Always eager load the raw_template for a stack

The vast majority of stack fetches are immediately followed by a
raw_template fetch, so this change always eagerly fetches the
raw_template for every stack fetch.

During stack versioned object creation the stack's raw_template object
is used to construct the versioned raw template object.

Change-Id: I1a6fb8fb7d069b50dd5d623c989acd5582818ae1
Related-Bug: #1479723
Related-Bug: #1523748

2 files changed, 9 insertions, 7 deletions

diff --git a/heat/objects/raw_template.py b/heat/objects/raw_template.py
index fee181378..de1fb4821 100644
--- a/heat/objects/raw_template.py
+++ b/heat/objects/raw_template.py
@@ -52,7 +52,7 @@ class RawTemplate(
     }
 
     @staticmethod
-    def _from_db_object(context, tpl, db_tpl):
+    def from_db_object(context, tpl, db_tpl):
         for field in tpl.fields:
             tpl[field] = db_tpl[field]
 
@@ -85,7 +85,7 @@ class RawTemplate(
     @classmethod
     def get_by_id(cls, context, template_id):
         raw_template_db = db_api.raw_template_get(context, template_id)
-        return cls._from_db_object(context, cls(), raw_template_db)
+        return cls.from_db_object(context, cls(), raw_template_db)
 
     @classmethod
     def encrypt_hidden_parameters(cls, tmpl):
@@ -100,8 +100,8 @@ class RawTemplate(
 
     @classmethod
     def create(cls, context, values):
-        return cls._from_db_object(context, cls(),
-                                   db_api.raw_template_create(context, values))
+        return cls.from_db_object(context, cls(),
+                                  db_api.raw_template_create(context, values))
 
     @classmethod
     def update_by_id(cls, context, template_id, values):
@@ -109,7 +109,7 @@ class RawTemplate(
         # table, not in the old location of raw_template.files
         if 'files_id' in values and values['files_id']:
             values['files'] = None
-        return cls._from_db_object(
+        return cls.from_db_object(
             context, cls(),
             db_api.raw_template_update(context, template_id, values))
 
diff --git a/heat/objects/stack.py b/heat/objects/stack.py
index 769dccdcf..1eeffd583 100644
--- a/heat/objects/stack.py
+++ b/heat/objects/stack.py
@@ -68,8 +68,10 @@ class Stack(
         for field in stack.fields:
             if field == 'raw_template':
                 stack['raw_template'] = (
-                    raw_template.RawTemplate.get_by_id(
-                        context, db_stack['raw_template_id']))
+                    raw_template.RawTemplate.from_db_object(
+                        context,
+                        raw_template.RawTemplate(),
+                        db_stack['raw_template']))
             else:
                 stack[field] = db_stack.__dict__.get(field)
         stack._context = context