Some further cleanup in the meta branch

* adds squashing to objects, which allows them to be squashed down
  to a final "view" before post_validate to avoid expensive evaluations
  of parent attributes

lib/ansible/executor/task_executor.py

@@ -72,6 +72,8 @@ class TaskExecutor:
         self._connection        = None
         self._rslt_q            = rslt_q
 
+        self._task.squash()
+
     def run(self):
         '''
         The main executor entrypoint, where we determine if the specified

lib/ansible/playbook/base.py

@@ -24,7 +24,7 @@ import itertools
 import operator
 import uuid
 
-from copy import deepcopy
+from copy import copy as shallowcopy, deepcopy
 from functools import partial
 from inspect import getmembers
 
@@ -53,8 +53,10 @@ def _generic_g(prop_name, self):
         raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, prop_name))
 
 def _generic_g_method(prop_name, self):
-    method = "_get_attr_%s" % prop_name
     try:
+        if self._squashed:
+            return self._attributes[prop_name]
+        method = "_get_attr_%s" % prop_name
         return getattr(self, method)()
     except KeyError:
         raise AttributeError("'%s' object has no attribute '%s'" % (self.__class__.__name__, prop_name))
@@ -62,7 +64,7 @@ def _generic_g_method(prop_name, self):
 def _generic_g_parent(prop_name, self):
     try:
         value = self._attributes[prop_name]
-        if value is None and not self._finalized:
+        if value is None and not self._squashed and not self._finalized:
             try:
                 value = self._get_parent_attribute(prop_name)
             except AttributeError:
@@ -106,10 +108,13 @@ class BaseMeta(type):
                     # its value from a parent object
                     method = "_get_attr_%s" % attr_name
                     if method in src_dict or method in dst_dict:
+                        #print("^ assigning generic_g_method to %s" % attr_name)
                         getter = partial(_generic_g_method, attr_name)
-                    elif ('_get_parent_attribute' in src_dict or '_get_parent_attribute' in dst_dict)  and value.inherit:
+                    elif '_get_parent_attribute' in dst_dict and value.inherit:
+                        #print("^ assigning generic_g_parent to %s" % attr_name)
                         getter = partial(_generic_g_parent, attr_name)
                     else:
+                        #print("^ assigning generic_g to %s" % attr_name)
                         getter = partial(_generic_g, attr_name)
 
                     setter = partial(_generic_s, attr_name)
@@ -135,6 +140,7 @@ class BaseMeta(type):
 
         # now create the attributes based on the FieldAttributes
         # available, including from parent (and grandparent) objects
+        #print("creating class %s" % name)
         _create_attrs(dct, dct)
         _process_parents(parents, dct)
 
@@ -148,7 +154,7 @@ class Base(with_metaclass(BaseMeta, object)):
     _remote_user         = FieldAttribute(isa='string')
 
     # variables
-    _vars                = FieldAttribute(isa='dict', priority=100)
+    _vars                = FieldAttribute(isa='dict', priority=100, inherit=False)
 
     # flags and misc. settings
     _environment         = FieldAttribute(isa='list')
@@ -173,6 +179,7 @@ class Base(with_metaclass(BaseMeta, object)):
 
         # other internal params
         self._validated = False
+        self._squashed  = False
         self._finalized = False
 
         # every object gets a random uuid:
@@ -297,6 +304,22 @@ class Base(with_metaclass(BaseMeta, object)):
 
         self._validated = True
 
+    def squash(self):
+        '''
+        Evaluates all attributes and sets them to the evaluated version,
+        so that all future accesses of attributes do not need to evaluate
+        parent attributes.
+        '''
+        if not self._squashed:
+            for name in self._valid_attrs.keys():
+                getter = partial(_generic_g, name)
+                setter = partial(_generic_s, name)
+                deleter = partial(_generic_d, name)
+
+                self._attributes[name] = getattr(self, name)
+                #print("squashed attr %s: %s" % (name, self._attributes[name]))
+            self._squashed = True
+
     def copy(self):
         '''
         Create a copy of this object and return it.
@@ -305,13 +328,7 @@ class Base(with_metaclass(BaseMeta, object)):
         new_me = self.__class__()
 
         for name in self._valid_attrs.keys():
-            attr_val = getattr(self, name)
-            if isinstance(attr_val, collections.Sequence):
-                setattr(new_me, name, attr_val[:])
-            elif isinstance(attr_val, collections.Mapping):
-                setattr(new_me, name, attr_val.copy())
-            else:
-                setattr(new_me, name, attr_val)
+            new_me._attributes[name] = shallowcopy(self._attributes[name])
 
         new_me._loader = self._loader
         new_me._variable_manager = self._variable_manager

lib/ansible/playbook/become.py

@@ -102,29 +102,3 @@ class Become:
             if become_user is None:
                 become_user = C.DEFAULT_BECOME_USER
 
-    def _get_attr_become(self):
-        '''
-        Override for the 'become' getattr fetcher, used from Base.
-        '''
-        if hasattr(self, '_get_parent_attribute'):
-            return self._get_parent_attribute('become')
-        else:
-            return self._attributes['become']
-
-    def _get_attr_become_method(self):
-        '''
-        Override for the 'become_method' getattr fetcher, used from Base.
-        '''
-        if hasattr(self, '_get_parent_attribute'):
-            return self._get_parent_attribute('become_method')
-        else:
-            return self._attributes['become_method']
-
-    def _get_attr_become_user(self):
-        '''
-        Override for the 'become_user' getattr fetcher, used from Base.
-        '''
-        if hasattr(self, '_get_parent_attribute'):
-            return self._get_parent_attribute('become_user')
-        else:
-            return self._attributes['become_user']

lib/ansible/playbook/block.py

@@ -278,6 +278,9 @@ class Block(Base, Become, Conditional, Taggable):
             for dep in dep_chain:
                 dep.set_loader(loader)
 
