Docserver: Persist stat cache for versioned file systems

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

Index: chrome/common/extensions/docs/server2/commit_tracker.py
diff --git a/chrome/common/extensions/docs/server2/commit_tracker.py b/chrome/common/extensions/docs/server2/commit_tracker.py
new file mode 100644
index 0000000000000000000000000000000000000000..8871a61bb0e45bdcf7dd681de6bbe2b02cbc54f5
--- /dev/null
+++ b/chrome/common/extensions/docs/server2/commit_tracker.py
@@ -0,0 +1,20 @@
+# Copyright 2014 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.
+
+from object_store_creator import ObjectStoreCreator
+from future import Future
+
+
+class CommitTracker(object):
+  '''Utility class for managing and querying the storage of various named commit
+  IDs.'''
+  def __init__(self, object_store_creator):
+    self._store = object_store_creator.Create(str, category='commits',

[not at google - send to devlin, 2014/10/24 00:04:50]

s/str/CommitTracker/ ?
Also it wouldn't need a category then, but, I guess it can't hurt.
Also perhaps explain why you need (to override) the start_empty.

[Ken Rockot(use gerrit already), 2014/10/24 21:26:53]

Oh. Epiphany. I was making incorrect assumptions about the implications of the
class name v.s. category name. In retrospect those assumptions are nonsensical.
But I get it now, and it's much simpler than I expected. :D

+        start_empty=False)
+
+  def Get(self, key):
+    return self._store.Get(key)
+
+  def Set(self, key, commit):
+    return self._store.Set(key, commit)