Docserver: Override Walk in CachingFileSystem

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

 # Copyright (c) 2012 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.
 
 import copy
 import logging
 import posixpath
 
-from compiled_file_system import SingleFile, Unicode
+from compiled_file_system import Cache, SingleFile, Unicode
 from data_source import DataSource
 from extensions_paths import JSON_TEMPLATES
 from future import Future
 from third_party.json_schema_compiler.json_parse import Parse
 
 
 def _AddLevels(items, level):
   '''Add a 'level' key to each item in |items|. 'level' corresponds to how deep
   in |items| an item is. |level| sets the starting depth.
   '''
@@ skipping 38 matching lines @@
   navigation bar.
   '''
   def __init__(self, server_instance, request):
     self._cache = server_instance.compiled_fs_factory.Create(
         server_instance.host_file_system_provider.GetTrunk(),
         self._CreateSidenavDict,
         SidenavDataSource)
     self._server_instance = server_instance
     self._request = request
 
+  @Cache

[not at google - send to devlin, 2014/08/29 05:00:14]

Why this in particular?

[ahernandez, 2014/08/29 17:20:00]

The test for this is expecting cached data, and I thought it would be easier to
keep caching assumptions the same in this CL, then in another we can cache less.

   @SingleFile
   @Unicode
   def _CreateSidenavDict(self, _, content):
     items = Parse(content)
     # Start at level 2, the top <ul> element is level 1.
     _AddLevels(items, level=2)
     self._QualifyHrefs(items)
     return items
 
   def _QualifyHrefs(self, items):
@@ skipping 19 matching lines @@
 
   def get(self, key):
     # TODO(mangini/kalman): Use |key| to decide which sidenav to use,
     # which will require a more complex Cron method.
     sidenav = self._cache.GetFromFile(
         posixpath.join(JSON_TEMPLATES, 'chrome_sidenav.json')).Get()
     sidenav = copy.deepcopy(sidenav)
     _AddAnnotations(sidenav,
                     self._server_instance.base_path + self._request.path)
     return sidenav