[virt-tools-list] [libosinfo 3/3] Utility function to retrieve device by property

[Zeeshan Ali (Khattak)]

On Thu, Jan 19, 2012 at 5:28 PM, Christophe Fergeau <cfergeau at redhat.com> wrote:
> On Thu, Jan 19, 2012 at 05:22:20PM +0200, Zeeshan Ali (Khattak) wrote:
>> On Thu, Jan 19, 2012 at 11:51 AM, Christophe Fergeau
>> <cfergeau at redhat.com> wrote:
>> > On Thu, Jan 19, 2012 at 02:37:07AM +0200, Zeeshan Ali (Khattak) wrote:
>> >> From: "Zeeshan Ali (Khattak)" <zeeshanak at gnome.org>
>> >>
>> >> ---
>> >>  osinfo/libosinfo.syms |    1 +
>> >>  osinfo/osinfo_os.c    |   41 +++++++++++++++++++++++++++++++++++++++++
>> >>  osinfo/osinfo_os.h    |    4 ++++
>> >>  3 files changed, 46 insertions(+), 0 deletions(-)
>> >>
>> >> diff --git a/osinfo/libosinfo.syms b/osinfo/libosinfo.syms
>> >> index de1ff18..8e2d929 100644
>> >> --- a/osinfo/libosinfo.syms
>> >> +++ b/osinfo/libosinfo.syms
>> >> @@ -109,6 +109,7 @@ LIBOSINFO_0.0.6 {
>> >>       osinfo_os_new;
>> >>       osinfo_os_get_devices;
>> >>       osinfo_os_get_all_devices;
>> >> +     osinfo_os_get_device_by_property;
>> >>       osinfo_os_get_device_links;
>> >>       osinfo_os_add_device;
>> >>       osinfo_os_get_family;
>> >> diff --git a/osinfo/osinfo_os.c b/osinfo/osinfo_os.c
>> >> index 0facb08..ec7886a 100644
>> >> --- a/osinfo/osinfo_os.c
>> >> +++ b/osinfo/osinfo_os.c
>> >> @@ -238,6 +238,47 @@ OsinfoDeviceList *osinfo_os_get_all_devices(OsinfoOs *os, OsinfoFilter *filter)
>> >>  }
>> >>
>> >>  /**
>> >> + * osinfo_os_get_device_by_property:
>> >> + * @os: an operating system
>> >> + * @property: the property of interest
>> >> + * @value: the required value of property @property
>> >> + * @inherited: Should devices from inherited and cloned OSs be included in the
>> >> + * search.
>> >> + *
>> >> + * A utility function that gets the first device found from the list of devices
>> >> + * @os supports, for which the value of @property is @value.
>> >> + *
>> >> + * Returns: (transfer full): The found device or NULL
>> >> + */
>> >> +OsinfoDevice *osinfo_os_get_device_by_property(OsinfoOs *os,
>> >> +                                               const gchar *property,
>> >> +                                               const gchar *value,
>> >> +                                               gboolean inherited)
>> >> +{
>> >> +    OsinfoDevice *ret;
>> >> +    OsinfoDeviceList *devices;
>> >> +    OsinfoFilter *filter;
>> >> +
>> >> +    filter = osinfo_filter_new();
>> >> +    osinfo_filter_add_constraint(filter, property, value);
>> >> +
>> >> +    if (inherited)
>> >> +        devices = osinfo_os_get_all_devices(os, filter);
>> >> +    else
>> >> +        devices = osinfo_os_get_devices(os, filter);
>> >> +    g_object_unref (filter);
>> >
>> > Don't you get a warning if you don't do g_object_unref(G_OBJECT(filter)); ?
>> > (same comment for the g_object_unref(devices) below)
>>
>> Nope, should I be?
>
> It probably depends on your CFLAGS, but I'm quite sure I got warnings
> in some occasions without the casts.
>
>>
>> >> +
>> >> +    if (osinfo_list_get_length(OSINFO_LIST(devices)) > 0)
>> >> +        ret = OSINFO_DEVICE (osinfo_list_get_nth(OSINFO_LIST(devices), 0));
>> >
>> > I think it would be better to return the full list and let the app decide whether
>> > it wants the first item in the list or more than that.
>>
>> I guess, we can provide another function 'get_devices_by_property'  as well..
>
> What kind of properties do we get? Does it really make sense to only return
> the first one and ignore the other results? I don't know what kind of
> results this function returns, so hardcoding in the library this kind of
> "arbitrarily pick one result, drop the rest" makes me uncomfortable.

https://bugzilla.gnome.org/show_bug.cgi?id=668229

-- 
Regards,

Zeeshan Ali (Khattak)
FSF member#5124