Cache each CablePath on its originating endpoint

netbox/circuits/migrations/0021_cablepath.py

@@ -0,0 +1,20 @@
+# Generated by Django 3.1 on 2020-10-02 19:43
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0120_cablepath'),
+        ('circuits', '0020_custom_field_data'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='circuittermination',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+    ]

netbox/dcim/migrations/0120_cablepath.py

@@ -1,4 +1,4 @@
-# Generated by Django 3.1 on 2020-10-02 15:49
+# Generated by Django 3.1 on 2020-10-02 19:43
 
 import dcim.fields
 from django.db import migrations, models
@@ -28,4 +28,34 @@ class Migration(migrations.Migration):
                 'unique_together': {('origin_type', 'origin_id')},
             },
         ),
+        migrations.AddField(
+            model_name='consoleport',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+        migrations.AddField(
+            model_name='consoleserverport',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+        migrations.AddField(
+            model_name='interface',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+        migrations.AddField(
+            model_name='powerfeed',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+        migrations.AddField(
+            model_name='poweroutlet',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
+        migrations.AddField(
+            model_name='powerport',
+            name='_path',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, to='dcim.cablepath'),
+        ),
     ]

netbox/dcim/models/device_components.py

@@ -126,38 +126,30 @@ class CableTermination(models.Model):
 
 class PathEndpoint(models.Model):
     """
-    Any object which may serve as either endpoint of a CablePath.
+    Any object which may serve as the originating endpoint of a CablePath.
     """
-    _paths = GenericRelation(
+    _path = models.ForeignKey(
         to='dcim.CablePath',
-        content_type_field='origin_type',
-        object_id_field='origin_id',
-        related_query_name='%(class)s'
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True
     )
 
     class Meta:
         abstract = True
 
     def trace(self):
-        if self.path is None:
+        if self._path is None:
             return []
 
         # Construct the complete path
-        path = [self, *[path_node_to_object(obj) for obj in self.path.path], self.path.destination]
-        assert not len(path) % 3, f"Invalid path length for CablePath #{self.pk}: {len(self.path)} elements in path"
+        path = [self, *[path_node_to_object(obj) for obj in self._path.path], self._path.destination]
+        assert not len(path) % 3,\
+            f"Invalid path length for CablePath #{self.pk}: {len(self._path.path)} elements in path"
 
         # Return the path as a list of three-tuples (A termination, cable, B termination)
         return list(zip(*[iter(path)] * 3))
 
-    @property
-    def path(self):
-        """
-        Return the _complete_ CablePath associated with this origin point, if any.
-        """
-        if not hasattr(self, '_path'):
-            self._path = self._paths.filter(destination_id__isnull=False).first()
-        return self._path
-
 
 #
 # Console ports

netbox/dcim/models/devices.py

@@ -1204,6 +1204,13 @@ class CablePath(models.Model):
         path = ', '.join([str(path_node_to_object(node)) for node in self.path])
         return f"Path #{self.pk}: {self.origin} to {self.destination} via ({path})"
 
+    def save(self, *args, **kwargs):
+        super().save(*args, **kwargs)
+
+        # Record a direct reference to this CablePath on its originating object
+        model = self.origin._meta.model
+        model.objects.filter(pk=self.origin.pk).update(_path=self.pk)
+
 
 #
 # Virtual chassis

netbox/dcim/signals.py

@@ -1,7 +1,7 @@
 import logging
 
 from django.contrib.contenttypes.models import ContentType
-from django.db.models.signals import post_save, pre_delete
+from django.db.models.signals import post_save, post_delete, pre_delete
 from django.db import transaction
 from django.dispatch import receiver
 
@@ -91,7 +91,7 @@ def update_connected_endpoints(instance, created, **kwargs):
             rebuild_paths(instance)
 
 
-@receiver(pre_delete, sender=Cable)
+@receiver(post_delete, sender=Cable)
 def nullify_connected_endpoints(instance, **kwargs):
     """
     When a Cable is deleted, check for and update its two connected endpoints
@@ -108,18 +108,15 @@ def nullify_connected_endpoints(instance, **kwargs):
         instance.termination_b.cable = None
         instance.termination_b.save()
 
