[FIX] mail: remove field res_model_id for performance reasons (#19744)

addons/mail/models/ir_model.py

@@ -46,6 +46,12 @@ class IrModel(models.Model):
             model_class._inherit = parents + ['mail.thread']
         return model_class
 
+    def unlink(self):
+        # Delete followers for models that will be unlinked.
+        query = "DELETE FROM mail_followers WHERE res_model IN %s"
+        self.env.cr.execute(query, [tuple(self.mapped('model'))])
+        return super(IrModel, self).unlink()
+
 
 class IrModelField(models.Model):
     _inherit = 'ir.model.fields'

addons/mail/models/mail_followers.py

@@ -18,12 +18,11 @@ class Followers(models.Model):
     _log_access = False
     _description = 'Document Followers'
 
-    res_model_id = fields.Many2one(
-        'ir.model', 'Related Document Model',
-        index=True, required=True, ondelete='cascade',
-        help='Model of the followed resource')
+    # Note. There is no integrity check on model names for performance reasons.
+    # However, followers of unlinked models are deleted by models themselves
+    # (see 'ir.model' inheritance).
     res_model = fields.Char(
-        'Related Document Model Name', index=True, readonly=True, related='res_model_id.model', compute_sudo=True, store=True)
+        'Related Document Model Name', required=True, index=True)
     res_id = fields.Integer(
         'Related Document ID', index=True, help='Id of the followed resource')
     partner_id = fields.Many2one(
@@ -40,7 +39,6 @@ class Followers(models.Model):
         :param force: if True, delete existing followers before creating new one
                       using the subtypes given in the parameters
         """
-        res_model_id = self.env['ir.model']._get(res_model).id
         force_mode = force or (all(partner_data.values()) and all(channel_data.values()))
         generic = []
         specific = {}
@@ -50,7 +48,7 @@ class Followers(models.Model):
 
         followers = self.sudo().search([
             '&',
-            '&', ('res_model_id', '=', res_model_id), ('res_id', 'in', res_ids),
+            '&', ('res_model', '=', res_model), ('res_id', 'in', res_ids),
             '|', ('partner_id', 'in', list(partner_data)), ('channel_id', 'in', list(channel_data))])
 
         if force_mode:
@@ -82,9 +80,9 @@ class Followers(models.Model):
         gen_new_pids = [pid for pid in partner_data if pid not in p_exist]
         gen_new_cids = [cid for cid in channel_data if cid not in c_exist]
         for pid in gen_new_pids:
-            generic.append([0, 0, {'res_model_id': res_model_id, 'partner_id': pid, 'subtype_ids': [(6, 0, partner_data.get(pid) or default_subtypes.ids)]}])
+            generic.append([0, 0, {'res_model': res_model, 'partner_id': pid, 'subtype_ids': [(6, 0, partner_data.get(pid) or default_subtypes.ids)]}])
         for cid in gen_new_cids:
-            generic.append([0, 0, {'res_model_id': res_model_id, 'channel_id': cid, 'subtype_ids': [(6, 0, channel_data.get(cid) or default_subtypes.ids)]}])
+            generic.append([0, 0, {'res_model': res_model, 'channel_id': cid, 'subtype_ids': [(6, 0, channel_data.get(cid) or default_subtypes.ids)]}])
 
         # create new followers, each document at a time because of existing followers to avoid erasing
         if not force_mode:
@@ -98,13 +96,13 @@ class Followers(models.Model):
                 # subscribe new followers
                 for new_pid in new_pids:
                     command.append((0, 0, {
-                        'res_model_id': res_model_id,
+                        'res_model': res_model,
                         'partner_id': new_pid,
                         'subtype_ids': [(6, 0, partner_data.get(new_pid) or default_subtypes.ids)],
                     }))
                 for new_cid in new_cids:
                     command.append((0, 0, {
-                        'res_model_id': res_model_id,
+                        'res_model': res_model,
                         'channel_id': new_cid,
                         'subtype_ids': [(6, 0, channel_data.get(new_cid) or default_subtypes.ids)],
                     }))

