def reserve(self, context, resources, deltas, expire=None):
"""Check quotas and reserve resources.
For counting quotas--those quotas for which there is a usage
synchronization function--this method checks quotas against
current usage and the desired deltas.
This method will raise a QuotaResourceUnknown exception if a
given resource is unknown or if it does not have a usage
synchronization function.
If any of the proposed values is over the defined quota, an
OverQuota exception will be raised with the sorted list of the
resources which are too high. Otherwise, the method returns a
list of reservation UUIDs which were created.
:param context: The request context, for access checks.
:param resources: A dictionary of the registered resources.
:param deltas: A dictionary of the proposed delta changes.
:param expire: An optional parameter specifying an expiration
time for the reservations. If it is a simple
number, it is interpreted as a number of
seconds and added to the current time; if it is
a datetime.timedelta object, it will also be
added to the current time. A datetime.datetime
object will be interpreted as the absolute
expiration time. If None is specified, the
default expiration time set by
--default-reservation-expire will be used (this
value will be treated as a number of seconds).
"""
# Set up the reservation expiration
if expire is None:
expire = CONF.reservation_expire
if isinstance(expire, (int, long)):
expire = datetime.timedelta(seconds=expire)
if isinstance(expire, datetime.timedelta):
expire = timeutils.utcnow() + expire
if not isinstance(expire, datetime.datetime):
raise exception.InvalidReservationExpiration(expire=expire)
# Get the applicable quotas.
# NOTE(Vek): We're not worried about races at this point.
# Yes, the admin may be in the process of reducing
# quotas, but that's a pretty rare thing.
quotas = self._get_quotas(context,
resources,
deltas.keys(),
has_sync=True)
# NOTE(Vek): Most of the work here has to be done in the DB
# API, because we have to do it in a transaction,
# which means access to the session. Since the
# session isn't available outside the DBAPI, we
# have to do the work there.
return db.quota_reserve(context, resources, quotas, deltas, expire,
CONF.until_refresh, CONF.max_age)
def reserve(self, context, resources, deltas, expire=None):
"""Check quotas and reserve resources.
For counting quotas--those quotas for which there is a usage
synchronization function--this method checks quotas against
current usage and the desired deltas.
This method will raise a QuotaResourceUnknown exception if a
given resource is unknown or if it does not have a usage
synchronization function.
If any of the proposed values is over the defined quota, an
OverQuota exception will be raised with the sorted list of the
resources which are too high. Otherwise, the method returns a
list of reservation UUIDs which were created.
:param context: The request context, for access checks.
:param resources: A dictionary of the registered resources.
:param deltas: A dictionary of the proposed delta changes.
:param expire: An optional parameter specifying an expiration
time for the reservations. If it is a simple
number, it is interpreted as a number of
seconds and added to the current time; if it is
a datetime.timedelta object, it will also be
added to the current time. A datetime.datetime
object will be interpreted as the absolute
expiration time. If None is specified, the
default expiration time set by
--default-reservation-expire will be used (this
value will be treated as a number of seconds).
"""
# Set up the reservation expiration
if expire is None:
expire = CONF.reservation_expire
if isinstance(expire, (int, long)):
expire = datetime.timedelta(seconds=expire)
if isinstance(expire, datetime.timedelta):
expire = timeutils.utcnow() + expire
if not isinstance(expire, datetime.datetime):
raise exception.InvalidReservationExpiration(expire=expire)
# Get the applicable quotas.
# NOTE(Vek): We're not worried about races at this point.
# Yes, the admin may be in the process of reducing
# quotas, but that's a pretty rare thing.
quotas = self._get_quotas(context, resources, deltas.keys(),
has_sync=True)
# NOTE(Vek): Most of the work here has to be done in the DB
# API, because we have to do it in a transaction,
# which means access to the session. Since the
# session isn't available outside the DBAPI, we
# have to do the work there.
return db.quota_reserve(context, resources, quotas, deltas, expire,
CONF.until_refresh, CONF.max_age)