Argument store added to updateEntityProperties.
This argument determines if an entity should be stored in the data model after its properties are updated.
It may be useful, for example, along with tasks (Task Queue API). One may want to make some modifications to an entity during execution of a task, but the developer is sure that at least one new task, which also wants to modify the entity, will be queued, so he or she can just update the entity without saving the changes to the data model, set the entity in memcache and the following task (which is to be executed very shortly) is to retrive the current entity from the memcache (without any expensive calls to the actual data model).
#!/usr/bin/python2.5
#
# Copyright 2009 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""RankerRoot (Model) query functions.
"""
__authors__ = [
'"Lennard de Rijk" <ljvderijk@gmail.com>',
]
from google.appengine.api import datastore
from ranklist.ranker import Ranker
from soc.logic.models import base
import soc.models.ranker_root
class Logic(base.Logic):
"""Logic methods for the RankerRoot model.
"""
def __init__(self, model=soc.models.ranker_root.RankerRoot,
base_model=None, scope_logic=None):
"""Defines the name, key_name and model for this entity.
"""
super(Logic, self).__init__(model=model, base_model=base_model,
scope_logic=scope_logic)
def create(self, name, scope, scores, branching_factor):
"""Creates a new RankerRoot with a new Ranker.
Args:
name: the Link ID of the ranker root
scope: the entity owning the ranker
score_range: A list showing the range of valid scores, in the form:
[most_significant_score_min, most_significant_score_max,
less_significant_score_min, less_significant_score_max, ...]
Ranges are [inclusive, exclusive)
branching_factor: The branching factor of the tree. The number of
datastore Gets is Theta(1/log(branching_factor)), and the amount of data
returned by each Get is Theta(branching_factor).
"""
ranker = Ranker.Create(scores, branching_factor)
fields = {'link_id': name,
'scope': scope,
'scope_path': scope.key().id_or_name(),
'root': ranker.rootkey}
key_name = self.getKeyNameFromFields(fields)
self.updateOrCreateFromKeyName(fields, key_name)
def getRootFromEntity(self, entity):
"""Returns a Ranker object created from a RankerRoot entity.
Args:
entity: A RankerRoot entity which the root should be retrieved of
"""
return Ranker(datastore.Get(entity.key())['root'])
logic = Logic()