Docserver: Factor SamplesModel out of SamplesDataSource

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

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from compiled_file_system import CompiledFileSystem
 from docs_server_utils import StringIdentity
 from file_system import FileNotFoundError
 from future import Future
+from path_util import ToDirectory
 
 
 class ChainedCompiledFileSystem(object):
   '''A CompiledFileSystem implementation that fetches data from a chain of
   possible FileSystems. The chain consists of some number of FileSystems which
   may have cached data for their CompiledFileSystem instances (injected on
   Factory construction) + the main FileSystem (injected at Creation time).
 
   The expected configuration is that the main FileSystem is a PatchedFileSystem
   and the chain the FileSystem which it patches, but with file systems
@@ skipping 26 matching lines @@
     self._compiled_fs_chain = compiled_fs_chain
     self._identity = identity
 
   def GetFromFile(self, path):
     return self._GetImpl(
         path,
         lambda compiled_fs: compiled_fs.GetFromFile(path),
         lambda compiled_fs: compiled_fs.GetFileVersion(path))
 
   def GetFromFileListing(self, path):
-    if not path.endswith('/'):
-      path += '/'
+    path = ToDirectory(path)
     return self._GetImpl(
         path,
         lambda compiled_fs: compiled_fs.GetFromFileListing(path),
         lambda compiled_fs: compiled_fs.GetFileListingVersion(path))
 
   def _GetImpl(self, path, reader, version_getter):
     # Strategy: Get the current version of |path| in main FileSystem, then run
     # through |_compiled_fs_chain| in *reverse* to find the "oldest" FileSystem
     # with an up-to-date version of that file.
     #
@@ skipping 17 matching lines @@
             return read_future.Get()
       except FileNotFoundError:
         pass
       # Try an arbitrary operation again to generate a realistic stack trace.
       return read_futures[0][0].Get()
 
     return Future(callback=resolve)
 
   def GetIdentity(self):
     return self._identity