Ejemplo n.º 1
0
            def passes(entity):
                """ Returns True if the entity passes the filter, False otherwise. """
                entity_vals = entity.get(prop, [])
                if type(entity_vals) is not types.ListType:
                    entity_vals = [entity_vals]

                entity_property_list = [
                    datastore_types.ToPropertyPb(prop, value)
                    for value in entity_vals
                ]

                for entity_prop in entity_property_list:
                    fixed_entity_val = datastore_types.FromPropertyPb(
                        entity_prop)

                    for filter_prop in filt.property_list():
                        filter_val = datastore_types.FromPropertyPb(
                            filter_prop)

                        comp = u'%r %s %r' % (fixed_entity_val, op, filter_val)

                        logging.log(logging.DEBUG - 1,
                                    'Evaling filter expression "%s"', comp)

                        if eval(comp):
                            return True

                return False
    def __getattr__(self, prop_name):
        prop = self.__properties.get(prop_name)
        if not prop:
            raise AttributeError("entity for kind '%s' has no attribute '%s'" %
                                 (self.__key.kind(), prop_name))

        if isinstance(prop, list):
            converted = [datastore_types.FromPropertyPb(p) for p in prop]
        else:
            converted = datastore_types.FromPropertyPb(prop)

        # store on this object: don't call __getattr__ again
        setattr(self, prop_name, converted)
        return converted
Ejemplo n.º 3
0
def _get_beam_filters_from_ndb_filter_node(filter_node):
    """Returns an equivalent Apache Beam filter from the given NDB filter node.

    Args:
        filter_node: ndb_query.FilterNode. The filter node to convert.

    Returns:
        tuple(tuple(str, str, str)). The equivalent Apache Beam filters. Items
        are: (property name, comparison operator, property value).
    """
    if isinstance(filter_node, ndb_query.ConjunctionNode):
        nodes = list(filter_node._to_filter().filters) # pylint: disable=protected-access
    elif isinstance(filter_node, ndb_query.FilterNode):
        nodes = [filter_node._to_filter()] # pylint: disable=protected-access
    else:
        raise TypeError(
            '`!=`, `IN`, and `OR` are forbidden filters. To emulate their '
            'behavior, use multiple AND queries and flatten them into a single '
            'PCollection.')

    return [
        (
            pb.property(0).name(),
            datastore_query.PropertyFilter._OPERATORS_INVERSE[pb.op()], # pylint: disable=protected-access
            datastore_types.FromPropertyPb(pb.property(0)),
        )
        for pb in itertools.chain.from_iterable(n._to_pbs() for n in nodes) # pylint: disable=protected-access
    ]
 def __ProcessProperties(self, kind_name, namespace, prop_lists):
     for prop_list in prop_lists:
         for prop in prop_list:
             try:
                 value = datastore_types.FromPropertyPb(prop)
                 self.__AggregateProperty(kind_name, namespace, prop, value)
             except (AssertionError, AttributeError, TypeError,
                     ValueError), e:
                 logging.error('Cannot process property %r, exception %s' %
                               (prop, e))
Ejemplo n.º 5
0
  def _Dynamic_RunQuery(self, query, query_result):
    if not self.__tx_lock.acquire(False):
      raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST, 'Can\'t query inside a transaction.')
    else:
      self.__tx_lock.release()

    if query.has_offset() and query.offset() > _MAX_QUERY_OFFSET:
      raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST, 'Too big query offset.')

    num_components = len(query.filter_list()) + len(query.order_list())
    if query.has_ancestor():
      num_components += 1
    if num_components > _MAX_QUERY_COMPONENTS:
      raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST,
          ('query is too large. may not have more than %s filters'
           ' + sort orders ancestor total' % _MAX_QUERY_COMPONENTS))

    app = query.app()

