1# Copyright 2016 Google Inc. All rights reserved.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Dictionary storage for OAuth2 Credentials."""
16
17from oauth2client import client
18
19
20class DictionaryStorage(client.Storage):
21    """Store and retrieve credentials to and from a dictionary-like object.
22
23    Args:
24        dictionary: A dictionary or dictionary-like object.
25        key: A string or other hashable. The credentials will be stored in
26             ``dictionary[key]``.
27        lock: An optional threading.Lock-like object. The lock will be
28              acquired before anything is written or read from the
29              dictionary.
30    """
31
32    def __init__(self, dictionary, key, lock=None):
33        """Construct a DictionaryStorage instance."""
34        super(DictionaryStorage, self).__init__(lock=lock)
35        self._dictionary = dictionary
36        self._key = key
37
38    def locked_get(self):
39        """Retrieve the credentials from the dictionary, if they exist.
40
41        Returns: A :class:`oauth2client.client.OAuth2Credentials` instance.
42        """
43        serialized = self._dictionary.get(self._key)
44
45        if serialized is None:
46            return None
47
48        credentials = client.OAuth2Credentials.from_json(serialized)
49        credentials.set_store(self)
50
51        return credentials
52
53    def locked_put(self, credentials):
54        """Save the credentials to the dictionary.
55
56        Args:
57            credentials: A :class:`oauth2client.client.OAuth2Credentials`
58                         instance.
59        """
60        serialized = credentials.to_json()
61        self._dictionary[self._key] = serialized
62
63    def locked_delete(self):
64        """Remove the credentials from the dictionary, if they exist."""
65        self._dictionary.pop(self._key, None)
66