Added create and update hooks to version mixin

Objects using the version mixin will now have the version automatically
added or updated in the create and update hooks respectively.

Change-Id: I198eb89b45f0f16abb97611b8e43c106e24b9b49
Closes-Bug: #1808331
Co-Authored-By: Omer Anson <omer.anson@toganetworks.com>

doc/source/devrefs/models.rst

@@ -233,8 +233,8 @@ director objects better we could define a common class:
            super(AccessMixin, self).on_create_pre()
            self.created_at = datetime.datetime.now()
 
-       def on_update_pre(self):
+       def on_update_pre(self, orig):
-           super(AccessMixin, self).on_update_pre()
+           super(AccessMixin, self).on_update_pre(orig)
            self.updated_at = datetime.datetime.now()
 
 The above code updates the relevant fields on create/update operations, so if

doc/source/specs/nb_api_refactor.rst

@@ -189,6 +189,7 @@ operations performed in NbApi, e.g.
 
  * `on_update_pre` - Called on the object each time it is updated, can be used
    for example to generate a new version or trigger updates on other objects.
+   Gets the original object that exists in the database as a parameter.
 
 Since those hooks are methods on objects themselves, we can use super() to
 chain all needed hooks in parents and mixins, according to Python's native MRO.

dragonflow/db/api_nb.py

@@ -14,6 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import copy
 import time
 import traceback
 
@@ -201,6 +202,7 @@ class NbApi(object):
         """
         model = type(obj)
         full_obj = self.get(obj)
+        db_obj = copy.copy(full_obj)
 
         if full_obj is None:
             raise df_exceptions.DBKeyNotFound(key=obj.id)
@@ -210,7 +212,7 @@ class NbApi(object):
         if not changed_fields:
             return
 
-        full_obj.on_update_pre()
+        full_obj.on_update_pre(db_obj)
         serialized_obj = full_obj.to_json()
         topic = _get_topic(full_obj)
 

dragonflow/db/model_framework.py

@@ -156,7 +156,7 @@ class _CommonBase(models.Base):
         '''
         pass
 
-    def on_update_pre(self):
+    def on_update_pre(self, orig):
         '''Hook function called before object is updated in the NB database.
         '''
         pass

dragonflow/db/models/core.py

@@ -65,6 +65,6 @@ class Listener(mf.ModelBase):
         super(Listener, self).on_create_pre()
         self.update_timestamp()
 
-    def on_update_pre(self):
+    def on_update_pre(self, orig):
-        super(Listener, self).on_update_pre()
+        super(Listener, self).on_update_pre(orig)
         self.update_timestamp()

dragonflow/db/models/mixins.py

@@ -36,6 +36,16 @@ class BasicEvents(mf.MixinBase):
 class Version(mf.MixinBase):
     version = fields.IntField()
 
+    def on_create_pre(self):
+        super(Version, self).on_create_pre()
+        if self.version is None:
+            self.version = 1
+
+    def on_update_pre(self, orig):
+        super(Version, self).on_update_pre(orig)
+        if self.version == orig.version:
+            self.version += 1
+
     def is_newer_than(self, other):
         return other is None or self.version > other.version
 

dragonflow/tests/unit/test_mixins.py

@@ -0,0 +1,48 @@
+#    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.
+from jsonmodels import fields
+import mock
+import testtools
+
+from dragonflow.db import api_nb
+import dragonflow.db.model_framework as mf
+from dragonflow.db.models import mixins
+from dragonflow.tests import base as tests_base
+from dragonflow.tests.common import utils
+
+
+@mf.register_model
+@mf.construct_nb_db_model
+class FieldTestModel(mf.ModelBase, mixins.Version):
+    table_name = 'test_mixins'
+    field = fields.IntField()
+
+
+class TestMixinVersions(tests_base.BaseTestCase):
+    def setUp(self):
+        super(TestMixinVersions, self).setUp()
+        self.api_nb = api_nb.NbApi(db_driver=mock.Mock())
+
+    def test_on_create(self):
+        instance = FieldTestModel(id='11111111')
+        self.api_nb.create(instance, True)
+        self.assertEqual(1, instance.version)
+
+    @testtools.skip('review/480194')
+    @utils.with_nb_objects(
+        FieldTestModel(id='11111111', version=1, field=1)
+    )
+    def test_on_update(self):
+        instance = FieldTestModel(id='11111111', field=2)
+        self.api_nb.update(instance, True)
+        db_inst = self.api_nb.get(FieldTestModel(id='11111111'))
+        self.assertEqual(2, db_inst.version)