-    # Delete any dependent cable paths
-    cable_paths = CablePath.objects.filter(path__contains=[object_to_path_node(instance)])
-    retrace_queue = [cp.origin for cp in cable_paths]
-    deleted, _ = cable_paths.delete()
-    logger.info(f'Deleted {deleted} cable paths')
-
-    # Retrace cable paths from the origins of deleted paths
-    for origin in retrace_queue:
-        # Delete and recreate all CablePaths for this origin point
-        # TODO: We can probably be smarter about skipping unchanged paths
-        CablePath.objects.filter(
-            origin_type=ContentType.objects.get_for_model(origin),
-            origin_id=origin.pk
-        ).delete()
-        create_cablepath(origin)
+    # Delete and retrace any dependent cable paths
+    for cablepath in CablePath.objects.filter(path__contains=[object_to_path_node(instance)]):
+        path, destination, is_connected = trace_path(cablepath.origin)
+        if path:
+            CablePath.objects.filter(pk=cablepath.pk).update(
+                path=path,
+                destination_type=ContentType.objects.get_for_model(destination) if destination else None,
+                destination_id=destination.pk if destination else None,
+                is_connected=is_connected
+            )
+        else:
+            cablepath.delete()

netbox/dcim/tests/test_cablepaths.py

@@ -132,6 +132,8 @@ class CablePathTestCase(TestCase):
         :param path: Sequence of objects comprising the intermediate path (optional)
         :param is_connected: Boolean indicating whether the end-to-end path is complete and active (optional)
         :param msg: Custom failure message (optional)
+
+        :return: The matching CablePath (if any)
         """
         kwargs = {
             'origin_type': ContentType.objects.get_for_model(origin),
@@ -152,7 +154,34 @@ class CablePathTestCase(TestCase):
                 msg = f"Missing path from {origin} to {destination}"
             else:
                 msg = f"Missing partial path originating from {origin}"
-        self.assertEqual(CablePath.objects.filter(**kwargs).count(), 1, msg=msg)
+
+        cablepath = CablePath.objects.filter(**kwargs).first()
+        self.assertIsNotNone(cablepath, msg=msg)
+
+        return cablepath
+
+    def assertPathIsSet(self, origin, cablepath, msg=None):
+        """
+        Assert that a specific CablePath instance is set as the path on the origin.
+
+        :param origin: The originating path endpoint
+        :param cablepath: The CablePath instance originating from this endpoint
+        :param msg: Custom failure message (optional)
+        """
+        if msg is None:
+            msg = f"Path #{cablepath.pk} not set on originating endpoint {origin}"
+        self.assertEqual(origin._path_id, cablepath.pk, msg=msg)
+
+    def assertPathIsNotSet(self, origin, msg=None):
+        """
+        Assert that a specific CablePath instance is set as the path on the origin.
+
+        :param origin: The originating path endpoint
+        :param msg: Custom failure message (optional)
+        """
+        if msg is None:
+            msg = f"Path #{origin._path_id} set as origin on {origin}; should be None!"
+        self.assertIsNone(origin._path_id, msg=msg)
 
     def test_101_interface_to_interface(self):
         """
@@ -161,19 +190,23 @@ class CablePathTestCase(TestCase):
         # Create cable 1
         cable1 = Cable(termination_a=self.interface1, termination_b=self.interface2)
         cable1.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.interface1,
             destination=self.interface2,
             path=(cable1,),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.interface2,
             destination=self.interface1,
             path=(cable1,),
             is_connected=True
         )
         self.assertEqual(CablePath.objects.count(), 2)
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.assertPathIsSet(self.interface1, path1)
+        self.assertPathIsSet(self.interface2, path2)
 
         # Delete cable 1
         cable1.delete()
@@ -181,26 +214,30 @@ class CablePathTestCase(TestCase):
         # Check that all CablePaths have been deleted
         self.assertEqual(CablePath.objects.count(), 0)
 
-    def test_103_consoleport_to_consoleserverport(self):
+    def test_102_consoleport_to_consoleserverport(self):
         """
         [CP1] --C1-- [CSP1]
         """
         # Create cable 1
         cable1 = Cable(termination_a=self.consoleport1, termination_b=self.consoleserverport1)
         cable1.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.consoleport1,
             destination=self.consoleserverport1,
             path=(cable1,),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.consoleserverport1,
             destination=self.consoleport1,
             path=(cable1,),
             is_connected=True
         )
         self.assertEqual(CablePath.objects.count(), 2)
+        self.consoleport1.refresh_from_db()
+        self.consoleserverport1.refresh_from_db()
+        self.assertPathIsSet(self.consoleport1, path1)
+        self.assertPathIsSet(self.consoleserverport1, path2)
 
