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

   1 # Copyright (c) 2012 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 sys
   7
   8 from docs_server_utils import StringIdentity
   9 from file_system import FileSystem, FileNotFoundError, StatInfo
  10 from future import Gettable, Future
  11
  12 def _ConvertToFilepath(path):
  13   return path.replace('/', os.sep)
  14
  15 def _ConvertFromFilepath(path):
  16   return path.replace(os.sep, '/')
  17
  18 def _ReadFile(filename):
  19   try:
  20     with open(filename, 'rb') as f:
  21       return f.read()
  22   except IOError as e:
  23     raise FileNotFoundError('Read failed for %s: %s' % (filename, e))
  24
  25 def _ListDir(dir_name):
  26   all_files = []
  27   try:
  28     files = os.listdir(dir_name)
  29   except OSError as e:
  30     raise FileNotFoundError('os.listdir failed for %s: %s' % (dir_name, e))
  31   for os_path in files:
  32     posix_path = _ConvertFromFilepath(os_path)
  33     if os_path.startswith('.'):
  34       continue
  35     if os.path.isdir(os.path.join(dir_name, os_path)):
  36       all_files.append(posix_path + '/')
  37     else:
  38       all_files.append(posix_path)
  39   return all_files
  40
  41 def _CreateStatInfo(path):
  42   try:
  43     path_mtime = os.stat(path).st_mtime
  44     if os.path.isdir(path):
  45       child_versions = dict((_ConvertFromFilepath(filename),
  46                              os.stat(os.path.join(path, filename)).st_mtime)
  47           for filename in os.listdir(path))
  48       # This file system stat mimics subversion, where the stat of directories
  49       # is max(file stats). That means we need to recursively check the whole
  50       # file system tree :\ so approximate that by just checking this dir.
  51       version = max([path_mtime] + child_versions.values())
  52     else:
  53       child_versions = None
  54       version = path_mtime
  55     return StatInfo(version, child_versions)
  56   except OSError as e:
  57     raise FileNotFoundError('os.stat failed for %s: %s' % (path, e))
  58
  59 class LocalFileSystem(FileSystem):
  60   '''FileSystem implementation which fetches resources from the local
  61   filesystem.
  62   '''
  63   def __init__(self, base_path):
  64     self._base_path = _ConvertToFilepath(base_path)
  65
  66   @staticmethod
  67   def Create(root=''):
  68     return LocalFileSystem(
  69         os.path.join(sys.path[0], '..', '..', '..', '..', '..', root))
  70
  71   def Read(self, paths):
  72     def resolve():
  73       result = {}
  74       for path in paths:
  75         full_path = os.path.join(self._base_path,
  76                                  _ConvertToFilepath(path).lstrip(os.sep))
  77         if path == '' or path.endswith('/'):
  78           result[path] = _ListDir(full_path)
  79         else:
  80           result[path] = _ReadFile(full_path)
  81       return result
  82     return Future(delegate=Gettable(resolve))
  83
  84   def Refresh(self):
  85     return Future(value=())
  86
  87   def Stat(self, path):
  88     full_path = os.path.join(self._base_path,
  89                              _ConvertToFilepath(path).lstrip(os.sep))
  90     return _CreateStatInfo(full_path)
  91
  92   def GetIdentity(self):
  93     return '@'.join((self.__class__.__name__, StringIdentity(self._base_path)))
  94
  95   def __repr__(self):
  96     return 'LocalFileSystem(%s)' % self._base_path