New show_references_index management command

wagtail/management/commands/show_references_index.py

@@ -0,0 +1,36 @@
+from django.apps import apps
+from django.contrib.contenttypes.models import ContentType
+from django.core.management.base import BaseCommand
+
+from wagtail.models import ReferenceIndex
+
+
+def model_name(model):
+    return f"{model.__module__}.{model.__name__}"
+
+
+class Command(BaseCommand):
+    def handle(self, **options):
+        self.stdout.write("Reference index entries:")
+        object_count = 0
+
+        for model in sorted(apps.get_models(), key=lambda m: model_name(m)):
+            if not ReferenceIndex.is_indexed(model):
+                continue
+
+            content_types = [
+                ContentType.objects.get_for_model(
+                    model_or_object, for_concrete_model=False
+                )
+                for model_or_object in ([model] + model._meta.get_parent_list())
+            ]
+            content_type = content_types[0]
+            base_content_type = content_types[-1]
+
+            count = ReferenceIndex.objects.filter(
+                content_type=content_type, base_content_type=base_content_type
+            ).count()
+            self.stdout.write(f"{count:>6}  {model_name(model)}")
+            object_count += count
+
+        self.stdout.write(f"Total entries: {object_count}")