    if self.__require_indexes:
      required, kind, ancestor, props, num_eq_filters = datastore_index.CompositeIndexForQuery(query)
      if required:
        required_key = kind, ancestor, props
        indexes = self.__indexes.get(app)
        if not indexes:
          raise apiproxy_errors.ApplicationError(
              datastore_pb.Error.NEED_INDEX,
              "This query requires a composite index, but none are defined. "
              "You must create an index.yaml file in your application root.")
        eq_filters_set = set(props[:num_eq_filters])
        remaining_filters = props[num_eq_filters:]
        for index in indexes:
          definition = datastore_admin.ProtoToIndexDefinition(index)
          index_key = datastore_index.IndexToKey(definition)
          if required_key == index_key:
            break
          if num_eq_filters > 1 and (kind, ancestor) == index_key[:2]:
            this_props = index_key[2]
            this_eq_filters_set = set(this_props[:num_eq_filters])
            this_remaining_filters = this_props[num_eq_filters:]
            if (eq_filters_set == this_eq_filters_set and
                remaining_filters == this_remaining_filters):
              break
        else:
          raise apiproxy_errors.ApplicationError(
              datastore_pb.Error.NEED_INDEX,
              "This query requires a composite index that is not defined. "
              "You must update the index.yaml file in your application root.")

    try:
      query.set_app(app)
      results = self.__entities[app, query.kind()].values()
      results = [entity.native for entity in results]
    except KeyError:
      results = []

    if query.has_ancestor():
      ancestor_path = query.ancestor().path().element_list()
      def is_descendant(entity):
        path = entity.key()._Key__reference.path().element_list()
        return path[:len(ancestor_path)] == ancestor_path
      results = filter(is_descendant, results)

    operators = {datastore_pb.Query_Filter.LESS_THAN:             '<',
                 datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL:    '<=',
                 datastore_pb.Query_Filter.GREATER_THAN:          '>',
                 datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL: '>=',
                 datastore_pb.Query_Filter.EQUAL:                 '==',
                 }

    for filt in query.filter_list():
      assert filt.op() != datastore_pb.Query_Filter.IN

      prop = filt.property(0).name().decode('utf-8')
      op = operators[filt.op()]

      filter_val_list = [datastore_types.FromPropertyPb(filter_prop)
                         for filter_prop in filt.property_list()]

      def passes(entity):
        """ Returns True if the entity passes the filter, False otherwise. """
        if prop in datastore_types._SPECIAL_PROPERTIES:
          entity_vals = self.__GetSpecialPropertyValue(entity, prop)
        else:
          entity_vals = entity.get(prop, [])

        if not isinstance(entity_vals, list):
          entity_vals = [entity_vals]

        for fixed_entity_val in entity_vals:
          if type(fixed_entity_val) in datastore_types._RAW_PROPERTY_TYPES:
            continue

          for filter_val in filter_val_list:
            fixed_entity_type = self._PROPERTY_TYPE_TAGS.get(
              fixed_entity_val.__class__)
            filter_type = self._PROPERTY_TYPE_TAGS.get(filter_val.__class__)
            if fixed_entity_type == filter_type:
              comp = u'%r %s %r' % (fixed_entity_val, op, filter_val)
            elif op != '==':
              comp = '%r %s %r' % (fixed_entity_type, op, filter_type)
            else:
              continue

            logging.log(logging.DEBUG - 1,
                        'Evaling filter expression "%s"', comp)

            try:
              ret = eval(comp)
              if ret and ret != NotImplementedError:
                return True
            except TypeError:
              pass

        return False

      results = filter(passes, results)

    def has_prop_indexed(entity, prop):
      """Returns True if prop is in the entity and is not a raw property, or
      is a special property."""
      if prop in datastore_types._SPECIAL_PROPERTIES:
        return True

      values = entity.get(prop, [])
      if not isinstance(values, (tuple, list)):
        values = [values]

      for value in values:
        if type(value) not in datastore_types._RAW_PROPERTY_TYPES:
          return True
      return False

    for order in query.order_list():
      prop = order.property().decode('utf-8')
      results = [entity for entity in results if has_prop_indexed(entity, prop)]

    def order_compare_entities(a, b):
      """ Return a negative, zero or positive number depending on whether
      entity a is considered smaller than, equal to, or larger than b,
      according to the query's orderings. """
      cmped = 0
      for o in query.order_list():
        prop = o.property().decode('utf-8')

        reverse = (o.direction() is datastore_pb.Query_Order.DESCENDING)

        if prop in datastore_types._SPECIAL_PROPERTIES:
          a_val = self.__GetSpecialPropertyValue(a, prop)
          b_val = self.__GetSpecialPropertyValue(b, prop)
        else:
          a_val = a[prop]
          if isinstance(a_val, list):
            a_val = sorted(a_val, order_compare_properties, reverse=reverse)[0]

