Extensions Docs Server: Apps samples page

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

+# Copyright (c) 2012 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.
+
+from appengine_wrappers import db
+from appengine_wrappers import BlobReferenceProperty
+
+BLOB_REFERENCE_BLOBSTORE = 'BlobReferenceBlobstore'
+
+class _Model(db.Model):
+  key_ = db.StringProperty()
+  value = BlobReferenceProperty()
+
+class BlobReferenceStore(object):
+  """A wrapper around the datastore API that can store blob keys.
+  """
+  def __init__(self, branch):
+    self._branch = branch
+
+  def _Query(self, namespace, key):
+    return _Model.gql('WHERE key_ = :1', self._MakeKey(namespace, key)).get()
+
+  def _MakeKey(self, namespace, key):
+    return '.'.join([self._branch, namespace, key])
+
+  def Set(self, namespace, key, value):
+    _Model(key_=self._MakeKey(namespace, key), value=value).put()
+
+  def Get(self, namespace, key):
+    result = self._Query(namespace, key)
+    if not result:
+      return None
+    return result.value
+
+  def Delete(self, namespace, key):
+    result = self._Query(namespace, key)
+    if not result:
+      return None
+    blob_key = result.value
+    result.delete()
+    return blob_key