Refactor the devserver to make it easier to control caching

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

+# Copyright 2013 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 in_memory_object_store import InMemoryObjectStore
+from memcache_object_store import MemcacheObjectStore
+
+class ObjectStoreCreator(object):
+  def __init__(self, cls, store_type=None):
+    '''Creates stores with a top-level namespace given by the name of |cls|.
+    Set an explicit |store_type| if necessary for tests.
+
+    By convention this should be the name of the class which owns the object
+    store. If a class needs multiple object store it should use Create with the
+    |category| argument.
+    '''
+    assert isinstance(cls, type)
+    assert not cls.__name__[0].islower()  # guard against non-class types
+    self._name = cls.__name__
+    self._store_type = store_type
+
+  def Create(self, version=None, category=None):
+    '''Creates a new object store with the top namespace given in the
+    constructor, at version |version|, with an optional |category| for classes
+    that need multiple object stores (e.g. one for stat and one for read).
+    '''
+    namespace = self._name
+    if category is not None:
+      assert not any(c.isdigit() for c in category)
+      namespace = '%s/%s' % (namespace, category)
+    if version is not None:
+      assert isinstance(version, int)
+      namespace = '%s/%s' % (namespace, version)
+    if self._store_type is not None:
+      return self._store_type(namespace)
+    return InMemoryObjectStore(MemcacheObjectStore(namespace))