          b_val = b[prop]
          if isinstance(b_val, list):
            b_val = sorted(b_val, order_compare_properties, reverse=reverse)[0]

        cmped = order_compare_properties(a_val, b_val)

        if o.direction() is datastore_pb.Query_Order.DESCENDING:
          cmped = -cmped

        if cmped != 0:
          return cmped

      if cmped == 0:
        return cmp(a.key(), b.key())

    def order_compare_properties(x, y):
      """Return a negative, zero or positive number depending on whether
      property value x is considered smaller than, equal to, or larger than
      property value y. If x and y are different types, they're compared based
      on the type ordering used in the real datastore, which is based on the
      tag numbers in the PropertyValue PB.
      """
      if isinstance(x, datetime.datetime):
        x = datastore_types.DatetimeToTimestamp(x)
      if isinstance(y, datetime.datetime):
        y = datastore_types.DatetimeToTimestamp(y)

      x_type = self._PROPERTY_TYPE_TAGS.get(x.__class__)
      y_type = self._PROPERTY_TYPE_TAGS.get(y.__class__)

      if x_type == y_type:
        try:
          return cmp(x, y)
        except TypeError:
          return 0
      else:
        return cmp(x_type, y_type)

    results.sort(order_compare_entities)

    offset = 0
    limit = len(results)
    if query.has_offset():
      offset = query.offset()
    if query.has_limit():
      limit = query.limit()
    if limit > _MAXIMUM_RESULTS:
      limit = _MAXIMUM_RESULTS
    results = results[offset:limit + offset]

    clone = datastore_pb.Query()
    clone.CopyFrom(query)
    clone.clear_hint()
    if clone in self.__query_history:
      self.__query_history[clone] += 1
    else:
      self.__query_history[clone] = 1
    self.__WriteHistory()

    self.__cursor_lock.acquire()
    cursor = self.__next_cursor
    self.__next_cursor += 1
    self.__cursor_lock.release()
    self.__queries[cursor] = (results, len(results))

    query_result.mutable_cursor().set_cursor(cursor)
    query_result.set_more_results(len(results) > 0)
Ejemplo n.º 6
0
  def _Dynamic_RunQuery(self, query, query_result):
    if query.has_transaction():
      self.__ValidateTransaction(query.transaction())
      if not query.has_ancestor():
        raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST,
          'Only ancestor queries are allowed inside transactions.')
      entities = self.__tx_snapshot
    else:
      entities = self.__entities

    app_id = query.app()
    namespace = query.name_space()
    self.__ValidateAppId(app_id)

    if query.has_offset() and query.offset() > _MAX_QUERY_OFFSET:
      raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST, 'Too big query offset.')

    num_components = len(query.filter_list()) + len(query.order_list())
    if query.has_ancestor():
      num_components += 1
    if num_components > _MAX_QUERY_COMPONENTS:
      raise apiproxy_errors.ApplicationError(
          datastore_pb.Error.BAD_REQUEST,
          ('query is too large. may not have more than %s filters'
           ' + sort orders ancestor total' % _MAX_QUERY_COMPONENTS))

    (filters, orders) = datastore_index.Normalize(query.filter_list(),
                                                  query.order_list())

    if self.__require_indexes:
      required, kind, ancestor, props, num_eq_filters = datastore_index.CompositeIndexForQuery(query)
      if required:
        required_key = kind, ancestor, props
        indexes = self.__indexes.get(app_id)
        if not indexes:
          raise apiproxy_errors.ApplicationError(
              datastore_pb.Error.NEED_INDEX,
              "This query requires a composite index, but none are defined. "
              "You must create an index.yaml file in your application root.")
        eq_filters_set = set(props[:num_eq_filters])
        remaining_filters = props[num_eq_filters:]
        for index in indexes:
          definition = datastore_index.ProtoToIndexDefinition(index)
          index_key = datastore_index.IndexToKey(definition)
          if required_key == index_key:
            break
          if num_eq_filters > 1 and (kind, ancestor) == index_key[:2]:
            this_props = index_key[2]
            this_eq_filters_set = set(this_props[:num_eq_filters])
            this_remaining_filters = this_props[num_eq_filters:]
            if (eq_filters_set == this_eq_filters_set and
                remaining_filters == this_remaining_filters):
              break
        else:
          raise apiproxy_errors.ApplicationError(
              datastore_pb.Error.NEED_INDEX,
              "This query requires a composite index that is not defined. "
              "You must update the index.yaml file in your application root.")

