Add denormalized relations

netbox/ipam/apps.py

@@ -1,5 +1,7 @@
 from django.apps import AppConfig
 
+from netbox import denormalized
+
 
 class IPAMConfig(AppConfig):
     name = "ipam"
@@ -8,6 +10,16 @@ class IPAMConfig(AppConfig):
     def ready(self):
         from netbox.models.features import register_models
         from . import signals, search  # noqa: F401
+        from .models import Prefix
 
         # Register models
         register_models(*self.get_models())
+
+        # Register denormalized fields
+        denormalized.register(Prefix, '_site', {
+            '_region': 'region',
+            '_sitegroup': 'group',
+        })
+        denormalized.register(Prefix, '_location', {
+            '_site': 'site',
+        })

netbox/ipam/migrations/0071_prefix_scope.py

@@ -23,7 +23,7 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        # Add the scope GenericForeignKey
+        # Add the `scope` GenericForeignKey
         migrations.AddField(
             model_name='prefix',
             name='scope_id',
@@ -46,10 +46,4 @@ class Migration(migrations.Migration):
             code=copy_site_assignments,
             reverse_code=migrations.RunPython.noop
         ),
-
-        # Delete the site ForeignKey
-        migrations.RemoveField(
-            model_name='prefix',
-            name='site',
-        ),
     ]

netbox/ipam/migrations/0072_prefix_cached_relations.py

@@ -0,0 +1,61 @@
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+def populate_denormalized_fields(apps, schema_editor):
+    """
+    Copy site ForeignKey values to the scope GFK.
+    """
+    Prefix = apps.get_model('ipam', 'Prefix')
+
+    prefixes = Prefix.objects.filter(site__isnull=False).prefetch_related('site')
+    for prefix in prefixes:
+        prefix._region_id = prefix.site.region_id
+        prefix._sitegroup_id = prefix.site.group_id
+        prefix._site_id = prefix.site_id
+        # Note: Location cannot be set prior to migration
+
+    Prefix.objects.bulk_update(prefixes, ['_region', '_sitegroup', '_site'])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('dcim', '0192_poweroutlet_color'),
+        ('ipam', '0071_prefix_scope'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='prefix',
+            name='_location',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='dcim.location'),
+        ),
+        migrations.AddField(
+            model_name='prefix',
+            name='_region',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='dcim.region'),
+        ),
+        migrations.AddField(
+            model_name='prefix',
+            name='_site',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='dcim.site'),
+        ),
+        migrations.AddField(
+            model_name='prefix',
+            name='_sitegroup',
+            field=models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to='dcim.sitegroup'),
+        ),
+
+        # Populate denormalized FK values
+        migrations.RunPython(
+            code=populate_denormalized_fields,
+            reverse_code=migrations.RunPython.noop
+        ),
+
+        # Delete the site ForeignKey
+        migrations.RemoveField(
+            model_name='prefix',
+            name='site',
+        ),
+    ]

netbox/ipam/models/ip.py

@@ -1,4 +1,5 @@
 import netaddr
+from django.apps import apps
 from django.contrib.contenttypes.fields import GenericForeignKey
 from django.core.exceptions import ValidationError
 from django.db import models
@@ -270,6 +271,32 @@ class Prefix(ContactsMixin, GetAvailablePrefixesMixin, PrimaryModel):
         help_text=_("Treat as fully utilized")
     )
 
+    # Cached associations to enable efficient filtering
+    _location = models.ForeignKey(
+        to='dcim.Location',
+        on_delete=models.CASCADE,
+        blank=True,
+        null=True
+    )
+    _site = models.ForeignKey(
+        to='dcim.Site',
+        on_delete=models.CASCADE,
+        blank=True,
+        null=True
+    )
+    _region = models.ForeignKey(
+        to='dcim.Region',
+        on_delete=models.CASCADE,
+        blank=True,
+        null=True
+    )
+    _sitegroup = models.ForeignKey(
+        to='dcim.SiteGroup',
+        on_delete=models.CASCADE,
+        blank=True,
+        null=True
+    )
+
     # Cached depth & child counts
     _depth = models.PositiveSmallIntegerField(
         default=0,
@@ -331,8 +358,37 @@ class Prefix(ContactsMixin, GetAvailablePrefixesMixin, PrimaryModel):
             # Clear host bits from prefix
             self.prefix = self.prefix.cidr
 
+        # Cache objects associated with the terminating object (for filtering)
+        self.cache_related_objects()
+
         super().save(*args, **kwargs)
 
+    def cache_related_objects(self):
+        if self.scope is None:
+            return
+        scope_type = self.scope_type.model_class()
+        if scope_type == apps.get_model('dcim', 'region'):
+            self._region = self.scope
+            self._sitegroup = None
+            self._site = None
+            self._location = None
+        elif scope_type == apps.get_model('dcim', 'sitegroup'):
+            self._region = None
+            self._sitegroup = self.scope
+            self._site = None
+            self._location = None
+        elif scope_type == apps.get_model('dcim', 'site'):
+            self._region = self.scope.region
+            self._sitegroup = self.scope.group
+            self._site = self.scope
+            self._location = None
+        elif scope_type == apps.get_model('dcim', 'location'):
+            self._region = self.scope.site.region
+            self._sitegroup = self.scope.site.group
+            self._site = self.scope.site
+            self._location = self.scope
+    cache_related_objects.alters_data = True
+
     @property
     def family(self):
         return self.prefix.version if self.prefix else None