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..0247269eaba2b84bdd40c86e1e1cbf4741291ab3 100644
--- a/chrome/common/extensions/docs/server2/instance_servlet.py
+++ b/chrome/common/extensions/docs/server2/instance_servlet.py
@@ -13,6 +13,17 @@ from object_store_creator import ObjectStoreCreator
 from server_instance import ServerInstance
 from gcs_file_system_provider import CloudStorageFileSystemProvider
 
+
+
+def _GetInstanceMasterCommit():

[not at google - send to devlin, 2014/10/20 21:06:57]

Comment.

[Ken Rockot(use gerrit already), 2014/10/22 03:19:54]

Done.

+  creator = ObjectStoreCreator(start_empty=False)
+  store = creator.Create(str, category='commits')

[not at google - send to devlin, 2014/10/20 21:06:57]

Use InstanceServlet rather than str?

Also you might as well re-use the ObjectStoreCreator that you created in
CreateServerInstance?

[Ken Rockot(use gerrit already), 2014/10/22 03:19:54]

Done.

+  def get_master(results):
+    return results.get('master')
+  return store.GetMulti(['master']).Then(get_master).Get()

[not at google - send to devlin, 2014/10/20 21:06:57]

You could just return store.Get('master').Get()?

[Ken Rockot(use gerrit already), 2014/10/22 03:19:54]

Oh. Derp. Didn't actually look at the base ObjectStore interface. Done.

+
+

[not at google - send to devlin, 2014/10/20 21:06:57]

dd

+
 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
@@ -41,7 +52,9 @@ class InstanceServletRenderServletDelegate(RenderServlet.Delegate):
     # 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=_GetInstanceMasterCommit(),
+        cache_only=True)
     github_file_system_provider = self._delegate.CreateGithubFileSystemProvider(
         object_store_creator)
     return ServerInstance(object_store_creator,