[IMP] models: use slots for BaseModel

This restricts the attributes of a BaseModel instance to `env`, `_ids`
and `_prefetch_ids`.  This way, one can only assign fields on a record;
other assignments are programming errors.

This also reduces the memory footprint of records from 168 to 64 bytes
(-62%), and makes their instanciation faster.

closes odoo/odoo#51075

Related: odoo/enterprise#10529
Signed-off-by: Raphael Collet (rco) <rco@openerp.com>

1 files changed, 3 insertions, 16 deletions

diff --git a/odoo/addons/test_new_api/tests/test_attributes.py b/odoo/addons/test_new_api/tests/test_attributes.py
index 94a048f2554..27853d9a16e 100644
--- a/odoo/addons/test_new_api/tests/test_attributes.py
+++ b/odoo/addons/test_new_api/tests/test_attributes.py
@@ -1,25 +1,12 @@
 # -*- coding: utf-8 -*-
 from odoo.tests import common
 
-ANSWER_TO_ULTIMATE_QUESTION = 42
 
 class TestAttributes(common.TransactionCase):
 
-    def test_we_can_add_attributes(self):
+    def test_we_cannot_add_attributes(self):
         Model = self.env['test_new_api.category']
         instance = Model.create({'name': 'Foo'})
 
-        # assign an unknown attribute
-        instance.unknown = ANSWER_TO_ULTIMATE_QUESTION
-
-        # Does the attribute exist in the instance of the model ?
-        self.assertTrue(hasattr(instance, 'unknown'))
-
-        # Is it the right type ?
-        self.assertIsInstance(instance.unknown, int)
-
-        # Is it the right value, in case of, we don't know ;-)
-        self.assertEqual(instance.unknown, ANSWER_TO_ULTIMATE_QUESTION)
-
-        # We are paranoiac !
-        self.assertEqual(getattr(instance, 'unknown'), ANSWER_TO_ULTIMATE_QUESTION)
+        with self.assertRaises(AttributeError):
+            instance.unknown = 42