1# Copyright 2013 The Chromium Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5"""Abstract injector class for GS requests."""
6
7
8class FileNotFoundError(Exception):
9  """Thrown by a subclass of CloudBucket when a file is not found."""
10  pass
11
12
13class BaseCloudBucket(object):
14  """An abstract base class for working with GS."""
15
16  def UploadFile(self, path, contents, content_type):
17    """Uploads a file to GS.
18
19    Args:
20      path: where in GS to upload the file.
21      contents: the contents of the file to be uploaded.
22      content_type: the MIME Content-Type of the file.
23    """
24    raise NotImplementedError
25
26  def DownloadFile(self, path):
27    """Downsloads a file from GS.
28
29    Args:
30      path: the location in GS to download the file from.
31
32    Returns:
33      String contents of the file downloaded.
34
35    Raises:
36      bucket_injector.NotFoundException: if the file is not found.
37    """
38    raise NotImplementedError
39
40  def UpdateFile(self, path, contents):
41    """Uploads a file to GS.
42
43    Args:
44      path: location of the file in GS to update.
45      contents: the contents of the file to be updated.
46    """
47    raise NotImplementedError
48
49  def RemoveFile(self, path):
50    """Removes a file from GS.
51
52    Args:
53      path: the location in GS to download the file from.
54    """
55    raise NotImplementedError
56
57  def FileExists(self, path):
58    """Checks if a file exists in GS.
59
60    Args:
61      path: the location in GS of the file.
62
63    Returns:
64      boolean representing whether the file exists in GS.
65    """
66    raise NotImplementedError
67
68  def GetImageURL(self, path):
69    """Gets a URL to an item in GS from its path.
70
71    Args:
72      path: the location in GS of a file.
73
74    Returns:
75      an url to a file in GS.
76
77    Raises:
78      bucket_injector.NotFoundException: if the file is not found.
79    """
80    raise NotImplementedError
81
82  def GetAllPaths(self, prefix):
83    """Gets paths to files in GS that start with a prefix.
84
85    Args:
86      prefix: the prefix to filter files in GS.
87
88    Returns:
89      a generator of paths to files in GS.
90    """
91    raise NotImplementedError
92