Handle heat with SQLAlchemy >= 0.8

Lots of unit tests failed with the new SQLAlchemy(0.8.2)
which makes build failed, this patch will fix all the related
bug like no MutableType and changed module name in SQLAlchemy(0.8.2)

Fixes bug #1199435

Change-Id: I67d7588db088dd3dd88d44c32e78c6b8a4708bff

heat/db/sqlalchemy/models.py

@@ -32,7 +32,7 @@ from sqlalchemy.orm.session import Session
 BASE = declarative_base()
 
 
-class Json(types.TypeDecorator, types.MutableType):
+class Json(types.TypeDecorator):
     impl = types.Text
 
     def process_bind_param(self, value, dialect):
@@ -41,6 +41,15 @@ class Json(types.TypeDecorator, types.MutableType):
     def process_result_value(self, value, dialect):
         return loads(value)
 
+# TODO(leizhang) When we removed sqlalchemy 0.7 dependence
+# we can import MutableDict directly and remove ./mutable.py
+try:
+    from sqlalchemy.ext.mutable import MutableDict as sa_MutableDict
+    sa_MutableDict.associate_with(Json)
+except ImportError:
+    from heat.db.sqlalchemy.mutable import MutableDict
+    MutableDict.associate_with(Json)
+
 
 class HeatBase(object):
     """Base class for Heat Models."""

heat/db/sqlalchemy/mutable.py

@@ -0,0 +1,64 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+#
+#    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.
+#
+# The MIT License
+#
+# ext/mutable.py
+# Copyright (C) 2005-2013 the SQLAlchemy authors
+# and contributors <see AUTHORS file>
+#
+# This module is part of SQLAlchemy and is released under
+# the MIT License: http://www.opensource.org/lic enses/mit-license.php
+"""
+Submitted on behalf of a third-party: sqlalchemy
+"""
+from sqlalchemy.ext.mutable import Mutable
+
+
+class MutableDict(Mutable, dict):
+    """A dictionary type that implements :class:`.Mutable`.
+
+    .. versionadded:: 0.8
+
+    """
+
+    def __setitem__(self, key, value):
+        """Detect dictionary set events and emit change events."""
+        dict.__setitem__(self, key, value)
+        self.changed()
+
+    def __delitem__(self, key):
+        """Detect dictionary del events and emit change events."""
+        dict.__delitem__(self, key)
+        self.changed()
+
+    def clear(self):
+        dict.clear(self)
+        self.changed()
+
+    @classmethod
+    def coerce(cls, key, value):
+        """Convert plain dictionary to MutableDict."""
+        if not isinstance(value, MutableDict):
+            if isinstance(value, dict):
+                return MutableDict(value)
+            return Mutable.coerce(key, value)
+        else:
+            return value
+
+    def __getstate__(self):
+        return dict(self)
+
+    def __setstate__(self, state):
+        self.update(state)