[Findit] Factoring the gitiles (etc) stuff out into its own directory

appengine/findit/lib/gitiles/cache_decorator.py

 # Copyright 2015 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.
 
+# TODO(wrengr): this is the only file in the findit/repository directory
+# that depends on appengine, and the only thing that depends on this
+# file is git_repository.py. Ideally we want to break that dependency
+# by offering a non-cached version of GitRepository as part of the core
+# library, with the cached version as a subclass in some appengine_utils

[stgao, 2016/10/28 18:21:00]

This is a good idea.

[wrengr, 2016/10/28 19:24:48]

Filed a bug: http://crbug.com/660466

+# directory. (This is an example of why all the Findit-as-a-library's
+# clients shoudln't be put in a directory called "handlers", since this
+# file isn't a handler.

[stgao, 2016/10/28 18:21:00]

Hm, I don't quite understand this though. Mind elaborating a little bit?

[wrengr, 2016/10/28 19:24:48]

This was addressing some previous discussions about the reorg; which I think
shouldn't be in question anymore. At that point, rather than putting all the
stuff into /services (as in the current proposal for code reorg) you'd wanted to
put everything into /handlers. But cache decorators don't handle requests from
the web app frontend, so that doesn't make sense as a place for this file to
live.

I've removed the parenthetical, as it's no longer relevant.

+
 """This module provides a decorator to cache the results of a function.
 
   Examples:
   1. Decorate a function:
     @cache_decorator.Cached()
     def Test(a):
       return a + a
 
     Test('a')
     Test('a')  # Returns the cached 'aa'.
@@ skipping 204 matching lines @@
         except Exception:  # pragma: no cover.
           logging.exception(
               'Failed to cache data for function %s.%s, args=%s, kwargs=%s',
               func.__module__, func.__name__, repr(args), repr(kwargs))
 
       return result
 
     return Wrapped
 
   return Decorator