Implement caching of resource attributes

The default caching mode cache_local will return the previously
resolved value if it is available.

Whenever any resource changes state, all resource attribute caches
are cleared just in case the state change has side-effects in
other resources.

The caching mode cache_none performs no caching, and is chosen
for attributes which are one of the following:
* Derived from any resource's metadata, resource data or resource_id
* An API call which returns a secret

Caching currently only exists for the duration of the parser.Stack
object, but there is future potential for a caching mode which
caches attributes spanning multiple requests.

Closes-Bug: #1321970

Change-Id: I01bf2983b726f0e81a2b8d5be94627353bdeb406
changes/55/94755/2
Steve Baker 8 years ago
parent 7047425666
commit ab412fee30
  1. 3
      contrib/marconi/marconi/resources/queue.py
  2. 6
      contrib/rackspace/rackspace/resources/auto_scale.py
  3. 3
      contrib/rackspace/rackspace/resources/cloud_server.py
  4. 31
      heat/engine/attributes.py
  5. 9
      heat/engine/parser.py
  6. 2
      heat/engine/resource.py
  7. 3
      heat/engine/resources/nova_keypair.py
  8. 3
      heat/engine/resources/random_string.py
  9. 6
      heat/engine/resources/user.py
  10. 3
      heat/engine/resources/wait_condition.py
  11. 29
      heat/tests/test_attributes.py

@ -57,7 +57,8 @@ class MarconiQueue(resource.Resource):
attributes_schema = {
QUEUE_ID: attributes.Schema(
_("ID of the queue.")
_("ID of the queue."),
cache_mode=attributes.Schema.CACHE_NONE
),
HREF: attributes.Schema(
_("The resource href of the queue.")

@ -513,10 +513,12 @@ class WebHook(resource.Resource):
attributes_schema = {
EXECUTE_URL: attributes.Schema(
_("The url for executing the webhook (requires auth).")
_("The url for executing the webhook (requires auth)."),
cache_mode=attributes.Schema.CACHE_NONE
),
CAPABILITY_URL: attributes.Schema(
_("The url for executing the webhook (doesn't require auth).")
_("The url for executing the webhook (doesn't require auth)."),
cache_mode=attributes.Schema.CACHE_NONE
),
}

@ -79,7 +79,8 @@ class CloudServer(server.Server):
_('The private IPv4 address of the server.')
),
ADMIN_PASS_ATTR: attributes.Schema(
_('The administrator password for the server.')
_('The administrator password for the server.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}
)

@ -32,10 +32,20 @@ class Schema(constr.Schema):
'description',
)
CACHE_MODES = (
CACHE_LOCAL,
CACHE_NONE
) = (
'cache_local',
'cache_none'
)
def __init__(self, description=None,
support_status=support.SupportStatus()):
support_status=support.SupportStatus(),
cache_mode=CACHE_LOCAL):
self.description = description
self.support_status = support_status
self.cache_mode = cache_mode
def __getitem__(self, key):
if key == self.DESCRIPTION:
@ -104,6 +114,10 @@ class Attributes(collections.Mapping):
self._resource_name = res_name
self._resolver = resolver
self._attributes = Attributes._make_attributes(schema)
self.reset_resolved_values()
def reset_resolved_values(self):
self._resolved_values = {}
@staticmethod
def _make_attributes(schema):
@ -133,7 +147,20 @@ class Attributes(collections.Mapping):
if key not in self:
raise KeyError(_('%(resource)s: Invalid attribute %(key)s') %
dict(resource=self._resource_name, key=key))
return self._resolver(key)
attrib = self._attributes.get(key)
if attrib.schema.cache_mode == Schema.CACHE_NONE:
return self._resolver(key)
if key in self._resolved_values:
return self._resolved_values[key]
value = self._resolver(key)
if value is not None:
# only store if not None, it may resolve to an actual value
# on subsequent calls
self._resolved_values[key] = value
return value
def __len__(self):
return len(self._attributes)

@ -862,3 +862,12 @@ class Stack(collections.Mapping):
'Use heat.engine.function.resolve() instead',
DeprecationWarning)
return function.resolve(snippet)
def reset_resource_attributes(self):
# nothing is cached if no resources exist
if not self._resources:
return
# a change in some resource may have side-effects in the attributes
# of other resources, so ensure that attributes are re-calculated
for res in self.resources.itervalues():
res.attributes.reset_resolved_values()

@ -796,6 +796,8 @@ class Resource(object):
if new_state != old_state:
self._add_event(action, status, reason)
self.stack.reset_resource_attributes()
@property
def state(self):
'''Returns state, tuple of action, status.'''

@ -73,7 +73,8 @@ class KeyPair(resource.Resource):
_('The public key.')
),
PRIVATE_KEY: attributes.Schema(
_('The private key if it has been saved.')
_('The private key if it has been saved.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}

@ -71,7 +71,8 @@ class RandomString(resource.Resource):
attributes_schema = {
VALUE: attributes.Schema(
_('The random string generated by this resource. This value is '
'also available by referencing the resource.')
'also available by referencing the resource.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}

@ -160,10 +160,12 @@ class AccessKey(resource.Resource):
attributes_schema = {
USER_NAME: attributes.Schema(
_('Username associated with the AccessKey.')
_('Username associated with the AccessKey.'),
cache_mode=attributes.Schema.CACHE_NONE
),
SECRET_ACCESS_KEY: attributes.Schema(
_('Keypair secret key.')
_('Keypair secret key.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}

@ -187,7 +187,8 @@ class WaitCondition(resource.Resource):
attributes_schema = {
DATA: attributes.Schema(
_('JSON serialized dict containing data associated with wait '
'condition signals sent to the handle.')
'condition signals sent to the handle.'),
cache_mode=attributes.Schema.CACHE_NONE
),
}

@ -86,7 +86,9 @@ class AttributesTest(common.HeatTestCase):
attributes_schema = {
"test1": attributes.Schema("Test attrib 1"),
"test2": attributes.Schema("Test attrib 2"),
"test3": attributes.Schema("Test attrib 3"),
"test3": attributes.Schema(
"Test attrib 3",
cache_mode=attributes.Schema.CACHE_NONE)
}
def setUp(self):
@ -147,3 +149,28 @@ class AttributesTest(common.HeatTestCase):
expected,
attributes.Attributes.as_outputs("test_resource",
MyTestResourceClass))
def test_caching_local(self):
value = 'value1'
test_resolver = lambda x: value
self.m.ReplayAll()
attribs = attributes.Attributes('test resource',
self.attributes_schema,
test_resolver)
self.assertEqual("value1", attribs['test1'])
value = 'value1 changed'
self.assertEqual("value1", attribs['test1'])
attribs.reset_resolved_values()
self.assertEqual("value1 changed", attribs['test1'])
def test_caching_none(self):
value = 'value3'
test_resolver = lambda x: value
self.m.ReplayAll()
attribs = attributes.Attributes('test resource',
self.attributes_schema,
test_resolver)
self.assertEqual("value3", attribs['test3'])
value = 'value3 changed'
self.assertEqual("value3 changed", attribs['test3'])

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