will > map that into native boolean types which are easy to acess for apps. > > If you use the string syntax, then every application has to write > parsing & formatting code for this syntax. I completely agree, that's why I suggested using an array of boolean.