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

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 from appengine_wrappers import db
   6 from appengine_wrappers import BlobReferenceProperty
   7
   8 BLOB_REFERENCE_BLOBSTORE = 'BlobReferenceBlobstore'
   9
  10 class _Model(db.Model):
  11   key_ = db.StringProperty()
  12   value = BlobReferenceProperty()
  13
  14 class BlobReferenceStore(object):
  15   """A wrapper around the datastore API that can store blob keys.
  16   """
  17   def _Query(self, namespace, key):
  18     return _Model.gql('WHERE key_ = :1', self._MakeKey(namespace, key)).get()
  19
  20   def _MakeKey(self, namespace, key):
  21     return '.'.join((namespace, key))
  22
  23   def Set(self, namespace, key, value):
  24     _Model(key_=self._MakeKey(namespace, key), value=value).put()
  25
  26   def Get(self, namespace, key):
  27     result = self._Query(namespace, key)
  28     if not result:
  29       return None
  30     return result.value
  31
  32   def Delete(self, namespace, key):
  33     result = self._Query(namespace, key)
  34     if not result:
  35       return None
  36     blob_key = result.value
  37     result.delete()
  38     return blob_key