add cached count fields to erratum model with m2m signals

Author: furlongm

errata/apps.py

@@ -26,6 +26,8 @@ def ready(self):
         from django.db.models.signals import post_save
         from django.utils import timezone
 
+        import errata.signals  # noqa: F401
+
         def set_initial_last_run(sender, instance, created, **kwargs):
             if created and instance.name == 'update_errata_cves_cwes_every_12_hours':
                 instance.last_run_at = timezone.now() - timedelta(days=1)

errata/migrations/0008_add_cached_count_fields.py

@@ -0,0 +1,38 @@
+# Generated by Django 4.2.28 on 2026-02-13 06:44
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('errata', '0007_alter_erratum_fixed_packages'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='erratum',
+            name='affected_packages_count',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='erratum',
+            name='cves_count',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='erratum',
+            name='fixed_packages_count',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='erratum',
+            name='osreleases_count',
+            field=models.PositiveIntegerField(default=0),
+        ),
+        migrations.AddField(
+            model_name='erratum',
+            name='references_count',
+            field=models.PositiveIntegerField(default=0),
+        ),
+    ]

errata/migrations/0009_backfill_cached_counts.py

@@ -0,0 +1,45 @@
+# Copyright 2026 Marcus Furlong <furlongm@gmail.com>
+#
+# This file is part of Patchman.
+#
+# Patchman is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3 only.
+#
+# Patchman is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Patchman. If not, see <http://www.gnu.org/licenses/>
+
+from django.db import migrations
+
+
+def backfill_counts(apps, schema_editor):
+    Erratum = apps.get_model('errata', 'Erratum')
+    for erratum in Erratum.objects.all().iterator():
+        erratum.affected_packages_count = erratum.affected_packages.count()
+        erratum.fixed_packages_count = erratum.fixed_packages.count()
+        erratum.osreleases_count = erratum.osreleases.count()
+        erratum.cves_count = erratum.cves.count()
+        erratum.references_count = erratum.references.count()
+        erratum.save(update_fields=[
+            'affected_packages_count',
+            'fixed_packages_count',
+            'osreleases_count',
+            'cves_count',
+            'references_count',
+        ])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('errata', '0008_add_cached_count_fields'),
+    ]
+
+    operations = [
+        migrations.RunPython(backfill_counts, migrations.RunPython.noop),
+    ]

errata/models.py

@@ -40,6 +40,11 @@ class Erratum(models.Model):
     osreleases = models.ManyToManyField(OSRelease, blank=True)
     cves = models.ManyToManyField(CVE, blank=True)
     references = models.ManyToManyField(Reference, blank=True)
+    affected_packages_count = models.PositiveIntegerField(default=0)
+    fixed_packages_count = models.PositiveIntegerField(default=0)
+    osreleases_count = models.PositiveIntegerField(default=0)
+    cves_count = models.PositiveIntegerField(default=0)
+    references_count = models.PositiveIntegerField(default=0)
 
     objects = ErratumManager()
 
@@ -49,9 +54,9 @@ class Meta:
         ordering = ['-issue_date', 'name']
 
     def __str__(self):
-        text = f'{self.name} ({self.e_type}), {self.cves.count()} related CVEs, '
-        text += f'affecting {self.osreleases.count()} OS Releases, '
-        text += f'providing {self.fixed_packages.count()} fixed Packages'
+        text = f'{self.name} ({self.e_type}), {self.cves_count} related CVEs, '
+        text += f'affecting {self.osreleases_count} OS Releases, '
+        text += f'providing {self.fixed_packages_count} fixed Packages'
         return text
 
     def get_absolute_url(self):

