chrome/common/extensions/docs/server2/gcs_file_system_provider.py

   1 # Copyright 2014 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 import os
   6 import environment
   7 import logging
   8
   9 from caching_file_system import CachingFileSystem
  10 from empty_dir_file_system import EmptyDirFileSystem
  11 from environment import IsTest
  12 from extensions_paths import LOCAL_GCS_DIR, LOCAL_GCS_DEBUG_CONF
  13 from gcs_file_system import CloudStorageFileSystem
  14 from local_file_system import LocalFileSystem
  15 from path_util import ToDirectory
  16
  17
  18 class CloudStorageFileSystemProvider(object):
  19   '''Provides CloudStorageFileSystem bound to a GCS bucket.
  20   '''
  21   def __init__(self, object_store_creator):
  22     self._object_store_creator = object_store_creator
  23
  24   def Create(self, bucket):
  25     '''Creates a CloudStorageFileSystemProvider.
  26
  27     |bucket| is the name of GCS bucket, eg devtools-docs. It is expected
  28              that this bucket has Read permission for this app in its ACLs.
  29
  30     Optional configuration can be set in a local_debug/gcs_debug.conf file:
  31       use_local_fs=True|False
  32       remote_bucket_prefix=<prefix>
  33
  34     If running in Preview mode or in Development mode with use_local_fs set to
  35     True, buckets and files are looked for inside the local_debug folder instead
  36     of in the real GCS server.
  37     '''
  38     if IsTest():
  39       return EmptyDirFileSystem()
  40
  41     debug_bucket_prefix = None
  42     use_local_fs = False
  43     if os.path.exists(LOCAL_GCS_DEBUG_CONF):
  44       with open(LOCAL_GCS_DEBUG_CONF, "r") as token_file:
  45         properties = dict(line.strip().split('=', 1) for line in token_file)
  46       use_local_fs = properties.get('use_local_fs', 'False')=='True'
  47       debug_bucket_prefix = properties.get('remote_bucket_prefix', None)
  48       logging.debug('gcs: prefixing all bucket names with %s' %
  49                     debug_bucket_prefix)
  50
  51     if use_local_fs:
  52       return LocalFileSystem(ToDirectory(os.path.join(LOCAL_GCS_DIR, bucket)))
  53
  54     if debug_bucket_prefix:
  55       bucket = debug_bucket_prefix + bucket
  56
  57     return CachingFileSystem(CloudStorageFileSystem(bucket),
  58                              self._object_store_creator)
  59
  60   @staticmethod
  61   def ForEmpty():
  62     class EmptyImpl(object):
  63       def Create(self, bucket):
  64         return EmptyDirFileSystem()
  65     return EmptyImpl()