[libvirt] [PATCH 03/13] Refactor domain events to handle multiple event types

[Daniel Veillard]

On Fri, Mar 19, 2010 at 03:38:51PM +0000, Daniel P. Berrange wrote:
> The internal domain events APIs are designed to handle the lifecycle
> events. This needs to be refactored to allow arbitrary new event
> types to be handled.
> 
>  * The signature of virDomainEventDispatchFunc changes to use
>    virConnectDomainEventGenericCallback instead of the lifecycle
>    event specific virConnectDomainEventCallback
>  * Every registered callback gains a unique ID to allow its
>    removal based on ID, instead of function pointer
>  * Every registered callback gains an 'eventID' to allow callbacks
>    for different types of events to be distinguished
>  * virDomainEventDispatch is adapted to filter out callbacks
>    whose eventID does not match the eventID of the event being
>    dispatched
>  * virDomainEventDispatch is adapted to filter based on the
>    domain name and uuid, if this filter is set for a callback.
>  * virDomainEvent type/detail fields are moved into a union to
>    allow different data fields for other types of events to be
>    added later
> 
> * src/conf/domain_event.h, src/conf/domain_event.c: Refactor
>   to allow handling of different types of events
> * src/lxc/lxc_driver.c, src/qemu/qemu_driver.c,
>   src/remote/remote_driver.c, src/test/test_driver.c,
>   src/xen/xen_driver.c: Change dispatch function signature
>   to use virConnectDomainEventGenericCallback
[...]
> diff --git a/src/conf/domain_event.c b/src/conf/domain_event.c
> index b520232..9d47eeb 100644
> --- a/src/conf/domain_event.c
> +++ b/src/conf/domain_event.c
> @@ -35,20 +35,36 @@
>      virReportErrorHelper(conn, VIR_FROM_THIS, code, __FILE__,       \
>                           __FUNCTION__, __LINE__, __VA_ARGS__)
>  
> +struct _virDomainMeta {
> +    int id;
> +    char *name;
> +    unsigned char uuid[VIR_UUID_BUFLEN];
> +};
> +typedef struct _virDomainMeta virDomainMeta;
> +typedef virDomainMeta *virDomainMetaPtr;
> +
>  struct _virDomainEventCallback {
> +    int callbackID;
> +    int eventID;
>      virConnectPtr conn;
> -    virConnectDomainEventCallback cb;
> +    virDomainMetaPtr dom;
> +    virConnectDomainEventGenericCallback cb;
>      void *opaque;
>      virFreeCallback freecb;
>      int deleted;
>  };
>  
>  struct _virDomainEvent {
> -    int id;
> -    char *name;
> -    unsigned char uuid[VIR_UUID_BUFLEN];
> -    int type;
> -    int detail;
> +    int eventID;
> +
> +    virDomainMeta dom;
> +
> +    union {
> +        struct {
> +            int type;
> +            int detail;
> +        } lifecycle;
> +    } data;
>  };
>  
>  /**

  Okay, that's logical, and most of the patch derives from that change,

[...]
> +static int virDomainEventDispatchMatchCallback(virDomainEventPtr event,
> +                                               virDomainEventCallbackPtr cb)
> +{
> +    if (!cb)
> +        return 0;
> +    if (cb->deleted)
> +        return 0;
> +    if (cb->eventID != event->eventID)
> +        return 0;
> +
> +    if (cb->dom) {
> +        /* Delibrately ignoring 'id' for matching, since that
> +         * will cause problems when a domain switches between
> +         * running & shutoff states */
> +
> +        if (STREQ(event->dom.name, cb->dom->name) &&
> +            (memcmp(event->dom.uuid, cb->dom->uuid, VIR_UUID_BUFLEN) == 0))
> +            return 1;

  Do we really need to match for both ?

> +        return 0;
> +    } else {
> +        return 1;
> +    }
> +}
> +
[...]

 ACK

Daniel

-- 
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