    try:
      query.set_app(app_id)
      datastore_types.SetNamespace(query, namespace)
      encoded = datastore_types.EncodeAppIdNamespace(app_id, namespace)
      if query.has_kind():
        results = entities[encoded, query.kind()].values()
        results = [entity.native for entity in results]
      else:
        results = []
        for key in entities:
          if key[0] == encoded:
            results += [entity.native for entity in entities[key].values()]
    except KeyError:
      results = []

    if query.has_ancestor():
      ancestor_path = query.ancestor().path().element_list()
      def is_descendant(entity):
        path = entity.key()._Key__reference.path().element_list()
        return path[:len(ancestor_path)] == ancestor_path
      results = filter(is_descendant, results)

    operators = {datastore_pb.Query_Filter.LESS_THAN:             '<',
                 datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL:    '<=',
                 datastore_pb.Query_Filter.GREATER_THAN:          '>',
                 datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL: '>=',
                 datastore_pb.Query_Filter.EQUAL:                 '==',
                 }

    def has_prop_indexed(entity, prop):
      """Returns True if prop is in the entity and is indexed."""
      if prop in datastore_types._SPECIAL_PROPERTIES:
        return True
      elif prop in entity.unindexed_properties():
        return False

      values = entity.get(prop, [])
      if not isinstance(values, (tuple, list)):
        values = [values]

      for value in values:
        if type(value) not in datastore_types._RAW_PROPERTY_TYPES:
          return True
      return False

    for filt in filters:
      assert filt.op() != datastore_pb.Query_Filter.IN

      prop = filt.property(0).name().decode('utf-8')
      op = operators[filt.op()]

      filter_val_list = [datastore_types.FromPropertyPb(filter_prop)
                         for filter_prop in filt.property_list()]

      def passes_filter(entity):
        """Returns True if the entity passes the filter, False otherwise.

        The filter being evaluated is filt, the current filter that we're on
        in the list of filters in the query.
        """
        if not has_prop_indexed(entity, prop):
          return False

        try:
          entity_vals = datastore._GetPropertyValue(entity, prop)
        except KeyError:
          entity_vals = []

        if not isinstance(entity_vals, list):
          entity_vals = [entity_vals]

        for fixed_entity_val in entity_vals:
          for filter_val in filter_val_list:
            fixed_entity_type = self._PROPERTY_TYPE_TAGS.get(
              fixed_entity_val.__class__)
            filter_type = self._PROPERTY_TYPE_TAGS.get(filter_val.__class__)
            if fixed_entity_type == filter_type:
              comp = u'%r %s %r' % (fixed_entity_val, op, filter_val)
            elif op != '==':
              comp = '%r %s %r' % (fixed_entity_type, op, filter_type)
            else:
              continue

            logging.log(logging.DEBUG - 1,
                        'Evaling filter expression "%s"', comp)

            try:
              ret = eval(comp)
              if ret and ret != NotImplementedError:
                return True
            except TypeError:
              pass

        return False

      results = filter(passes_filter, results)

    for order in orders:
      prop = order.property().decode('utf-8')
      results = [entity for entity in results if has_prop_indexed(entity, prop)]

    def order_compare_entities(a, b):
      """ Return a negative, zero or positive number depending on whether
      entity a is considered smaller than, equal to, or larger than b,
      according to the query's orderings. """
      cmped = 0
      for o in orders:
        prop = o.property().decode('utf-8')

        reverse = (o.direction() is datastore_pb.Query_Order.DESCENDING)

        a_val = datastore._GetPropertyValue(a, prop)
        if isinstance(a_val, list):
          a_val = sorted(a_val, order_compare_properties, reverse=reverse)[0]

        b_val = datastore._GetPropertyValue(b, prop)
        if isinstance(b_val, list):
          b_val = sorted(b_val, order_compare_properties, reverse=reverse)[0]

