Ruslan Kamaldinov 8e6a40e647 Initial MuranoPL implementation v2
Moved rest of DSL PoC to the main repo.

Change-Id: Ic4f28b316736c12c3af321ff57d4d1d139dbfe36
Partially-Implements: blueprint new-metadata-dsl
2014-03-18 12:41:41 +04:00

222 lines
8.6 KiB
Python

# Copyright (c) 2014 Mirantis, Inc.
#
# 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.
import functools
import inspect
import types
import uuid
import eventlet
from eventlet import event as e_event
from yaql import context as y_context
from muranoapi.engine import attribute_store as attr_store
from muranoapi.engine import exceptions
from muranoapi.engine import expressions
from muranoapi.engine import helpers
from muranoapi.engine import object_store
from muranoapi.engine import objects
from muranoapi.engine import yaql_functions
class MuranoDslExecutor(object):
def __init__(self, class_loader, environment=None):
self._class_loader = class_loader
self._object_store = object_store.ObjectStore(class_loader)
self._attribute_store = attr_store.AttributeStore()
self._root_context = class_loader.create_root_context()
self._root_context.set_data(self, '?executor')
self._root_context.set_data(self._class_loader, '?classLoader')
self._root_context.set_data(environment, '?environment')
self._root_context.set_data(self._object_store, '?objectStore')
self._root_context.set_data(self._attribute_store, '?attributeStore')
self._locks = {}
yaql_functions.register(self._root_context)
self._root_context = y_context.Context(self._root_context)
@property
def object_store(self):
return self._object_store
@property
def attribute_store(self):
return self._attribute_store
def to_yaql_args(self, args):
if not args:
return tuple()
elif isinstance(args, types.TupleType):
return args
elif isinstance(args, types.ListType):
return tuple(args)
elif isinstance(args, types.DictionaryType):
return tuple(args.items())
else:
raise ValueError()
def invoke_method(self, name, this, context, murano_class, *args):
if context is None:
context = self._root_context
implementations = this.type.find_method(name)
delegates = []
for declaring_class, name in implementations:
method = declaring_class.get_method(name)
if not method:
continue
arguments_scheme = method.arguments_scheme
try:
try:
params = self._evaluate_parameters(
arguments_scheme, context, this, *args)
except Exception:
# TODO(slagun): print exception
params = self._evaluate_parameters(
arguments_scheme, context, this, *args)
delegates.append(functools.partial(
self._invoke_method_implementation,
method, this, declaring_class, context, params))
except TypeError:
continue
if len(delegates) < 1:
raise exceptions.NoMethodFound(name)
elif len(delegates) > 1:
raise exceptions.AmbiguousMethodName(name)
else:
return delegates[0]()
def _invoke_method_implementation(self, method, this, murano_class,
context, params):
body = method.body
if not body:
return None
current_thread = eventlet.greenthread.getcurrent()
if not hasattr(current_thread, '_murano_dsl_thread_marker'):
thread_marker = current_thread._murano_dsl_thread_marker = \
uuid.uuid4().hex
else:
thread_marker = current_thread._murano_dsl_thread_marker
method_id = id(body)
this_id = this.object_id
event, marker = self._locks.get((method_id, this_id), (None, None))
if event:
if marker == thread_marker:
return self._invoke_method_implementation_gt(
body, this, params, murano_class, context)
event.wait()
event = e_event.Event()
self._locks[(method_id, this_id)] = (event, thread_marker)
gt = eventlet.spawn(self._invoke_method_implementation_gt, body,
this, params, murano_class, context,
thread_marker)
result = gt.wait()
del self._locks[(method_id, this_id)]
event.send()
return result
def _invoke_method_implementation_gt(self, body, this,
params, murano_class, context,
thread_marker=None):
if thread_marker:
current_thread = eventlet.greenthread.getcurrent()
current_thread._murano_dsl_thread_marker = thread_marker
if callable(body):
if '_context' in inspect.getargspec(body).args:
params['_context'] = self._create_context(
this, murano_class, context, **params)
if inspect.ismethod(body) and not body.__self__:
return body(this, **params)
else:
return body(**params)
elif isinstance(body, expressions.DslExpression):
return self.execute(body, murano_class, this, context, **params)
else:
raise ValueError()
def _evaluate_parameters(self, arguments_scheme, context, this, *args):
arg_names = list(arguments_scheme.keys())
parameter_values = {}
i = 0
for arg in args:
value = helpers.evaluate(arg, context)
if isinstance(value, types.TupleType) and len(value) == 2 and \
isinstance(value[0], types.StringTypes):
name = value[0]
value = value[1]
if name not in arguments_scheme:
raise TypeError()
else:
if i >= len(arg_names):
raise TypeError()
name = arg_names[i]
i += 1
if callable(value):
value = value()
arg_spec = arguments_scheme[name]
parameter_values[name] = arg_spec.validate(
value, this, self._root_context, self._object_store)
for name, arg_spec in arguments_scheme.iteritems():
if name not in parameter_values:
if not arg_spec.has_default:
raise TypeError()
parameter_values[name] = arg_spec.validate(
helpers.evaluate(arg_spec.default, context),
this, self._root_context, self._object_store)
return parameter_values
def _create_context(self, this, murano_class, context, **kwargs):
new_context = self._class_loader.create_local_context(
parent_context=self._root_context,
murano_class=murano_class)
new_context.set_data(this)
new_context.set_data(this, 'this')
new_context.set_data(this, '?this')
new_context.set_data(murano_class, '?type')
new_context.set_data(context, '?callerContext')
@y_context.EvalArg('obj', arg_type=objects.MuranoObject)
@y_context.EvalArg('property_name', arg_type=str)
def obj_attribution(obj, property_name):
return obj.get_property(property_name, murano_class)
@y_context.EvalArg('prefix', str)
@y_context.EvalArg('name', str)
def validate(prefix, name):
return murano_class.namespace_resolver.resolve_name(
'%s:%s' % (prefix, name))
new_context.register_function(obj_attribution, '#operator_.')
new_context.register_function(validate, '#validate')
for key, value in kwargs.iteritems():
new_context.set_data(value, key)
return new_context
def execute(self, expression, murano_class, this, context, **kwargs):
new_context = self._create_context(
this, murano_class, context, **kwargs)
return expression.execute(new_context, murano_class)
def load(self, data):
if not isinstance(data, types.DictionaryType):
raise TypeError()
self._attribute_store.load(data.get('Attributes') or [])
return self._object_store.load(data.get('Objects') or {},
None, self._root_context)