def _gc_rule_from_pb(gc_rule_pb):
"""Convert a protobuf GC rule to a Python version.
:type gc_rule_pb: :class:`.data_pb2.GcRule`
:param gc_rule_pb: The GC rule to convert.
:rtype: :class:`GarbageCollectionRule`,
:class:`GarbageCollectionRuleUnion`,
:class:`GarbageCollectionRuleIntersection` or
:data:`NoneType <types.NoneType>`
:returns: An instance of one of the native rules defined
in :module:`column_family` or :data:`None` if no values were
set on the protobuf passed in.
:raises: :class:`ValueError <exceptions.ValueError>` if more than one
property has been set on the GC rule.
"""
all_fields = [field.name for field in gc_rule_pb._fields]
if len(all_fields) == 0:
return None
elif len(all_fields) > 1:
raise ValueError('At most one field can be set on a GC rule.')
field_name = all_fields[0]
if field_name == 'max_num_versions':
return GarbageCollectionRule(
max_num_versions=gc_rule_pb.max_num_versions)
elif field_name == 'max_age':
max_age = _duration_pb_to_timedelta(gc_rule_pb.max_age)
return GarbageCollectionRule(max_age=max_age)
elif field_name == 'union':
all_rules = gc_rule_pb.union.rules
return GarbageCollectionRuleUnion(
rules=[_gc_rule_from_pb(rule) for rule in all_rules])
elif field_name == 'intersection':
all_rules = gc_rule_pb.intersection.rules
return GarbageCollectionRuleIntersection(
rules=[_gc_rule_from_pb(rule) for rule in all_rules])
def _callFUT(self, duration_pb):
from gcloud_bigtable._helpers import _duration_pb_to_timedelta
return _duration_pb_to_timedelta(duration_pb)