addons/mail/tests/test_mail_followers.py

@@ -26,13 +26,12 @@ class TestMailFollowers(TestMail):
             'mail.test', groups.ids,
             {self.user_employee.partner_id.id: [self.mt_mg_nodef.id]},
             {test_channel.id: [self.mt_al_nodef.id]})
-        mail_channel_model_id = self.env['ir.model']._get('mail.test').id
         self.assertFalse(specific)
         self.assertEqual(len(generic), 2)
 
         items = [it[2] for it in generic]
-        self.assertEqual({item['res_model_id'] for item in items},
-                         {mail_channel_model_id})
+        self.assertEqual({item['res_model'] for item in items},
+                         {'mail.test'})
         self.assertEqual({item['channel_id'] for item in items if item.get('channel_id')},
                          {test_channel.id})
         self.assertEqual({item['partner_id'] for item in items if item.get('partner_id')},
@@ -42,9 +41,8 @@ class TestMailFollowers(TestMail):
 
     def test_m2o_command_update_selective(self):
         test_channel = self.env['mail.channel'].create({'name': 'Test'})
-        mail_channel_model_id = self.env['ir.model']._get('mail.test').id
         groups = self.test_pigs | self.test_public
-        self.env['mail.followers'].create({'partner_id': self.user_employee.partner_id.id, 'res_model_id': mail_channel_model_id, 'res_id': self.test_pigs.id})
+        self.env['mail.followers'].create({'partner_id': self.user_employee.partner_id.id, 'res_model': 'mail.test', 'res_id': self.test_pigs.id})
         generic, specific = self.env['mail.followers']._add_follower_command(
             'mail.test', groups.ids,
             {self.user_employee.partner_id.id: [self.mt_mg_nodef.id]},
@@ -53,12 +51,12 @@ class TestMailFollowers(TestMail):
         self.assertEqual(len(generic), 1)
         self.assertEqual(len(specific), 1)
 
-        self.assertEqual(generic[0][2]['res_model_id'], mail_channel_model_id)
+        self.assertEqual(generic[0][2]['res_model'], 'mail.test')
         self.assertEqual(generic[0][2]['channel_id'], test_channel.id)
         self.assertEqual(set(generic[0][2]['subtype_ids'][0][2]), set(self.default_group_subtypes.ids))
 
         self.assertEqual(list(specific), [self.test_public.id])
-        self.assertEqual(specific[self.test_public.id][0][2]['res_model_id'], mail_channel_model_id)
+        self.assertEqual(specific[self.test_public.id][0][2]['res_model'], 'mail.test')
         self.assertEqual(specific[self.test_public.id][0][2]['partner_id'], self.user_employee.partner_id.id)
         self.assertEqual(set(specific[self.test_public.id][0][2]['subtype_ids'][0][2]), set([self.mt_mg_nodef.id]))
 
@@ -139,7 +137,7 @@ class TestMailFollowers(TestMail):
         test_channel = self.env['mail.channel'].create({'name': 'Follower Channel'})
         with self.assertRaises(IntegrityError), mute_logger('odoo.sql_db'):
             self.env['mail.followers'].create({
-                'res_model_id': self.env['ir.model']._get('mail.test').id,
+                'res_model': test_record._name,
                 'res_id': test_record.id,
                 'partner_id': self.user_employee.partner_id.id,
                 'channel_id': test_channel.id,

addons/mail/views/mail_followers_views.xml

@@ -9,7 +9,7 @@
             <field name="priority">10</field>
             <field name="arch" type="xml">
                 <tree string="Followers">
-                    <field name="res_model_id"/>
+                    <field name="res_model"/>
                     <field name="res_id"/>
                     <field name="partner_id"/>
                 </tree>
@@ -24,7 +24,7 @@
                     <sheet>
                         <group>
                             <group>
-                                <field name="res_model_id"/>
+                                <field name="res_model"/>
                                 <field name="partner_id"/>
                             </group>
                             <group>

odoo/addons/test_performance/tests/test_performance.py

@@ -180,7 +180,7 @@ class TestPerformance(TransactionCase):
         model = self.env['test_performance.mail']
         model.with_context(tracking_disable=True).create({'name': self.str('X')})
 
-    @queryCount(admin=39, demo=55)
+    @queryCount(admin=38, demo=54)
     def test_create_mail_with_tracking(self):
         """ Create records inheriting from 'mail.thread' (with field tracking). """
         model = self.env['test_performance.mail']