        cmped = order_compare_properties(a_val, b_val)

        if o.direction() is datastore_pb.Query_Order.DESCENDING:
          cmped = -cmped

        if cmped != 0:
          return cmped

      if cmped == 0:
        return cmp(a.key(), b.key())

    def order_compare_properties(x, y):
      """Return a negative, zero or positive number depending on whether
      property value x is considered smaller than, equal to, or larger than
      property value y. If x and y are different types, they're compared based
      on the type ordering used in the real datastore, which is based on the
      tag numbers in the PropertyValue PB.
      """
      if isinstance(x, datetime.datetime):
        x = datastore_types.DatetimeToTimestamp(x)
      if isinstance(y, datetime.datetime):
        y = datastore_types.DatetimeToTimestamp(y)

      x_type = self._PROPERTY_TYPE_TAGS.get(x.__class__)
      y_type = self._PROPERTY_TYPE_TAGS.get(y.__class__)

      if x_type == y_type:
        try:
          return cmp(x, y)
        except TypeError:
          return 0
      else:
        return cmp(x_type, y_type)

    results.sort(order_compare_entities)

    clone = datastore_pb.Query()
    clone.CopyFrom(query)
    clone.clear_hint()
    if clone in self.__query_history:
      self.__query_history[clone] += 1
    else:
      self.__query_history[clone] = 1

    cursor = _Cursor(query, results, order_compare_entities)
    self.__queries[cursor.cursor] = cursor

    if query.has_count():
      count = query.count()
    elif query.has_limit():
      count = query.limit()
    else:
      count = _BATCH_SIZE

    cursor.PopulateQueryResult(query_result, count, compile=query.compile())

    if query.compile():
      compiled_query = query_result.mutable_compiled_query()
      compiled_query.set_keys_only(query.keys_only())
      compiled_query.mutable_primaryscan().set_index_name(query.Encode())
Ejemplo n.º 7
0
    def _Dynamic_RunQuery(self, query, query_result):
        if query.keys_only():
            query_result.set_keys_only(True)

        num_components = len(query.filter_list()) + len(query.order_list())
        if query.has_ancestor():
            num_components += 1
        if num_components > _MAX_QUERY_COMPONENTS:
            raise apiproxy_errors.ApplicationError(
                datastore_pb.Error.BAD_REQUEST,
                ('query is too large. may not have more than %s filters'
                 ' + sort orders ancestor total' % _MAX_QUERY_COMPONENTS))

        app = query.app()

        query_result.mutable_cursor().set_cursor(0)
        query_result.set_more_results(False)

        if self.__require_indexes:
            (required, kind, ancestor, props,
             num_eq_filters) = (datastore_index.CompositeIndexForQuery(query))
            if required:
                index = entity_pb.CompositeIndex()
                index.mutable_definition().set_entity_type(kind)
                index.mutable_definition().set_ancestor(ancestor)
                for (k, v) in props:
                    p = index.mutable_definition().add_property()
                    p.set_name(k)
                    p.set_direction(v)

                if props and not self.__has_index(index):
                    raise apiproxy_errors.ApplicationError(
                        datastore_pb.Error.NEED_INDEX,
                        "This query requires a composite index that is not defined. "
                        "You must update the index.yaml file in your application root."
                    )

        collection = query.kind()
        if query.has_name_space():
            collection = query.name_space(
            ) + _NAMESPACE_CONCAT_STR + collection

        clone = datastore_pb.Query()
        clone.CopyFrom(query)
        clone.clear_hint()
        if clone in self.__query_history:
            self.__query_history[clone] += 1
        else:
            self.__query_history[clone] = 1

        # HACK we need to get one Entity from this collection so we know what the
        # property types are (because we need to construct queries that depend on
        # the types of the properties)...
        try:
            prototype = self.__db[collection].find_one()
        except pymongo.errors.InvalidName:
            raise datastore_errors.BadRequestError('query without kind')
        if prototype is None:
            return
        prototype = datastore.Entity._FromPb(
            self.__entity_for_mongo_document(prototype))

        spec = {}

        if query.has_ancestor():
            spec["_id"] = re.compile("^%s.*$" %
                                     self.__id_for_key(query.ancestor()))

        operators = {
            datastore_pb.Query_Filter.LESS_THAN: '<',
            datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL: '<=',
            datastore_pb.Query_Filter.GREATER_THAN: '>',
            datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL: '>=',
            datastore_pb.Query_Filter.EQUAL: '==',
        }

        for filt in query.filter_list():
            assert filt.op() != datastore_pb.Query_Filter.IN

            prop = filt.property(0).name().decode('utf-8')
            op = operators[filt.op()]

            filter_val_list = [
                datastore_types.FromPropertyPb(filter_prop)
                for filter_prop in filt.property_list()
            ]

