From a4bbc7c4fcea5596ab9f5a3d82983ddcf6d25909 Mon Sep 17 00:00:00 2001 From: Barry Warsaw Date: Wed, 6 Jan 2016 22:43:04 -0500 Subject: Additional refactoring to use the QuerySequence wrapper, so that we can still use len() and slicing on SQLAlchemy query results. We also don't need to list()-ify the results in the tests. This isn't perfect, but at least it doesn't introduce yet another layer violation. --- src/mailman/utilities/queries.py | 42 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 src/mailman/utilities/queries.py (limited to 'src/mailman/utilities/queries.py') diff --git a/src/mailman/utilities/queries.py b/src/mailman/utilities/queries.py new file mode 100644 index 000000000..6f4bc6b4d --- /dev/null +++ b/src/mailman/utilities/queries.py @@ -0,0 +1,42 @@ +# Copyright (C) 2016 by the Free Software Foundation, Inc. +# +# This file is part of GNU Mailman. +# +# GNU Mailman is free software: you can redistribute it and/or modify it under +# the terms of the GNU General Public License as published by the Free +# Software Foundation, either version 3 of the License, or (at your option) +# any later version. +# +# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for +# more details. +# +# You should have received a copy of the GNU General Public License along with +# GNU Mailman. If not, see . + +"""Some helpers for queries.""" + +__all__ = [ + 'QuerySequence', + ] + + +from collections.abc import Sequence + + +class QuerySequence(Sequence): + def __init__(self, query=None): + super().__init__() + self._query = query + self._cached_results = None + + def __len__(self): + return (0 if self._query is None else self._query.count()) + + def __getitem__(self, index): + if self._query is None: + raise IndexError('index out of range') + if self._cached_results is None: + self._cached_results = list(self._query) + return self._cached_results[index] -- cgit v1.2.3-70-g09d2