A ChatGPT script for testing

Dockerfile

@@ -32,7 +32,7 @@ RUN set -eux \
 # Purpose: Installs s6-overlay and rootfs
 # Comments:
 #  - Don't leave anything extra in here either
-FROM ghcr.io/astral-sh/uv:0.9.17-python3.12-trixie-slim AS s6-overlay-base
+FROM ghcr.io/astral-sh/uv:0.9.15-python3.12-trixie-slim AS s6-overlay-base
 
 WORKDIR /usr/src/s6
 

scripts/tag_perf_probe.py

@@ -0,0 +1,139 @@
+# noqa: INP001
+
+"""
+Ad-hoc script to gauge Tag + treenode performance locally.
+
+It bootstraps a fresh SQLite DB in a temp folder (or PAPERLESS_DATA_DIR),
+uses locmem cache/redis to avoid external services, creates synthetic tags,
+and measures:
+ - creation time
+ - query count and wall time for the Tag list view
+
+Usage:
+    PAPERLESS_DEBUG=1 PAPERLESS_REDIS=locmem:// PYTHONPATH=src \
+    PAPERLESS_DATA_DIR=/tmp/paperless-tags-probe \
+    .venv/bin/python scripts/tag_perf_probe.py
+"""
+
+import os
+import sys
+import time
+from collections.abc import Iterable
+from contextlib import contextmanager
+
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "paperless.settings")
+os.environ.setdefault("PAPERLESS_DEBUG", "1")
+os.environ.setdefault("PAPERLESS_REDIS", "locmem://")
+os.environ.setdefault("PYTHONPATH", "src")
+
+import django
+
+django.setup()
+
+from django.contrib.auth import get_user_model  # noqa: E402
+from django.core.management import call_command  # noqa: E402
+from django.db import connection  # noqa: E402
+from django.test.client import RequestFactory  # noqa: E402
+from rest_framework.test import force_authenticate  # noqa: E402
+from treenode.signals import no_signals  # noqa: E402
+
+from documents.models import Tag  # noqa: E402
+from documents.views import TagViewSet  # noqa: E402
+
+User = get_user_model()
+
+
+@contextmanager
+def count_queries():
+    total = 0
+
+    def wrapper(execute, sql, params, many, context):
+        nonlocal total
+        total += 1
+        return execute(sql, params, many, context)
+
+    with connection.execute_wrapper(wrapper):
+        yield lambda: total
+
+
+def measure_list(tag_count: int, user) -> tuple[int, float]:
+    """Render Tag list with page_size=tag_count and return (queries, seconds)."""
+    rf = RequestFactory()
+    view = TagViewSet.as_view({"get": "list"})
+    request = rf.get("/api/tags/", {"page_size": tag_count})
+    force_authenticate(request, user=user)
+
+    with count_queries() as get_count:
+        start = time.perf_counter()
+        response = view(request)
+        response.render()
+        elapsed = time.perf_counter() - start
+        total_queries = get_count()
+
+    return total_queries, elapsed
+
+
+def bulk_create_tags(count: int, parents: Iterable[Tag] | None = None) -> None:
+    """Create tags; when parents provided, create one child per parent."""
+    if parents is None:
+        Tag.objects.bulk_create([Tag(name=f"Flat {i}") for i in range(count)])
+        return
+
+    children = []
+    for p in parents:
+        children.append(Tag(name=f"Child {p.id}", tn_parent=p))
+    Tag.objects.bulk_create(children)
+
+
+def run():
+    # Ensure tables exist when pointing at a fresh DATA_DIR.
+    call_command("migrate", interactive=False, verbosity=0)
+
+    user, _ = User.objects.get_or_create(
+        username="admin",
+        defaults={"is_superuser": True, "is_staff": True},
+    )
+
+    # Flat scenario
+    Tag.objects.all().delete()
+    start = time.perf_counter()
+    bulk_create_tags(200)
+    flat_create = time.perf_counter() - start
+    q, t = measure_list(tag_count=200, user=user)
+    print(f"Flat create 200 -> {flat_create:.2f}s; list -> {q} queries, {t:.2f}s")  # noqa: T201
+
+    # Nested scenario (parents + 2 children each => 600 total)
+    Tag.objects.all().delete()
+    start = time.perf_counter()
+    with no_signals():  # avoid per-save tree rebuild; rebuild once
+        parents = Tag.objects.bulk_create([Tag(name=f"Parent {i}") for i in range(200)])
+        children = []
+        for p in parents:
+            children.extend(
+                Tag(name=f"Child {p.id}-{j}", tn_parent=p) for j in range(2)
+            )
+        Tag.objects.bulk_create(children)
+    Tag.update_tree()
+    nested_create = time.perf_counter() - start
+    q, t = measure_list(tag_count=600, user=user)
+    print(f"Nested create 600 -> {nested_create:.2f}s; list -> {q} queries, {t:.2f}s")  # noqa: T201
+
+    # Larger nested scenario (1 child per parent, 3000 total)
+    Tag.objects.all().delete()
+    start = time.perf_counter()
+    with no_signals():
+        parents = Tag.objects.bulk_create(
+            [Tag(name=f"Parent {i}") for i in range(1500)],
+        )
+        bulk_create_tags(0, parents=parents)
+    Tag.update_tree()
+    big_create = time.perf_counter() - start
+    q, t = measure_list(tag_count=3000, user=user)
+    print(f"Nested create 3000 -> {big_create:.2f}s; list -> {q} queries, {t:.2f}s")  # noqa: T201
+
+
+if __name__ == "__main__":
+    if "runserver" in sys.argv:
+        print("Run directly: .venv/bin/python scripts/tag_perf_probe.py")  # noqa: T201
+        sys.exit(1)
+    run()

