On Fri, Mar 09, 2012 at 06:49:20PM +0800, Osier Yang wrote:
> On 2012年03月09日 16:55, Daniel Veillard wrote:
> >On Mon, Mar 05, 2012 at 06:25:39PM +0800, Osier Yang wrote:
> >>This patch introduces a new event type for the QMP event
> >>DEVICE_TRAY_MOVED, which occurs when the tray of a removable
> >>disk is moved (i.e opened or closed):
> >>
> >> VIR_DOMAIN_EVENT_ID_TRAY_MOVED
> >>
> >>The event's data includes the device alias and the tray's
> >>status, which indicates whether the tray has been opened
> >>or closed. Thus the callback definition for the event is:
> >>
> >>typedef void
> >>(*virConnectDomainEventTrayMovedCallback)(virConnectPtr conn,
> >> virDomainPtr dom,
> >> const char *devAlias,
> >> unsigned int trayOpened,
> >> void *opaque);
> >
> > Hum ... could we make that slightly more generic.
> >Instead of just being able to report on tray opened or not (i.e. closed)
> >Let's report TrayChangeCallback, and have an 'int reason' instead.
>
> Hmm, yes, 'int reason' is good idea.
>
> But for the name, TrayMoved might describe the real action more
> precisely. Unlike DiskChange, it says there was some medium was
> changed, TrayMoved only intends to report the tray status changeing
> event, nothing really changed, or we can rename it to TrayStatusChange
> to indicate the tray status is changed, but IMO it's not much
> difference except getting a longer name. :-)
>
> >Then for example the API would be able to cope with more set of events,
> >one of the thing I can think of now would be the ability to emulate
> >multiple device in one as disk changers,
>
> What does "emulate multiple device" mean? is it "s/device/event/"?
Nahh, I was thinking of thinks like cdrom changers, where the
enclosure can hold multiple disks and swap them. But in retrospect
I dould we will have much need to emulate such hardware ever...
> and also possibly be able to
> >provide invormations about the kind of media, i.e. switch from a CD-ROM
> >to a DVD-WR in the tray.
>
> IMHO we should seperate the events for "tray change" and
> "medium change", the info such as the kind of media should handled
> by DiskChange instead,
yes, reasonnable.
> How about defining the callback like:
>
> /**
> * virConnectDomainEventTrayMovedReason:
> *
> * The reason describing why the callback was called
> */
> enum {
> VIR_DOMAIN_EVENT_TRAY_MOVED_OPEN = 0,
> VIR_DOMAIN_EVENT_TRAY_MOVED_CLOSE,
>
> /* Something else such as other driver only emits a
> * event for OPEN+CLOSE.
> */
>
> #ifdef VIR_ENUM_SENTINELS
> VIR_DOMAIN_EVENT_TRAY_MOVED_LAST
> #endif
> } virDomainEventTrayMovedReason;
>
>
> /**
> * virConnectDomainEventTrayMovedCallback:
> * @conn: connection object
> * @dom: domain on which the event occurred
> * @devAlias: device alias
> * @reason: reason why this callback was called, any of
> virDomainEventTrayMovedReason
> * @opaque: application specified data
> *
> * This callback occurs when the tray of a removable device is moved.
> *
> * The callback signature to use when registering for an event of type
> * VIR_DOMAIN_EVENT_ID_TRAY_MOVED wit virConnectDomainEventRegisterAny()
> */
> typedef void
> (*virConnectDomainEventTrayMovedCallback)(virConnectPtr conn,
> virDomainPtr dom,
> const char *devAlias,
> int reason,
> void *opaque);
I think I would still feel a bit better with Changed rather than Moved
which is more specific, but not a blocker.
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel@xxxxxxxxxxxx | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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