errata/signals.py

@@ -0,0 +1,60 @@
+# Copyright 2026 Marcus Furlong <furlongm@gmail.com>
+#
+# This file is part of Patchman.
+#
+# Patchman is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3 only.
+#
+# Patchman is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Patchman. If not, see <http://www.gnu.org/licenses/>
+
+from django.db.models.signals import m2m_changed
+from django.dispatch import receiver
+
+from errata.models import Erratum
+
+
+@receiver(m2m_changed, sender=Erratum.affected_packages.through)
+def update_affected_packages_count(sender, instance, action, **kwargs):
+    """Update affected_packages_count when Erratum.affected_packages M2M changes."""
+    if action in ('post_add', 'post_remove', 'post_clear'):
+        instance.affected_packages_count = instance.affected_packages.count()
+        instance.save(update_fields=['affected_packages_count'])
+
+
+@receiver(m2m_changed, sender=Erratum.fixed_packages.through)
+def update_fixed_packages_count(sender, instance, action, **kwargs):
+    """Update fixed_packages_count when Erratum.fixed_packages M2M changes."""
+    if action in ('post_add', 'post_remove', 'post_clear'):
+        instance.fixed_packages_count = instance.fixed_packages.count()
+        instance.save(update_fields=['fixed_packages_count'])
+
+
+@receiver(m2m_changed, sender=Erratum.osreleases.through)
+def update_osreleases_count(sender, instance, action, **kwargs):
+    """Update osreleases_count when Erratum.osreleases M2M changes."""
+    if action in ('post_add', 'post_remove', 'post_clear'):
+        instance.osreleases_count = instance.osreleases.count()
+        instance.save(update_fields=['osreleases_count'])
+
+
+@receiver(m2m_changed, sender=Erratum.cves.through)
+def update_cves_count(sender, instance, action, **kwargs):
+    """Update cves_count when Erratum.cves M2M changes."""
+    if action in ('post_add', 'post_remove', 'post_clear'):
+        instance.cves_count = instance.cves.count()
+        instance.save(update_fields=['cves_count'])
+
+
+@receiver(m2m_changed, sender=Erratum.references.through)
+def update_references_count(sender, instance, action, **kwargs):
+    """Update references_count when Erratum.references M2M changes."""
+    if action in ('post_add', 'post_remove', 'post_clear'):
+        instance.references_count = instance.references.count()
+        instance.save(update_fields=['references_count'])

errata/tables.py

@@ -19,31 +19,31 @@
 
 ERRATUM_NAME_TEMPLATE = '<a href="{{ record.get_absolute_url }}">{{ record.name }}</a>'
 PACKAGES_AFFECTED_TEMPLATE = (
-    '{% with count=record.affected_packages.count %}'
+    '{% with count=record.affected_packages_count %}'
     '{% if count != 0 %}'
     '<a href="{% url \'packages:package_list\' %}?erratum_id={{ record.id }}&type=affected">{{ count }}</a>'
     '{% else %}{% endif %}{% endwith %}'
 )
 PACKAGES_FIXED_TEMPLATE = (
-    '{% with count=record.fixed_packages.count %}'
+    '{% with count=record.fixed_packages_count %}'
     '{% if count != 0 %}'
     '<a href="{% url \'packages:package_list\' %}?erratum_id={{ record.id }}&type=fixed">{{ count }}</a>'
     '{% else %}{% endif %}{% endwith %}'
 )
 OSRELEASES_TEMPLATE = (
-    '{% with count=record.osreleases.count %}'
+    '{% with count=record.osreleases_count %}'
     '{% if count != 0 %}'
     '<a href="{% url \'operatingsystems:osrelease_list\' %}?erratum_id={{ record.id }}">{{ count }}</a>'
     '{% else %}{% endif %}{% endwith %}'
 )
 ERRATUM_CVES_TEMPLATE = (
-    '{% with count=record.cves.count %}'
+    '{% with count=record.cves_count %}'
     '{% if count != 0 %}'
     '<a href="{% url \'security:cve_list\' %}?erratum_id={{ record.id }}">{{ count }}</a>'
     '{% else %}{% endif %}{% endwith %}'
 )
 REFERENCES_TEMPLATE = (
-    '{% with count=record.references.count %}'
+    '{% with count=record.references_count %}'
     '{% if count != 0 %}'
     '<a href="{% url \'security:reference_list\' %}?erratum_id={{ record.id }}">{{ count }}</a>'
     '{% else %}{% endif %}{% endwith %}'

errata/templates/errata/erratum_detail.html

@@ -8,7 +8,7 @@
 
 {% block content %}
 
-{% with affected_count=erratum.affected_packages.count fixed_count=erratum.fixed_packages.count %}
+{% with affected_count=erratum.affected_packages_count fixed_count=erratum.fixed_packages_count %}
 <ul class="nav nav-tabs">
   <li class="active"><a data-toggle="tab" href="#erratum_details">Details</a></li>
   <li><a data-toggle="tab" href="#erratum_affected_packages">Packages Affected ({{ affected_count }})</a></li>

errata/tests/test_models.py

@@ -19,7 +19,7 @@
 
 from errata.models import Erratum
 from operatingsystems.models import OSRelease
-from security.models import CVE
+from security.models import CVE, Reference
 