src/documents/apps.py

@@ -1,5 +1,9 @@
 from django.apps import AppConfig
+from django.db.models.signals import post_delete
+from django.db.models.signals import post_save
 from django.utils.translation import gettext_lazy as _
+from treenode.signals import post_delete_treenode
+from treenode.signals import post_save_treenode
 
 
 class DocumentsConfig(AppConfig):
@@ -8,12 +12,14 @@ class DocumentsConfig(AppConfig):
     verbose_name = _("Documents")
 
     def ready(self):
+        from documents.models import Tag
         from documents.signals import document_consumption_finished
         from documents.signals import document_updated
         from documents.signals.handlers import add_inbox_tags
         from documents.signals.handlers import add_to_index
         from documents.signals.handlers import run_workflows_added
         from documents.signals.handlers import run_workflows_updated
+        from documents.signals.handlers import schedule_tag_tree_update
         from documents.signals.handlers import set_correspondent
         from documents.signals.handlers import set_document_type
         from documents.signals.handlers import set_storage_path
@@ -28,6 +34,29 @@ class DocumentsConfig(AppConfig):
         document_consumption_finished.connect(run_workflows_added)
         document_updated.connect(run_workflows_updated)
 
+        # treenode updates the entire tree on every save/delete via hooks
+        # so disconnect for Tags and run once-per-transaction.
+        post_save.disconnect(
+            post_save_treenode,
+            sender=Tag,
+            dispatch_uid="post_save_treenode",
+        )
+        post_delete.disconnect(
+            post_delete_treenode,
+            sender=Tag,
+            dispatch_uid="post_delete_treenode",
+        )
+        post_save.connect(
+            schedule_tag_tree_update,
+            sender=Tag,
+            dispatch_uid="paperless_tag_mark_dirty_save",
+        )
+        post_delete.connect(
+            schedule_tag_tree_update,
+            sender=Tag,
+            dispatch_uid="paperless_tag_mark_dirty_delete",
+        )
+
         import documents.schema  # noqa: F401
 
         AppConfig.ready(self)

src/documents/serialisers.py

@@ -578,30 +578,34 @@ class TagSerializer(MatchingModelSerializer, OwnedObjectSerializer):
         ),
     )
     def get_children(self, obj):
-        filter_q = self.context.get("document_count_filter")
-        request = self.context.get("request")
-        if filter_q is None:
-            user = getattr(request, "user", None) if request else None
-            filter_q = get_document_count_filter_for_user(user)
-            self.context["document_count_filter"] = filter_q
+        children_map = self.context.get("children_map")
+        if children_map is not None:
+            children = children_map.get(obj.pk, [])
+        else:
+            filter_q = self.context.get("document_count_filter")
+            request = self.context.get("request")
+            if filter_q is None:
+                user = getattr(request, "user", None) if request else None
+                filter_q = get_document_count_filter_for_user(user)
+                self.context["document_count_filter"] = filter_q
 
-        children_queryset = (
-            obj.get_children_queryset()
-            .select_related("owner")
-            .annotate(document_count=Count("documents", filter=filter_q))
-        )
+            children = (
+                obj.get_children_queryset()
+                .select_related("owner")
+                .annotate(document_count=Count("documents", filter=filter_q))
+            )
 