         # Delete cable 1
         cable1.delete()
@@ -208,26 +245,30 @@ class CablePathTestCase(TestCase):
         # Check that all CablePaths have been deleted
         self.assertEqual(CablePath.objects.count(), 0)
 
-    def test_104_powerport_to_poweroutlet(self):
+    def test_103_powerport_to_poweroutlet(self):
         """
         [PP1] --C1-- [PO1]
         """
         # Create cable 1
         cable1 = Cable(termination_a=self.powerport1, termination_b=self.poweroutlet1)
         cable1.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.powerport1,
             destination=self.poweroutlet1,
             path=(cable1,),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.poweroutlet1,
             destination=self.powerport1,
             path=(cable1,),
             is_connected=True
         )
         self.assertEqual(CablePath.objects.count(), 2)
+        self.powerport1.refresh_from_db()
+        self.poweroutlet1.refresh_from_db()
+        self.assertPathIsSet(self.powerport1, path1)
+        self.assertPathIsSet(self.poweroutlet1, path2)
 
         # Delete cable 1
         cable1.delete()
@@ -235,26 +276,30 @@ class CablePathTestCase(TestCase):
         # Check that all CablePaths have been deleted
         self.assertEqual(CablePath.objects.count(), 0)
 
-    def test_105_powerport_to_powerfeed(self):
+    def test_104_powerport_to_powerfeed(self):
         """
         [PP1] --C1-- [PF1]
         """
         # Create cable 1
         cable1 = Cable(termination_a=self.powerport1, termination_b=self.powerfeed1)
         cable1.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.powerport1,
             destination=self.powerfeed1,
             path=(cable1,),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.powerfeed1,
             destination=self.powerport1,
             path=(cable1,),
             is_connected=True
         )
         self.assertEqual(CablePath.objects.count(), 2)
+        self.powerport1.refresh_from_db()
+        self.powerfeed1.refresh_from_db()
+        self.assertPathIsSet(self.powerport1, path1)
+        self.assertPathIsSet(self.powerfeed1, path2)
 
         # Delete cable 1
         cable1.delete()
@@ -262,26 +307,30 @@ class CablePathTestCase(TestCase):
         # Check that all CablePaths have been deleted
         self.assertEqual(CablePath.objects.count(), 0)
 
-    def test_106_interface_to_circuittermination(self):
+    def test_105_interface_to_circuittermination(self):
         """
         [PP1] --C1-- [CT1A]
         """
         # Create cable 1
         cable1 = Cable(termination_a=self.interface1, termination_b=self.circuittermination1_A)
         cable1.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.interface1,
             destination=self.circuittermination1_A,
             path=(cable1,),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.circuittermination1_A,
             destination=self.interface1,
             path=(cable1,),
             is_connected=True
         )
         self.assertEqual(CablePath.objects.count(), 2)
+        self.interface1.refresh_from_db()
+        self.circuittermination1_A.refresh_from_db()
+        self.assertPathIsSet(self.interface1, path1)
+        self.assertPathIsSet(self.circuittermination1_A, path2)
 
         # Delete cable 1
         cable1.delete()
@@ -293,6 +342,9 @@ class CablePathTestCase(TestCase):
         """
         [IF1] --C1-- [FP5] [RP5] --C2-- [IF2]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+
         # Create cable 1
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port5_1)
         cable1.save()
@@ -323,19 +375,28 @@ class CablePathTestCase(TestCase):
 
         # Delete cable 2
         cable2.delete()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.interface1,
             destination=None,
             path=(cable1, self.front_port5_1, self.rear_port5),
             is_connected=False
         )
         self.assertEqual(CablePath.objects.count(), 1)
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.assertPathIsSet(self.interface1, path1)
+        self.assertPathIsNotSet(self.interface2)
 
