Fix #423: Expose the 'more_results' value fetched from the back-end.

gcloud/datastore/query.py

@@ -69,7 +69,7 @@ def __init__(self, kind=None, dataset=None, namespace=None):
  self._dataset = dataset
  self._namespace = namespace
  self._pb = datastore_pb.Query()
- self._cursor = None
+ self._cursor = self._more_results = None
  self._offset = 0
 
  if kind:
@@ -85,6 +85,7 @@ def _clone(self):
  namespace=self._namespace)
  clone._pb.CopyFrom(self._pb)
  clone._cursor = self._cursor
+ clone._more_results = self._more_results
  return clone
 
  def namespace(self):
@@ -347,21 +348,22 @@ def fetch(self, limit=None):
  dataset_id=self.dataset().id(),
  namespace=self._namespace,
  )
- # NOTE: `query_results` contains two extra values that we don't use,
- # namely `more_results` and `skipped_results`. The value of
- # `more_results` is unusable because it always returns an enum
+ # NOTE: `query_results` contains an extra value that we don't use,
+ # namely `skipped_results`.
+ #
+ # NOTE: The value of `more_results` is not currently useful because
+ # the back-end always returns an enum
  # value of MORE_RESULTS_AFTER_LIMIT even if there are no more
  # results. See
  # https://github.com/GoogleCloudPlatform/gcloud-python/issues/280
  # for discussion.
- entity_pbs, end_cursor = query_results[:2]
+ entity_pbs, self._cursor, self._more_results = query_results[:3]
 
- self._cursor = end_cursor
  return [helpers.entity_from_protobuf(entity, dataset=self.dataset())
  for entity in entity_pbs]
 
  def cursor(self):
- """Returns cursor ID
+ """Returns cursor ID from most recent ``fetch()``.
 
  .. warning:: Invoking this method on a query that has not yet
  been executed will raise a RuntimeError.
@@ -374,6 +376,28 @@ def cursor(self):
  raise RuntimeError('No cursor')
  return base64.b64encode(self._cursor)
 
+ def more_results(self):
+ """Returns ``more_results`` flag from most recent ``fetch()``.
+
+ .. warning:: Invoking this method on a query that has not yet
+ been executed will raise a RuntimeError.
+
+ .. note::
+
+ The `more_results` is not currently useful because it is
+ always returned by the back-end as ``MORE_RESULTS_AFTER_LIMIT``
+ even if there are no more results. See
+ https://github.com/GoogleCloudPlatform/gcloud-python/issues/280
+ for discussion.
+
+ :rtype: :class:`gcloud.datastore.datastore_v1_pb2.
+ QueryResultBatch.MoreResultsType`
+ :returns: enumerated value: are there more results available.
+ """
+ if self._more_results is None:
+ raise RuntimeError('No results')
+ return self._more_results
+
  def with_cursor(self, start_cursor, end_cursor=None):
  """Specifies the starting / ending positions in a query's result set.
 

gcloud/datastore/test_query.py

@@ -51,10 +51,12 @@ def test__clone(self):
  _DATASET = 'DATASET'
  _KIND = 'KIND'
  _CURSOR = 'DEADBEEF'
+ _MORE_RESULTS = 2
  _NAMESPACE = 'NAMESPACE'
  dataset = Dataset(_DATASET)
  query = self._makeOne(_KIND, dataset, _NAMESPACE)
  query._cursor = _CURSOR
+ query._more_results = _MORE_RESULTS
  clone = query._clone()
  self.assertFalse(clone is query)
  self.assertTrue(isinstance(clone, self._getTargetClass()))
@@ -63,6 +65,7 @@ def test__clone(self):
  kq_pb, = list(clone.kind())
  self.assertEqual(kq_pb.name, _KIND)
  self.assertEqual(clone._cursor, _CURSOR)
+ self.assertEqual(clone._more_results, _MORE_RESULTS)
 
  def test_to_protobuf_empty(self):
  query = self._makeOne()
@@ -317,6 +320,7 @@ def test_fetch_default_limit(self):
  self.assertEqual(connection._called_with, expected_called_with)
 
  def test_fetch_explicit_limit(self):
+ import base64
  from gcloud.datastore.datastore_v1_pb2 import Entity
  _CURSOR = 'CURSOR'
  _DATASET = 'DATASET'
@@ -336,7 +340,8 @@ def test_fetch_explicit_limit(self):
  query = self._makeOne(_KIND, dataset, _NAMESPACE)
  limited = query.limit(13)
  entities = query.fetch(13)
- self.assertEqual(query._cursor, _CURSOR)
+ self.assertEqual(query.cursor(), base64.b64encode(_CURSOR))
+ self.assertEqual(query.more_results(), connection._more)
  self.assertEqual(len(entities), 1)
  self.assertEqual(entities[0].key().path(),
  [{'kind': _KIND, 'id': _ID}])
@@ -347,6 +352,24 @@ def test_fetch_explicit_limit(self):
  }
  self.assertEqual(connection._called_with, expected_called_with)
 
+ def test_more_results_not_fetched(self):
+ _DATASET = 'DATASET'
+ _KIND = 'KIND'
+ connection = _Connection()
+ dataset = _Dataset(_DATASET, connection)
+ query = self._makeOne(_KIND, dataset)
+ self.assertRaises(RuntimeError, query.more_results)
+
+ def test_more_results_fetched(self):
+ _MORE_RESULTS = 2
+ _DATASET = 'DATASET'
+ _KIND = 'KIND'
+ connection = _Connection()
+ dataset = _Dataset(_DATASET, connection)
+ query = self._makeOne(_KIND, dataset)
+ query._more_results = _MORE_RESULTS
+ self.assertEqual(query.more_results(), _MORE_RESULTS)
+
  def test_cursor_not_fetched(self):
  _DATASET = 'DATASET'
  _KIND = 'KIND'
@@ -564,7 +587,7 @@ def connection(self):
 class _Connection(object):
  _called_with = None
  _cursor = ''
- _more = True
+ _more = 2
  _skipped = 0
 
  def __init__(self, *result):