-        view = self.context.get("view")
-        ordering = (
-            OrderingFilter().get_ordering(request, children_queryset, view)
-            if request and view
-            else None
-        )
-        ordering = ordering or (Lower("name"),)
-        children_queryset = children_queryset.order_by(*ordering)
+            view = self.context.get("view")
+            ordering = (
+                OrderingFilter().get_ordering(request, children, view)
+                if request and view
+                else None
+            )
+            ordering = ordering or (Lower("name"),)
+            children = children.order_by(*ordering)
 
         serializer = TagSerializer(
-            children_queryset,
+            children,
             many=True,
             user=self.user,
             full_perms=self.full_perms,

src/documents/signals/handlers.py

@@ -19,6 +19,7 @@ from django.db import DatabaseError
 from django.db import close_old_connections
 from django.db import connections
 from django.db import models
+from django.db import transaction
 from django.db.models import Q
 from django.dispatch import receiver
 from django.utils import timezone
@@ -60,6 +61,8 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger("paperless.handlers")
 
+_tag_tree_update_scheduled = False
+
 
 def add_inbox_tags(sender, document: Document, logging_group=None, **kwargs):
     if document.owner is not None:
@@ -944,3 +947,26 @@ def close_connection_pool_on_worker_init(**kwargs):
     for conn in connections.all(initialized_only=True):
         if conn.alias == "default" and hasattr(conn, "pool") and conn.pool:
             conn.close_pool()
+
+
+def schedule_tag_tree_update(**_kwargs):
+    """
+    Schedule a single Tag.update_tree() at transaction commit.
+
+    Treenode's default post_save hooks rebuild the entire tree on every save,
+    which is very slow for large tag sets so collapse to one update per
+    transaction.
+    """
+    global _tag_tree_update_scheduled
+    if _tag_tree_update_scheduled:
+        return
+    _tag_tree_update_scheduled = True
+
+    def _run():
+        global _tag_tree_update_scheduled
+        try:
+            Tag.update_tree()
+        finally:
+            _tag_tree_update_scheduled = False
+
+    transaction.on_commit(_run)

src/documents/tests/test_tag_hierarchy.py

@@ -250,3 +250,16 @@ class TestTagHierarchy(APITestCase):
             row for row in response.data["results"] if row["id"] == self.parent.pk
         )
         assert any(child["id"] == self.child.pk for child in parent_entry["children"])
+
+    def test_tag_tree_deferred_update_runs_on_commit(self):
+        from django.db import transaction
+
+        # Create tags inside an explicit transaction and commit.
+        with transaction.atomic():
+            parent = Tag.objects.create(name="Parent 2")
+            child = Tag.objects.create(name="Child 2", tn_parent=parent)
+        # After commit, tn_* fields should be populated.
+        parent.refresh_from_db()
+        child.refresh_from_db()
+        assert parent.tn_children_count == 1
+        assert child.tn_ancestors_count == 1

src/documents/views.py

@@ -448,8 +448,43 @@ class TagViewSet(ModelViewSet, PermissionsAwareDocumentCountMixin):
     def get_serializer_context(self):
         context = super().get_serializer_context()
         context["document_count_filter"] = self.get_document_count_filter()
+        if hasattr(self, "_children_map"):
+            context["children_map"] = self._children_map
         return context
 
+    def list(self, request, *args, **kwargs):
+        """
+        Build a children map once to avoid per-parent queries in the serializer.
+        """
+        queryset = self.filter_queryset(self.get_queryset())
+        ordering = OrderingFilter().get_ordering(request, queryset, self) or (
+            Lower("name"),
+        )
+        queryset = queryset.order_by(*ordering)
+
+        all_tags = list(queryset)
+        descendant_pks = {pk for tag in all_tags for pk in tag.get_descendants_pks()}
+
+        if descendant_pks:
+            filter_q = self.get_document_count_filter()
+            children_source = (
+                Tag.objects.filter(pk__in=descendant_pks | {t.pk for t in all_tags})
+                .select_related("owner")
+                .annotate(document_count=Count("documents", filter=filter_q))
+                .order_by(*ordering)
+            )
+        else:
+            children_source = all_tags
+
+        children_map = {}
+        for tag in children_source:
+            children_map.setdefault(tag.tn_parent_id, []).append(tag)
+        self._children_map = children_map
+
+        page = self.paginate_queryset(queryset)
+        serializer = self.get_serializer(page, many=True)
+        return self.get_paginated_response(serializer.data)
+
     def perform_update(self, serializer):
         old_parent = self.get_object().get_parent()
         tag = serializer.save()