            (key, value) = self.__filter_binding(prop, filter_val_list[0], op,
                                                 prototype)

            if key in spec:
                if (not isinstance(spec[key], types.DictType)
                        and not isinstance(value, types.DictType)):
                    if spec[key] != value:
                        return
                elif not isinstance(spec[key], types.DictType):
                    value["$in"] = [spec[key]]
                    spec[key] = value
                elif not isinstance(value, types.DictType):
                    spec[key]["$in"] = [value]
                else:
                    spec[key].update(value)
            else:
                spec[key] = value

        offset = 0
        # Cursor magic
        if query.has_compiled_cursor():
            offset, query_pb, unused_spec, incl = self._DecodeCompiledCursor(
                query.compiled_cursor())

        cursor = self.__db[collection].find(spec)

        order = self.__translate_order_for_mongo(query.order_list(), prototype)
        if order is None:
            return
        if order:
            cursor = cursor.sort(order)

        if query.offset() == datastore._MAX_INT_32:
            query.set_offset(0)
            query.set_limit(datastore._MAX_INT_32)

        if offset:
            cursor = cursor.skip(int(offset))
        elif query.has_offset() and query.offset() != _MAX_QUERY_OFFSET:
            cursor = cursor.skip(int(query.offset()))
        if query.has_limit():
            cursor = cursor.limit(int(query.limit()))

        self.__cursor_lock.acquire()
        cursor_index = self.__next_cursor
        self.__next_cursor += 1
        self.__cursor_lock.release()
        self.__queries[cursor_index] = cursor

        # Cursor magic
        compiled_cursor = query_result.mutable_compiled_cursor()
        position = compiled_cursor.add_position()
        query_info = self._MinimalQueryInfo(query)
        cloned_cursor = cursor.clone()
        results = list(cloned_cursor)
        if results:
            start_key = _CURSOR_CONCAT_STR.join(
                (str(len(results) + offset), query_info.Encode(),
                 self.__entity_for_mongo_document(results[-1]).Encode()))
            # Populate query result
            result_list = query_result.result_list()
            for doc in results:
                result_list.append(self.__entity_for_mongo_document(doc))
            query_result.set_skipped_results(len(results))
            position.set_start_key(str(start_key))
            position.set_start_inclusive(False)
        del cloned_cursor

        query_result.mutable_cursor().set_cursor(cursor_index)
        query_result.set_more_results(False)
Ejemplo n.º 8
0
    def _Dynamic_RunQuery(self, query, query_result):
        if query.has_transaction():
            if not query.has_ancestor():
                raise apiproxy_errors.ApplicationError(
                    datastore_pb.Error.BAD_REQUEST,
                    'Only ancestor queries are allowed inside transactions.')
        (filters, orders) = datastore_index.Normalize(query.filter_list(),
                                                      query.order_list())

        datastore_stub_util.FillUsersInQuery(filters)

        query_response = datastore_pb.QueryResult()
        query.set_app(self.__app_id)
        self._RemoteSend(query, query_response, "RunQuery")
        results = query_response.result_list()
        results = [datastore.Entity._FromPb(r) for r in results]

        if query.has_ancestor():
            ancestor_path = query.ancestor().path().element_list()

            def is_descendant(entity):
                path = entity.key()._Key__reference.path().element_list()
                return path[:len(ancestor_path)] == ancestor_path

            results = filter(is_descendant, results)

        operators = {
            datastore_pb.Query_Filter.LESS_THAN: '<',
            datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL: '<=',
            datastore_pb.Query_Filter.GREATER_THAN: '>',
            datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL: '>=',
            datastore_pb.Query_Filter.EQUAL: '==',
        }

