Now that properties can be explicitly registered as an enum
type, there is no need to pass the string table to the
object_get_enum() function. The object property registration
already has a pointer to the string table.
In changing this method signature, the hostmem backend object
has to be converted to use the new enum property registration
code, which simplifies it somewhat.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
A QOM property can be parsed as enum using the visit_type_enum()
helper function, but this forces callers to use the more complex
generic object_property_add() method when registering it. It
also requires that users of that object have access to the
string map when they want to read the property value.
This patch introduces a specialized object_property_add_enum()
method which simplifies the use of enum properties, so the
setters/getters directly get passed the int value.
typedef enum {
MYDEV_TYPE_FROG,
MYDEV_TYPE_ALLIGATOR,
MYDEV_TYPE_PLATYPUS,
MYDEV_TYPE_LAST
} MyDevType;
Then provide a table of enum <-> string mappings
static const char *const mydevtypemap[MYDEV_TYPE_LAST + 1] = {
[MYDEV_TYPE_FROG] = "frog",
[MYDEV_TYPE_ALLIGATOR] = "alligator",
[MYDEV_TYPE_PLATYPUS] = "platypus",
[MYDEV_TYPE_LAST] = NULL,
};
Assuming an object struct of
typedef struct {
Object parent_obj;
MyDevType devtype;
...other fields...
} MyDev;
The property can then be registered as follows:
static int mydev_prop_get_devtype(Object *obj,
Error **errp G_GNUC_UNUSED)
{
MyDev *dev = MYDEV(obj);
return dev->devtype;
}
static void mydev_prop_set_devtype(Object *obj,
int value,
Error **errp G_GNUC_UNUSED)
{
MyDev *dev = MYDEV(obj);
dev->devtype = value;
}
object_property_add_enum(obj, "devtype",
mydevtypemap, "MyDevType",
mydev_prop_get_devtype,
mydev_prop_set_devtype,
NULL);
Note there is no need to check the range of 'value' in
the setter, because the string->enum conversion code will
have already done that and reported an error as required.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
It is reasonably common to want to create an object, set a
number of properties, register it in the hierarchy and then
mark it as complete (if a user creatable type). This requires
quite a lot of error prone, verbose, boilerplate code to achieve.
First a pair of functions object_set_props() / object_set_propv()
are added which allow for a list of objects to be set in
one single API call.
Then object_new_with_props() / object_new_with_propv() constructors
are added which simplify the sequence of calls to create an
object, populate properties, register in the object composition
tree and mark the object complete, into a single method call.
Usage would be:
Error *err = NULL;
Object *obj;
obj = object_new_with_propv(TYPE_MEMORY_BACKEND_FILE,
object_get_objects_root(),
"hostmem0",
&err,
"share", "yes",
"mem-path", "/dev/shm/somefile",
"prealloc", "yes",
"size", "1048576",
NULL);
Note all property values are passed in string form and will
be parsed into their required data types, using normal QOM
semantics for parsing from string format.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Daniel P. Berrange