def commit(self):
"""Commits the transaction.
This is called automatically upon exiting a with statement,
however it can be called explicitly
if you don't want to use a context manager.
This method has necessary side-effects:
- Sets the current connection's transaction reference to None.
- Sets the current transaction's ID to None.
- Updates paths for any keys that needed an automatically generated ID.
"""
# It's possible that they called commit() already, in which case
# we shouldn't do any committing of our own.
if self.connection().transaction():
result = self.connection().commit(self.dataset().id(), self.mutation())
# For any of the auto-id entities, make sure we update their keys.
for i, entity in enumerate(self._auto_id_entities):
key_pb = result.insert_auto_id_key[i]
key = Key.from_protobuf(key_pb)
entity.key(entity.key().path(key.path()))
# Tell the connection that the transaction is over.
self.connection().transaction(None)
# Clear our own ID in case this gets accidentally reused.
self._id = None
def from_protobuf(cls, pb):
entity = cls(key=Key.from_protobuf(pb.key))
for property_pb in pb.property:
value = helpers.get_value_from_protobuf(property_pb)
entity[property_pb.name] = value
return entity
def from_protobuf(cls, pb, dataset=None):
"""Factory method for creating an entity based on a protobuf.
The protobuf should be one returned from the Cloud Datastore Protobuf API.
:type key: :class:`gclouddatastore.datastore_v1_pb2.Entity`
:param key: The Protobuf representing the entity.
:returns: The :class:`Entity` derived from the :class:`gclouddatastore.datastore_v1_pb2.Entity`.
"""
# This is here to avoid circular imports.
from gclouddatastore import helpers
key = Key.from_protobuf(pb.key, dataset=dataset)
entity = cls.from_key(key)
for property_pb in pb.property:
value = helpers.get_value_from_protobuf(property_pb)
entity[property_pb.name] = value
return entity
def get_value_from_protobuf(pb):
"""Given a protobuf for a Property, get the correct value.
The Cloud Datastore Protobuf API returns a Property Protobuf
which has one value set and the rest blank.
This method retrieves the the one value provided.
Some work is done to coerce the return value into a more useful type
(particularly in the case of a timestamp value, or a key value).
:type pb: :class:`gclouddatastore.datastore_v1_pb2.Property`
:param pb: The Property Protobuf.
:returns: The value provided by the Protobuf.
"""
if pb.value.HasField('timestamp_microseconds_value'):
timestamp = pb.value.timestamp_microseconds_value / 1e6
return datetime.fromtimestamp(timestamp).replace(tzinfo=pytz.utc)
elif pb.value.HasField('key_value'):
return Key.from_protobuf(pb.value.key_value)
elif pb.value.HasField('boolean_value'):
return pb.value.boolean_value
elif pb.value.HasField('double_value'):
return pb.value.double_value
elif pb.value.HasField('integer_value'):
return pb.value.integer_value
elif pb.value.HasField('string_value'):
return pb.value.string_value
else:
# TODO(jjg): Should we raise a ValueError here?
return None
def save(self):
"""Save the entity in the Cloud Datastore.
:rtype: :class:`gclouddatastore.entity.Entity`
:returns: The entity with a possibly updated Key.
"""
key_pb = self.dataset().connection().save_entity(
dataset_id=self.dataset().id(), key_pb=self.key().to_protobuf(),
properties=dict(self))
# If we are in a transaction and the current entity needs an
# automatically assigned ID, tell the transaction where to put that.
transaction = self.dataset().connection().transaction()
if transaction and self.key().is_partial():
transaction.add_auto_id_entity(self)
if isinstance(key_pb, datastore_pb.Key):
updated_key = Key.from_protobuf(key_pb)
# Update the path (which may have been altered).
key = self.key().path(updated_key.path())
self.key(key)
return self
def save(self): key = self._connection.save_entity(self) self.key(Key.from_protobuf(key)) return self