        def has_prop_indexed(entity, prop):
            """Returns True if prop is in the entity and is indexed."""
            if prop in datastore_types._SPECIAL_PROPERTIES:
                return True
            elif prop in entity.unindexed_properties():
                return False

            values = entity.get(prop, [])
            if not isinstance(values, (tuple, list)):
                values = [values]

            for value in values:
                if type(value) not in datastore_types._RAW_PROPERTY_TYPES:
                    return True
            return False

        for filt in filters:
            assert filt.op() != datastore_pb.Query_Filter.IN

            prop = filt.property(0).name().decode('utf-8')
            op = operators[filt.op()]

            filter_val_list = [
                datastore_types.FromPropertyPb(filter_prop)
                for filter_prop in filt.property_list()
            ]

        for order in orders:
            prop = order.property().decode('utf-8')
            results = [
                entity for entity in results if has_prop_indexed(entity, prop)
            ]

        def order_compare_entities(a, b):
            """ Return a negative, zero or positive number depending on whether
      entity a is considered smaller than, equal to, or larger than b,
      according to the query's orderings. """
            cmped = 0
            for o in orders:
                prop = o.property().decode('utf-8')

                reverse = (o.direction() is
                           datastore_pb.Query_Order.DESCENDING)

                a_val = datastore._GetPropertyValue(a, prop)
                if isinstance(a_val, list):
                    a_val = sorted(a_val,
                                   order_compare_properties,
                                   reverse=reverse)[0]

                b_val = datastore._GetPropertyValue(b, prop)
                if isinstance(b_val, list):
                    b_val = sorted(b_val,
                                   order_compare_properties,
                                   reverse=reverse)[0]

                cmped = order_compare_properties(a_val, b_val)

                if o.direction() is datastore_pb.Query_Order.DESCENDING:
                    cmped = -cmped

                if cmped != 0:
                    return cmped

            if cmped == 0:
                return cmp(a.key(), b.key())

        def order_compare_entities_pb(a, b):
            """ Return a negative, zero or positive number depending on whether
      entity a is considered smaller than, equal to, or larger than b,
      according to the query's orderings. a and b are protobuf-encoded
      entities."""
            return order_compare_entities(datastore.Entity.FromPb(a),
                                          datastore.Entity.FromPb(b))

        def order_compare_properties(x, y):
            """Return a negative, zero or positive number depending on whether
      property value x is considered smaller than, equal to, or larger than
      property value y. If x and y are different types, they're compared based
      on the type ordering used in the real datastore, which is based on the
      tag numbers in the PropertyValue PB.
      """
            if isinstance(x, datetime.datetime):
                x = datastore_types.DatetimeToTimestamp(x)
            if isinstance(y, datetime.datetime):
                y = datastore_types.DatetimeToTimestamp(y)

            x_type = self._PROPERTY_TYPE_TAGS.get(x.__class__)
            y_type = self._PROPERTY_TYPE_TAGS.get(y.__class__)

            if x_type == y_type:
                try:
                    return cmp(x, y)
                except TypeError:
                    return 0
            else:
                return cmp(x_type, y_type)

        results.sort(order_compare_entities)

        clone = datastore_pb.Query()
        clone.CopyFrom(query)
        clone.clear_hint()
        clone.clear_limit()
        clone.clear_offset()
        #if clone in self.__query_history:
        #  self.__query_history[clone] += 1
        #else:
        #  self.__query_history[clone] = 1

        results = [r._ToPb() for r in results]
        for result in results:
            datastore_stub_util.PrepareSpecialPropertiesForLoad(result)

        datastore_stub_util.ValidateQuery(query, filters, orders,
                                          _MAX_QUERY_COMPONENTS)

        cursor = datastore_stub_util.ListCursor(query, results,
                                                order_compare_entities_pb)
        self.__queries[cursor.cursor] = cursor

        if query.has_count():
            count = query.count()
        elif query.has_limit():
            count = query.limit()
        else:
            count = _BATCH_SIZE

        cursor.PopulateQueryResult(query_result,
                                   count,
                                   query.offset(),
                                   compile=query.compile())

        if query.compile():
            compiled_query = query_result.mutable_compiled_query()
            compiled_query.set_keys_only(query.keys_only())
            compiled_query.mutable_primaryscan().set_index_name(query.Encode())
    def _Dynamic_RunQuery(self, query, query_result):
        if query.has_offset() and query.offset() > _MAX_QUERY_OFFSET:
            raise apiproxy_errors.ApplicationError(
                datastore_pb.Error.BAD_REQUEST, 'Too big query offset.')

