optimization of AttachmentInline

preventing iteration over all attachments in database

post_office/admin.py

@@ -17,7 +17,6 @@
 from django.utils.translation import gettext_lazy as _
 
 from .fields import CommaSeparatedEmailField
-from .mail import send
 from .models import STATUS, Attachment, Email, EmailTemplate, Log
 from .sanitizer import clean_html
 
@@ -34,6 +33,7 @@ class AttachmentInline(admin.StackedInline):
     model = Attachment.emails.through
     extra = 0
     autocomplete_fields = ["attachment"]
+    parent_obj = None
 
     def get_formset(self, request, obj=None, **kwargs):
         self.parent_obj = obj
@@ -48,13 +48,9 @@ def get_queryset(self, request):
         if self.parent_obj:
             queryset = queryset.filter(email=self.parent_obj)
 
-        inlined_attachments = [
-            a.id
-            for a in queryset
-            if isinstance(a.attachment.headers, dict)
-            and a.attachment.headers.get("Content-Disposition", "").startswith("inline")
-        ]
-        return queryset.exclude(id__in=inlined_attachments)
+        return queryset.exclude(
+            **{"attachment__headers__Content-Disposition__startswith": "inline"}
+        )
 
 
 class LogInline(admin.TabularInline):

post_office/migrations/0001_initial.py

@@ -38,8 +38,8 @@ class Migration(migrations.Migration):
                 ('created', models.DateTimeField(auto_now_add=True, db_index=True)),
                 ('last_updated', models.DateTimeField(auto_now=True, db_index=True)),
                 ('scheduled_time', models.DateTimeField(db_index=True, null=True, blank=True)),
-                ('headers', models.JSONField(null=True, blank=True)),
-                ('context', models.JSONField(null=True, blank=True)),
+                ('headers', models.TextField(null=True, blank=True)),
+                ('context', models.TextField(null=True, blank=True)),
             ],
             options={
             },

post_office/migrations/0004_auto_20160607_0901.py

@@ -47,12 +47,12 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name='email',
             name='context',
-            field=models.JSONField(blank=True, null=True, verbose_name='Context'),
+            field=models.TextField(blank=True, null=True, verbose_name='Context'),
         ),
         migrations.AlterField(
             model_name='email',
             name='headers',
-            field=models.JSONField(blank=True, null=True, verbose_name='Headers'),
+            field=models.TextField(blank=True, null=True, verbose_name='Headers'),
         ),
         migrations.AlterField(
             model_name='email',

post_office/migrations/0008_attachment_headers.py

@@ -12,6 +12,6 @@ class Migration(migrations.Migration):
         migrations.AddField(
             model_name='attachment',
             name='headers',
-            field=models.JSONField(blank=True, null=True, verbose_name='Headers'),
+            field=models.TextField(blank=True, null=True, verbose_name='Headers'),
         ),
     ]

post_office/migrations/0012_jsonfield.py

@@ -0,0 +1,27 @@
+# Generated by Django 3.2.15 on 2022-09-14 15:45
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("post_office", "0011_models_help_text"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="attachment",
+            name="headers",
+            field=models.JSONField(blank=True, null=True, verbose_name="Headers"),
+        ),
+        migrations.AlterField(
+            model_name="email",
+            name="context",
+            field=models.JSONField(blank=True, null=True, verbose_name="Context"),
+        ),
+        migrations.AlterField(
+            model_name="email",
+            name="headers",
+            field=models.JSONField(blank=True, null=True, verbose_name="Headers"),
+        ),
+    ]