Docserver: Add commit history and _reset_commit servlet

chrome/common/extensions/docs/server2/handler.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 time
 
 from appengine_wrappers import taskqueue
 from commit_tracker import CommitTracker
 from cron_servlet import CronServlet
 from instance_servlet import InstanceServlet
@@ skipping 42 matching lines @@
   '''
   def __init__(self, request):
     Servlet.__init__(self, request)
 
   def Get(self):
     object_store_creator = ObjectStoreCreator(start_empty=False)
     commit_tracker = CommitTracker(object_store_creator)
     return Response.Ok(commit_tracker.Get(self._request.path).Get())
 
 
+class _ResetCommitServlet(Servlet):
+  '''Writes a new commit ID to the commit cache. For example:
+
+  /_reset_commit/master/123456
+
+  will reset the 'master' commit ID to '123456'.
+  '''
+  def __init__(self, request):
+    Servlet.__init__(self, request)
+
+  def Get(self):
+    object_store_creator = ObjectStoreCreator(start_empty=False)
+    commit_tracker = CommitTracker(object_store_creator)
+    commit_name, commit_id = self._request.path.split('/')

[not at google - send to devlin, 2014/11/18 23:05:48]

Is there some kind of validation that you can do on the commit ID? It's pretty
scary just allowing the commit ID to be set arbitrarily.

+    commit_tracker.Set(commit_name, commit_id).Get()
+    return Response.Ok('Done.')
+
+
 _SERVLETS = {
   'cron': CronServlet,
   'enqueue': _EnqueueServlet,
   'patch': PatchServlet,
   'query_commit': _QueryCommitServlet,
   'refresh': RefreshServlet,
+  'reset_commit': _ResetCommitServlet,
   'test': TestServlet,
 }
 
 
 class Handler(Servlet):
   def Get(self):
     path = self._request.path
 
     if path.startswith('_'):
       servlet_path = path[1:]
       if not '/' in servlet_path:
         servlet_path += '/'
       servlet_name, servlet_path = servlet_path.split('/', 1)
       servlet = _SERVLETS.get(servlet_name)
       if servlet is None:
         return Response.NotFound('"%s" servlet not found' %  servlet_path)
     else:
       servlet_path = path
       servlet = _DEFAULT_SERVLET
 
     return servlet(Request(servlet_path,
                            self._request.host,
                            self._request.headers,
                            self._request.arguments)).Get()