Added query caching
authorSverre Rabbelier <srabbelier@gmail.com>
Wed, 11 Mar 2009 21:28:11 +0000
changeset 1795 336c35c82b87
parent 1794 6ffd25bedef9
child 1796 5cd78a7aacdd
Added query caching Patch by: Sverre Rabbelier
app/soc/cache/logic.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/soc/cache/logic.py	Wed Mar 11 21:28:11 2009 +0000
@@ -0,0 +1,68 @@
+#!/usr/bin/python2.5
+#
+# Copyright 2009 the Melange authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Module contains logic memcaching functions.
+"""
+
+__authors__ = [
+    '"Sverre Rabbelier" <sverre@rabbelier.nl>',
+  ]
+
+
+from google.appengine.api import memcache
+
+import soc.cache.base
+
+
+def key(model, filter):
+  """Returns the memcache key for this query.
+  """
+
+  return 'query_for_%s_%s' % (repr(model.kind()), repr(filter))
+
+
+def get(model, filter, *args, **kwargs):
+  """Retrieves the data for the specified query from the memcache.
+  """
+
+  memcache_key = key(model, filter)
+  import logging; logging.info(memcache_key)
+  return memcache.get(memcache_key), memcache_key
+
+
+def put(data, memcache_key, *args, **kwargs):
+  """Sets the data for the specified query in the memcache.
+
+  Args:
+    data: the data to be cached
+  """
+
+  # Store data for fifteen minutes to force a refresh every so often
+  retention = 15*60
+
+  memcache.add(memcache_key, data, retention)
+
+
+def flush(model, filter):
+  """Removes the data for the current user from the memcache.
+  """
+
+  memcache_key = key(model, filter)
+  memcache.delete(memcache_key)
+
+
+# define the cache function
+cache = soc.cache.base.getCacher(get, put)