+    def _get_attr_environment(self):
+        return self._get_parent_attribute('environment', extend=True)
+
     def _get_parent_attribute(self, attr, extend=False):
         '''
         Generic logic to get the attribute or parent attribute for a block value.
@@ -288,50 +291,50 @@ class Block(Base, Become, Conditional, Taggable):
             value = self._attributes[attr]
 
             if self._parent and (value is None or extend):
-                parent_value = getattr(self._parent, attr, None)
-                if extend:
-                    value = self._extend_value(value, parent_value)
-                else:
-                    value = parent_value
-            if self._role and (value is None or extend) and hasattr(self._role, attr):
-                parent_value = getattr(self._role, attr, None)
-                if extend:
-                    value = self._extend_value(value, parent_value)
-                else:
-                    value = parent_value
-
-                dep_chain = self.get_dep_chain()
-                if dep_chain and (value is None or extend):
-                    dep_chain.reverse()
-                    for dep in dep_chain:
-                        dep_value = getattr(dep, attr, None)
-                        if extend:
-                            value = self._extend_value(value, dep_value)
-                        else:
-                            value = dep_value
-
-                        if value is not None and not extend:
-                            break
-            if self._play and (value is None or extend) and hasattr(self._play, attr):
-                parent_value = getattr(self._play, attr, None)
-                if extend:
-                    value = self._extend_value(value, parent_value)
-                else:
-                    value = parent_value
+                try:
+                    parent_value = getattr(self._parent, attr, None)
+                    if extend:
+                        value = self._extend_value(value, parent_value)
+                    else:
+                        value = parent_value
+                except AttributeError:
+                    pass
+            if self._role and (value is None or extend):
+                try:
+                    parent_value = getattr(self._role, attr, None)
+                    if extend:
+                        value = self._extend_value(value, parent_value)
+                    else:
+                        value = parent_value
+
+                    dep_chain = self.get_dep_chain()
+                    if dep_chain and (value is None or extend):
+                        dep_chain.reverse()
+                        for dep in dep_chain:
+                            dep_value = getattr(dep, attr, None)
+                            if extend:
+                                value = self._extend_value(value, dep_value)
+                            else:
+                                value = dep_value
+
+                            if value is not None and not extend:
+                                break
+                except AttributeError:
+                    pass
+            if self._play and (value is None or extend):
+                try:
+                    parent_value = getattr(self._play, attr, None)
+                    if extend:
+                        value = self._extend_value(value, parent_value)
+                    else:
+                        value = parent_value
+                except AttributeError:
+                    pass
         except KeyError as e:
             pass
 
         return value
 
-    def _get_attr_environment(self):
-        return self._get_parent_attribute('environment')
-
-    def _get_attr_any_errors_fatal(self):
-        '''
-        Override for the 'tags' getattr fetcher, used from Base.
-        '''
-        return self._get_parent_attribute('any_errors_fatal')
-
     def filter_tagged_tasks(self, play_context, all_vars):
         '''
         Creates a new block, with task lists filtered based on the tags contained

lib/ansible/playbook/task.py

@@ -79,9 +79,9 @@ class Task(Base, Conditional, Taggable, Become):
     _delegate_facts       = FieldAttribute(isa='bool', default=False)
     _failed_when          = FieldAttribute(isa='list', default=[])
     _first_available_file = FieldAttribute(isa='list')
-    _loop                 = FieldAttribute(isa='string', private=True)
-    _loop_args            = FieldAttribute(isa='list', private=True)
-    _loop_control         = FieldAttribute(isa='class', class_type=LoopControl)
+    _loop                 = FieldAttribute(isa='string', private=True, inherit=False)
+    _loop_args            = FieldAttribute(isa='list', private=True, inherit=False)
+    _loop_control         = FieldAttribute(isa='class', class_type=LoopControl, inherit=False)
     _name                 = FieldAttribute(isa='string', default='')
     _notify               = FieldAttribute(isa='list')
     _poll                 = FieldAttribute(isa='int')
@@ -401,10 +401,10 @@ class Task(Base, Conditional, Taggable, Become):
         '''
         Generic logic to get the attribute or parent attribute for a task value.
         '''
+
         value = None
         try:
             value = self._attributes[attr]
-
             if self._parent and (value is None or extend):
                 parent_value = getattr(self._parent, attr, None)
                 if extend:
@@ -420,23 +420,7 @@ class Task(Base, Conditional, Taggable, Become):
         '''
         Override for the 'tags' getattr fetcher, used from Base.
         '''
-        environment = self._attributes['environment']
-        parent_environment = self._get_parent_attribute('environment', extend=True)
-        if parent_environment is not None:
-            environment = self._extend_value(environment, parent_environment)
-        return environment
-
-    def _get_attr_any_errors_fatal(self):
-        '''
-        Override for the 'tags' getattr fetcher, used from Base.
-        '''
-        return self._get_parent_attribute('any_errors_fatal')
-
-    def _get_attr_loop(self):
-        return self._attributes['loop']
-
-    def _get_attr_loop_control(self):
-        return self._attributes['loop_control']
+        return self._get_parent_attribute('environment', extend=True)
 
     def get_dep_chain(self):
         if self._parent: