Data model for transactional history (#2147)

src/pretix/base/models/_transactions.py

@@ -0,0 +1,99 @@
+#
+# This file is part of pretix (Community Edition).
+#
+# Copyright (C) 2014-2020 Raphael Michel and contributors
+# Copyright (C) 2020-2021 rami.io GmbH and contributors
+#
+# This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General
+# Public License as published by the Free Software Foundation in version 3 of the License.
+#
+# ADDITIONAL TERMS APPLY: Pursuant to Section 7 of the GNU Affero General Public License, additional terms are
+# applicable granting you additional permissions and placing additional restrictions on your usage of this software.
+# Please refer to the pretix LICENSE file to obtain the full terms applicable to this work. If you did not receive
+# this file, see <https://pretix.eu/about/en/license>.
+#
+# This program 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 Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along with this program.  If not, see
+# <https://www.gnu.org/licenses/>.
+#
+
+"""
+This module contains helper functions that are supposed to call out code paths missing calls to
+``Order.create_transaction()`` by actively breaking them. Read the docstring of the ``Transaction`` class for a
+detailed reasoning why this exists.
+"""
+import inspect
+import logging
+import os
+import threading
+
+from django.db import transaction
+
+dirty_transactions = threading.local()
+
+logger = logging.getLogger(__name__)
+fail_loudly = os.getenv('PRETIX_DIRTY_TRANSACTIONS_QUIET', 'false') not in ('true', 'True', 'on', '1')
+
+
+class DirtyTransactionsForOrderException(Exception):
+    pass
+
+
+def _fail(message):
+    if fail_loudly:
+        raise DirtyTransactionsForOrderException(message)
+    else:
+        logger.warning(message, stack_info=True)
+
+
+def _check_for_dirty_orders():
+    if getattr(dirty_transactions, 'order_ids', None) is None:
+        dirty_transactions.order_ids = set()
+    if not dirty_transactions.order_ids and dirty_transactions.order_ids != {None}:
+        _fail(
+            "In the transaction that just ended, you created or modified an Order, OrderPosition, or OrderFee "
+            "object in a way that you should have called `order.create_transactions()` afterwards. The transaction "
+            "still went through and your data can be fixed with the `create_order_transactions` management command "
+            "but you should update your code to prevent this from happening."
+        )
+    dirty_transactions.order_ids.clear()
+
+
+def _transactions_mark_order_dirty(order_id, using=None):
+    if "PYTEST_CURRENT_TEST" in os.environ:
+        # We don't care about Order.objects.create() calls in test code so let's try to figure out if this is test code
+        # or not.
+        for frame in inspect.stack():
+            if 'pretix/base/models/orders' in frame.filename:
+                continue
+            elif 'test_' in frame.filename or 'conftest.py in frame.filename':
+                return
+            elif 'pretix/' in frame.filename or 'pretix_' in frame.filename:
+                # This went through non-test code, let's consider it non-test
+                break
+
+    if getattr(dirty_transactions, 'order_ids', None) is None:
+        dirty_transactions.order_ids = set()
+    dirty_transactions.order_ids.add(order_id)
+    conn = transaction.get_connection(using)
+    if not conn.in_atomic_block:
+        _fail(
+            "You modified an Order, OrderPosition, or OrderFee object in a way that should create "
+            "a new Transaction object within the same database transaction, however you are not "
+            "doing it inside a database transaction!"
+        )
+
+    if _check_for_dirty_orders not in [func for savepoint_id, func in conn.run_on_commit]:
+        transaction.on_commit(_check_for_dirty_orders, using)
+
+
+def _transactions_mark_order_clean(order_id):
+    if getattr(dirty_transactions, 'order_ids', None) is None:
+        dirty_transactions.order_ids = set()
+    try:
+        dirty_transactions.order_ids.remove(order_id)
+    except KeyError:
+        pass