        if query.keys_only():
            query_result.set_keys_only(True)

        num_components = len(query.filter_list()) + len(query.order_list())
        if query.has_ancestor():
            num_components += 1
        if num_components > _MAX_QUERY_COMPONENTS:
            raise apiproxy_errors.ApplicationError(
                datastore_pb.Error.BAD_REQUEST,
                ('query is too large. may not have more than %s filters'
                 ' + sort orders ancestor total' % _MAX_QUERY_COMPONENTS))

        app = query.app()

        query_result.mutable_cursor().set_cursor(0)
        query_result.set_more_results(False)

        if self.__require_indexes:
            required, kind, ancestor, props, num_eq_filters = datastore_index.CompositeIndexForQuery(
                query)
            if required:
                index = entity_pb.CompositeIndex()
                index.mutable_definition().set_entity_type(kind)
                index.mutable_definition().set_ancestor(ancestor)
                for (k, v) in props:
                    p = index.mutable_definition().add_property()
                    p.set_name(k)
                    p.set_direction(v)

                if props and not self.__has_index(index):
                    raise apiproxy_errors.ApplicationError(
                        datastore_pb.Error.NEED_INDEX,
                        "This query requires a composite index that is not defined. "
                        "You must update the index.yaml file in your application root."
                    )

        collection = query.kind()

        clone = datastore_pb.Query()
        clone.CopyFrom(query)
        clone.clear_hint()
        if clone in self.__query_history:
            self.__query_history[clone] += 1
        else:
            self.__query_history[clone] = 1

        # HACK we need to get one Entity from this collection so we know what the
        # property types are (because we need to construct queries that depend on
        # the types of the properties)...
        prototype = self.__db[collection].find_one()
        if prototype is None:
            return
        prototype = datastore.Entity._FromPb(
            self.__entity_for_mongo_document(prototype))

        spec = {}

        if query.has_ancestor():
            spec["_id"] = re.compile("^%s.*$" %
                                     self.__id_for_key(query.ancestor()))

        operators = {
            datastore_pb.Query_Filter.LESS_THAN: '<',
            datastore_pb.Query_Filter.LESS_THAN_OR_EQUAL: '<=',
            datastore_pb.Query_Filter.GREATER_THAN: '>',
            datastore_pb.Query_Filter.GREATER_THAN_OR_EQUAL: '>=',
            datastore_pb.Query_Filter.EQUAL: '==',
        }

        for filt in query.filter_list():
            assert filt.op() != datastore_pb.Query_Filter.IN

            prop = filt.property(0).name().decode('utf-8')
            op = operators[filt.op()]

            filter_val_list = [
                datastore_types.FromPropertyPb(filter_prop)
                for filter_prop in filt.property_list()
            ]

            (key, value) = self.__filter_binding(prop, filter_val_list[0], op,
                                                 prototype)

            if key in spec:
                if not isinstance(spec[key],
                                  types.DictType) and not isinstance(
                                      value, types.DictType):
                    if spec[key] != value:
                        return
                elif not isinstance(spec[key], types.DictType):
                    value["$in"] = [spec[key]]
                    spec[key] = value
                elif not isinstance(value, types.DictType):
                    spec[key]["$in"] = [value]
                else:
                    spec[key].update(value)
            else:
                spec[key] = value

        cursor = self.__db[collection].find(spec)

        order = self.__translate_order_for_mongo(query.order_list(), prototype)
        if order is None:
            return
        if order:
            cursor = cursor.sort(order)

        if query.has_offset():
            cursor = cursor.skip(query.offset())
        if query.has_limit():
            cursor = cursor.limit(query.limit())

        self.__cursor_lock.acquire()
        cursor_index = self.__next_cursor
        self.__next_cursor += 1
        self.__cursor_lock.release()
        self.__queries[cursor_index] = cursor

        query_result.mutable_cursor().set_cursor(cursor_index)
        query_result.set_more_results(True)