Docserver overhaul: Gitiles away from me.

chrome/common/extensions/docs/server2/datastore_models.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import cPickle
+import google.appengine.ext.db as db
+import logging
 import traceback
 
-from appengine_wrappers import db
+
+_MAX_ENTITY_SIZE = 1024*1024
+
 
 # A collection of the data store models used throughout the server.
 # These values are global within datastore.
 
 class PersistentObjectStoreItem(db.Model):
   pickled_value = db.BlobProperty()
 
   @classmethod
   def CreateKey(cls, namespace, key):
     path = '%s/%s' % (namespace, key)
     try:
       return db.Key.from_path(cls.__name__, path)
     except Exception:
       # Probably AppEngine's BadValueError for the name being too long, but
       # it's not documented which errors can actually be thrown here, so catch
       # 'em all.
       raise ValueError(
           'Exception thrown when trying to create db.Key from path %s: %s' % (
               path, traceback.format_exc()))
 
   @classmethod
   def CreateItem(cls, namespace, key, value):
+    pickled_value = cPickle.dumps(value)
+    if len(pickled_value) > _MAX_ENTITY_SIZE:
+      logging.warn('Refusing to create entity greater than 1 MB in size: %s/%s'
+                   % (namespace, key))
+      return None
     return PersistentObjectStoreItem(key=cls.CreateKey(namespace, key),
-                                     pickled_value=cPickle.dumps(value))
+                                     pickled_value=pickled_value)
 
   def GetValue(self):
     return cPickle.loads(self.pickled_value)