     def test_202_multiple_paths_via_pass_through(self):
         """
         [IF1] --C1-- [FP1:1] [RP1] --C3-- [RP2] [FP2:1] --C4-- [IF3]
         [IF2] --C2-- [FP1:2]                    [FP2:2] --C5-- [IF4]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.interface3.refresh_from_db()
+        self.interface4.refresh_from_db()
+
         # Create cables 1-2
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port1_1)
         cable1.save()
@@ -377,7 +438,7 @@ class CablePathTestCase(TestCase):
         cable4.save()
         cable5 = Cable(termination_a=self.front_port2_2, termination_b=self.interface4)
         cable5.save()
-        self.assertPathExists(
+        path1 = self.assertPathExists(
             origin=self.interface1,
             destination=self.interface3,
             path=(
@@ -386,7 +447,7 @@ class CablePathTestCase(TestCase):
             ),
             is_connected=True
         )
-        self.assertPathExists(
+        path2 = self.assertPathExists(
             origin=self.interface2,
             destination=self.interface4,
             path=(
@@ -395,7 +456,7 @@ class CablePathTestCase(TestCase):
             ),
             is_connected=True
         )
-        self.assertPathExists(
+        path3 = self.assertPathExists(
             origin=self.interface3,
             destination=self.interface1,
             path=(
@@ -404,7 +465,7 @@ class CablePathTestCase(TestCase):
             ),
             is_connected=True
         )
-        self.assertPathExists(
+        path4 = self.assertPathExists(
             origin=self.interface4,
             destination=self.interface2,
             path=(
@@ -421,12 +482,25 @@ class CablePathTestCase(TestCase):
         # Check for four partial paths; one from each interface
         self.assertEqual(CablePath.objects.filter(destination_id__isnull=True).count(), 4)
         self.assertEqual(CablePath.objects.filter(destination_id__isnull=False).count(), 0)
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.interface3.refresh_from_db()
+        self.interface4.refresh_from_db()
+        self.assertPathIsSet(self.interface1, path1)
+        self.assertPathIsSet(self.interface2, path2)
+        self.assertPathIsSet(self.interface3, path3)
+        self.assertPathIsSet(self.interface4, path4)
 
     def test_203_multiple_paths_via_nested_pass_throughs(self):
         """
         [IF1] --C1-- [FP1:1] [RP1] --C3-- [FP2:1] [RP2] --C4-- [RP3] [FP3:1] --C5-- [RP4] [FP4:1] --C6-- [IF3]
         [IF2] --C2-- [FP1:2]                                                              [FP4:2] --C7-- [IF4]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.interface3.refresh_from_db()
+        self.interface4.refresh_from_db()
+
         # Create cables 1-2, 6-7
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port1_1)
         cable1.save()
@@ -502,6 +576,11 @@ class CablePathTestCase(TestCase):
         [IF1] --C1-- [FP1:1] [RP1] --C3-- [RP2] [FP2:1] --C4-- [FP3:1] [RP3] --C6-- [RP4] [FP4:1] --C7-- [IF3]
         [IF2] --C2-- [FP1:2]                    [FP2:1] --C5-- [FP3:1]                    [FP4:2] --C8-- [IF4]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.interface3.refresh_from_db()
+        self.interface4.refresh_from_db()
+
         # Create cables 1-3, 6-8
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port1_1)
         cable1.save()
@@ -576,6 +655,11 @@ class CablePathTestCase(TestCase):
         [IF1] --C1-- [FP1:1] [RP1] --C3-- [FP5] [RP5] --C4-- [RP2] [FP2:1] --C5-- [IF3]
         [IF2] --C2-- [FP1:2]                                       [FP2:2] --C6-- [IF4]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+        self.interface3.refresh_from_db()
+        self.interface4.refresh_from_db()
+
         # Create cables 1-2, 5-6
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port1_1)  # IF1 -> FP1:1
         cable1.save()
@@ -641,6 +725,9 @@ class CablePathTestCase(TestCase):
         """
         [IF1] --C1-- [FP5] [RP5] --C2-- [RP6] [FP6] --C3-- [IF2]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+
         # Create cable 2
         cable2 = Cable(termination_a=self.rear_port5, termination_b=self.rear_port6)
         cable2.save()
@@ -684,6 +771,9 @@ class CablePathTestCase(TestCase):
         """
         [IF1] --C1-- [FP5] [RP5] --C2-- [IF2]
         """
+        self.interface1.refresh_from_db()
+        self.interface2.refresh_from_db()
+
         # Create cables 1 and 2
         cable1 = Cable(termination_a=self.interface1, termination_b=self.front_port5_1)
         cable1.save()