Docserver: Persist stat cache for versioned file systems

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

Index: chrome/common/extensions/docs/server2/instance_servlet.py
diff --git a/chrome/common/extensions/docs/server2/instance_servlet.py b/chrome/common/extensions/docs/server2/instance_servlet.py
index 015f550ce6cdabd60af2d862b8cf406f9b1193ba..482199b391f172275d4514421ec8316914820157 100644
--- a/chrome/common/extensions/docs/server2/instance_servlet.py
+++ b/chrome/common/extensions/docs/server2/instance_servlet.py
@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 from branch_utility import BranchUtility
+from commit_tracker import CommitTracker
 from compiled_file_system import CompiledFileSystem
 from environment import IsDevServer, IsReleaseServer
 from github_file_system_provider import GithubFileSystemProvider
@@ -13,6 +14,7 @@ from object_store_creator import ObjectStoreCreator
 from server_instance import ServerInstance
 from gcs_file_system_provider import CloudStorageFileSystemProvider
 
+
 class InstanceServletRenderServletDelegate(RenderServlet.Delegate):
   '''AppEngine instances should never need to call out to Gitiles. That should
   only ever be done by the cronjobs, which then write the result into
@@ -35,13 +37,16 @@ class InstanceServletRenderServletDelegate(RenderServlet.Delegate):
   def CreateServerInstance(self):
     object_store_creator = ObjectStoreCreator(start_empty=False)
     branch_utility = self._delegate.CreateBranchUtility(object_store_creator)
+    commit_tracker = CommitTracker(object_store_creator)
     # In production have offline=True so that we can catch cron errors. In
     # development it's annoying to have to run the cron job, so offline=False.
     # Note that offline=True if running on any appengine server due to
     # http://crbug.com/345361.
     host_file_system_provider = self._delegate.CreateHostFileSystemProvider(
         object_store_creator,
-        offline=not (IsDevServer() or IsReleaseServer()))
+        offline=not (IsDevServer() or IsReleaseServer()),
+        pinned_commit=commit_tracker.Get('master').Get(),
+        cache_only=True)
     github_file_system_provider = self._delegate.CreateGithubFileSystemProvider(
         object_store_creator)
     return ServerInstance(object_store_creator,