Move CooldownMixin into separate file

CooldownMixin is a class that can be shared between OS and AWS
auto-scaling implementations.  This patch moves it to a shared
subdirectory.

Implements: partial-blueprint reorg-asg-code
Change-Id: I40e470460e84944d317f5b1772fc562abf62896d

heat/engine/resources/autoscaling.py

@@ -31,7 +31,7 @@ from heat.engine import signal_responder
 from heat.engine import stack_resource
 from heat.openstack.common import excutils
 from heat.openstack.common import log as logging
-from heat.openstack.common import timeutils
+from heat.scaling import cooldown
 from heat.scaling import template
 
 LOG = logging.getLogger(__name__)
@@ -44,36 +44,6 @@ LOG = logging.getLogger(__name__)
     'ExactCapacity', 'ChangeInCapacity', 'PercentChangeInCapacity')
 
 
-class CooldownMixin(object):
-    '''
-    Utility class to encapsulate Cooldown related logic which is shared
-    between AutoScalingGroup and ScalingPolicy
-    '''
-    def _cooldown_inprogress(self):
-        inprogress = False
-        try:
-            # Negative values don't make sense, so they are clamped to zero
-            cooldown = max(0, self.properties[self.COOLDOWN])
-        except TypeError:
-            # If not specified, it will be None, same as cooldown == 0
-            cooldown = 0
-
-        metadata = self.metadata_get()
-        if metadata and cooldown != 0:
-            last_adjust = metadata.keys()[0]
-            if not timeutils.is_older_than(last_adjust, cooldown):
-                inprogress = True
-        return inprogress
-
-    def _cooldown_timestamp(self, reason):
-        # Save resource metadata with a timestamp and reason
-        # If we wanted to implement the AutoScaling API like AWS does,
-        # we could maintain event history here, but since we only need
-        # the latest event for cooldown, just store that for now
-        metadata = {timeutils.strtime(): reason}
-        self.metadata_set(metadata)
-
-
 def _calculate_new_capacity(current, adjustment, adjustment_type,
                             minimum, maximum):
     """
@@ -473,7 +443,7 @@ class InstanceGroup(stack_resource.StackResource):
         return self._environment()
 
 
-class AutoScalingGroup(InstanceGroup, CooldownMixin):
+class AutoScalingGroup(InstanceGroup, cooldown.CooldownMixin):
 
     PROPERTIES = (
         AVAILABILITY_ZONES, LAUNCH_CONFIGURATION_NAME, MAX_SIZE, MIN_SIZE,
@@ -946,7 +916,7 @@ class AutoScalingResourceGroup(AutoScalingGroup):
                                             template_version=template_version)
 
 
-class ScalingPolicy(signal_responder.SignalResponder, CooldownMixin):
+class ScalingPolicy(signal_responder.SignalResponder, cooldown.CooldownMixin):
     PROPERTIES = (
         AUTO_SCALING_GROUP_NAME, SCALING_ADJUSTMENT, ADJUSTMENT_TYPE,
         COOLDOWN,

heat/scaling/cooldown.py

@@ -0,0 +1,44 @@
+#
+#    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.
+
+from heat.openstack.common import timeutils
+
+
+class CooldownMixin(object):
+    '''
+    Utility class to encapsulate Cooldown related logic which is shared
+    between AutoScalingGroup and ScalingPolicy
+    '''
+    def _cooldown_inprogress(self):
+        inprogress = False
+        try:
+            # Negative values don't make sense, so they are clamped to zero
+            cooldown = max(0, self.properties[self.COOLDOWN])
+        except TypeError:
+            # If not specified, it will be None, same as cooldown == 0
+            cooldown = 0
+
+        metadata = self.metadata_get()
+        if metadata and cooldown != 0:
+            last_adjust = metadata.keys()[0]
+            if not timeutils.is_older_than(last_adjust, cooldown):
+                inprogress = True
+        return inprogress
+
+    def _cooldown_timestamp(self, reason):
+        # Save resource metadata with a timestamp and reason
+        # If we wanted to implement the AutoScaling API like AWS does,
+        # we could maintain event history here, but since we only need
+        # the latest event for cooldown, just store that for now
+        metadata = {timeutils.strtime(): reason}
+        self.metadata_set(metadata)