Add common base weigher/weigher handler for filter scheduler

Filter scheduler is being used for more than one core projects (Nova
and Cinder as of writing), the implementation shared a lot of common
code. This patch is to move base weigher (weighing function), weigher
handler for filter scheduler into oslo to reduce possible porting.

implement bp: common-weights

Change-Id: I2d1b37438663b53e035cc262875a283e5e2ee970

1 files changed, 45 insertions, 0 deletions

diff --git a/openstack/common/scheduler/weights/__init__.py b/openstack/common/scheduler/weights/__init__.py
new file mode 100644
index 0000000..476ff8c
--- /dev/null
+++ b/openstack/common/scheduler/weights/__init__.py
@@ -0,0 +1,45 @@
+# Copyright (c) 2011 OpenStack, LLC.
+# All Rights Reserved.
+#
+#    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.
+
+"""
+Scheduler host weights
+"""
+
+
+from openstack.common.scheduler import weight
+
+
+class WeighedHost(weight.WeighedObject):
+    def to_dict(self):
+        return {
+            'weight': self.weight,
+            'host': self.obj.host,
+        }
+
+    def __repr__(self):
+        return ("WeighedHost [host: %s, weight: %s]" %
+                (self.obj.host, self.weight))
+
+
+class BaseHostWeigher(weight.BaseWeigher):
+    """Base class for host weights."""
+    pass
+
+
+class HostWeightHandler(weight.BaseWeightHandler):
+    object_class = WeighedHost
+
+    def __init__(self, namespace):
+        super(HostWeightHandler, self).__init__(BaseHostWeigher, namespace)