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 import posixpath 6 7 from docs_server_utils import StringIdentity 8 from file_system import FileSystem 9 from future import Future 10 11 12 class ChrootFileSystem(FileSystem): 13 '''ChrootFileSystem(fs, path) exposes a FileSystem whose root is |path| inside 14 |fs|, so ChrootFileSystem(fs, 'hello').Read(['world']) is equivalent to 15 fs.Read(['hello/world']) with the 'hello' prefix stripped from the result. 16 ''' 17 18 def __init__(self, file_system, root): 19 '''Parameters: 20 |file_system| The FileSystem instance to transpose paths of. 21 |root| The path to transpose all Read/Stat calls by. 22 ''' 23 self._file_system = file_system 24 self._root = root.strip('/') 25 26 def Read(self, paths, skip_not_found=False): 27 # Maintain reverse mapping so the result can be mapped to the original 28 # paths given (the result from |file_system| will include |root| in the 29 # result, which would be wrong). 30 prefixed_paths = {} 31 def prefix(path): 32 prefixed = posixpath.join(self._root, path) 33 prefixed_paths[prefixed] = path 34 return prefixed 35 def next(results): 36 return dict((prefixed_paths[path], content) 37 for path, content in results.iteritems()) 38 return self._file_system.Read(tuple(prefix(path) for path in paths), 39 skip_not_found-skip_not_found).Then(next) 40 41 def Refresh(self): 42 return self._file_system.Refresh() 43 44 def Stat(self, path): 45 return self._file_system.Stat(posixpath.join(self._root, path)) 46 47 def GetIdentity(self): 48 return StringIdentity( 49 '%s/%s' % (self._file_system.GetIdentity(), self._root)) 50 51 def __repr__(self): 52 return 'ChrootFileSystem(%s, %s)' % ( 53 self._root, repr(self._file_system)) 54
