xref: /aosp_15_r20/external/autotest/utils/frozen_chromite/third_party/oauth2client/file.py (revision 9c5db1993ded3edbeafc8092d69fe5de2ee02df7) 
1# Copyright 2014 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"""Utilities for OAuth.
16
17Utilities for making it easier to work with OAuth 2.0
18credentials.
19"""
20
21import os
22import threading
23
24from oauth2client.client import Credentials
25from oauth2client.client import Storage as BaseStorage
26
27
28__author__ = '[email protected] (Joe Gregorio)'
29
30
31class CredentialsFileSymbolicLinkError(Exception):
32    """Credentials files must not be symbolic links."""
33
34
35class Storage(BaseStorage):
36    """Store and retrieve a single credential to and from a file."""
37
38    def __init__(self, filename):
39        self._filename = filename
40        self._lock = threading.Lock()
41
42    def _validate_file(self):
43        if os.path.islink(self._filename):
44            raise CredentialsFileSymbolicLinkError(
45                'File: %s is a symbolic link.' % self._filename)
46
47    def acquire_lock(self):
48        """Acquires any lock necessary to access this Storage.
49
50        This lock is not reentrant.
51        """
52        self._lock.acquire()
53
54    def release_lock(self):
55        """Release the Storage lock.
56
57        Trying to release a lock that isn't held will result in a
58        RuntimeError.
59        """
60        self._lock.release()
61
62    def locked_get(self):
63        """Retrieve Credential from file.
64
65        Returns:
66            oauth2client.client.Credentials
67
68        Raises:
69            CredentialsFileSymbolicLinkError if the file is a symbolic link.
70        """
71        credentials = None
72        self._validate_file()
73        try:
74            f = open(self._filename, 'rb')
75            content = f.read()
76            f.close()
77        except IOError:
78            return credentials
79
80        try:
81            credentials = Credentials.new_from_json(content)
82            credentials.set_store(self)
83        except ValueError:
84            pass
85
86        return credentials
87
88    def _create_file_if_needed(self):
89        """Create an empty file if necessary.
90
91        This method will not initialize the file. Instead it implements a
92        simple version of "touch" to ensure the file has been created.
93        """
94        if not os.path.exists(self._filename):
95            old_umask = os.umask(0o177)
96            try:
97                open(self._filename, 'a+b').close()
98            finally:
99                os.umask(old_umask)
100
101    def locked_put(self, credentials):
102        """Write Credentials to file.
103
104        Args:
105            credentials: Credentials, the credentials to store.
106
107        Raises:
108            CredentialsFileSymbolicLinkError if the file is a symbolic link.
109        """
110        self._create_file_if_needed()
111        self._validate_file()
112        f = open(self._filename, 'w')
113        f.write(credentials.to_json())
114        f.close()
115
116    def locked_delete(self):
117        """Delete Credentials file.
118
119        Args:
120            credentials: Credentials, the credentials to store.
121        """
122        os.unlink(self._filename)
123