 
 @override_settings(
@@ -120,3 +120,122 @@ def test_bugfix_erratum(self):
             issue_date=timezone.now(),
         )
         self.assertEqual(erratum.e_type, 'bugfix')
+
+
+@override_settings(
+    CELERY_TASK_ALWAYS_EAGER=True,
+    CACHES={'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
+)
+class ErratumCachedCountTests(TestCase):
+    """Tests for Erratum cached count fields and M2M signals."""
+
+    def setUp(self):
+        self.erratum = Erratum.objects.create(
+            name='USN-5678-1',
+            e_type='security',
+            synopsis='Security update',
+            issue_date=timezone.now(),
+        )
+
+    def test_initial_counts_are_zero(self):
+        """Test that cached counts start at zero."""
+        self.assertEqual(self.erratum.cves_count, 0)
+        self.assertEqual(self.erratum.osreleases_count, 0)
+        self.assertEqual(self.erratum.affected_packages_count, 0)
+        self.assertEqual(self.erratum.fixed_packages_count, 0)
+        self.assertEqual(self.erratum.references_count, 0)
+
+    def test_cves_count_on_add(self):
+        """Test cves_count increments on add."""
+        cve1 = CVE.objects.create(cve_id='CVE-2024-0001')
+        cve2 = CVE.objects.create(cve_id='CVE-2024-0002')
+        self.erratum.cves.add(cve1)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 1)
+        self.erratum.cves.add(cve2)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 2)
+
+    def test_cves_count_on_remove(self):
+        """Test cves_count decrements on remove."""
+        cve = CVE.objects.create(cve_id='CVE-2024-0003')
+        self.erratum.cves.add(cve)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 1)
+        self.erratum.cves.remove(cve)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 0)
+
+    def test_cves_count_on_clear(self):
+        """Test cves_count resets to zero on clear."""
+        cve1 = CVE.objects.create(cve_id='CVE-2024-0004')
+        cve2 = CVE.objects.create(cve_id='CVE-2024-0005')
+        self.erratum.cves.add(cve1, cve2)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 2)
+        self.erratum.cves.clear()
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, 0)
+
+    def test_osreleases_count_on_add(self):
+        """Test osreleases_count increments on add."""
+        release = OSRelease.objects.create(name='Ubuntu 24.04')
+        self.erratum.osreleases.add(release)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.osreleases_count, 1)
+
+    def test_osreleases_count_on_remove(self):
+        """Test osreleases_count decrements on remove."""
+        release = OSRelease.objects.create(name='Ubuntu 24.04')
+        self.erratum.osreleases.add(release)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.osreleases_count, 1)
+        self.erratum.osreleases.remove(release)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.osreleases_count, 0)
+
+    def test_references_count_on_add(self):
+        """Test references_count increments on add."""
+        ref = Reference.objects.create(
+            ref_type='ADVISORY',
+            url='https://example.com/advisory/1',
+        )
+        self.erratum.references.add(ref)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.references_count, 1)
+
+    def test_references_count_on_remove(self):
+        """Test references_count decrements on remove."""
+        ref = Reference.objects.create(
+            ref_type='ADVISORY',
+            url='https://example.com/advisory/2',
+        )
+        self.erratum.references.add(ref)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.references_count, 1)
+        self.erratum.references.remove(ref)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.references_count, 0)
+
+    def test_str_uses_cached_counts(self):
+        """Test __str__ reflects cached count values."""
+        cve = CVE.objects.create(cve_id='CVE-2024-0010')
+        release = OSRelease.objects.create(name='RHEL 9')
+        self.erratum.cves.add(cve)
+        self.erratum.osreleases.add(release)
+        self.erratum.refresh_from_db()
+        result = str(self.erratum)
+        self.assertIn('1 related CVEs', result)
+        self.assertIn('affecting 1 OS Releases', result)
+        self.assertIn('providing 0 fixed Packages', result)
+
+    def test_counts_match_actual_m2m(self):
+        """Test cached counts stay in sync with actual M2M counts."""
+        cve1 = CVE.objects.create(cve_id='CVE-2024-0020')
+        cve2 = CVE.objects.create(cve_id='CVE-2024-0021')
+        release = OSRelease.objects.create(name='Debian 12')
+        self.erratum.cves.add(cve1, cve2)
+        self.erratum.osreleases.add(release)
+        self.erratum.refresh_from_db()
+        self.assertEqual(self.erratum.cves_count, self.erratum.cves.count())
+        self.assertEqual(self.erratum.osreleases_count, self.erratum.osreleases.count())