retention: Add .restored_timestamp to ArchiveTransaction.

This is just generally useful for tracking and debugging.

zerver/lib/retention.py

@@ -587,6 +587,7 @@ def restore_data_from_archive(archive_transaction: ArchiveTransaction) -> int:
         restore_attachment_messages_from_archive(archive_transaction.id)
 
         archive_transaction.restored = True
+        archive_transaction.restored_timestamp = timezone_now()
         archive_transaction.save()
 
     logger.info("Finished. Restored %s messages", len(msg_ids))

zerver/migrations/0519_archivetransaction_restored_timestamp.py

@@ -0,0 +1,17 @@
+# Generated by Django 5.0.6 on 2024-05-08 00:59
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0518_merge"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="archivetransaction",
+            name="restored_timestamp",
+            field=models.DateTimeField(db_index=True, null=True),
+        ),
+    ]

zerver/models/messages.py

@@ -91,6 +91,7 @@ class ArchiveTransaction(models.Model):
     timestamp = models.DateTimeField(default=timezone_now, db_index=True)
     # Marks if the data archived in this transaction has been restored:
     restored = models.BooleanField(default=False, db_index=True)
+    restored_timestamp = models.DateTimeField(null=True, db_index=True)
 
     type = models.PositiveSmallIntegerField(db_index=True)
     # Valid types:

zerver/tests/test_retention.py

@@ -2,6 +2,7 @@ from datetime import datetime, timedelta
 from typing import Any, Dict, List, Optional, Tuple
 from unittest import mock
 
+import time_machine
 from django.conf import settings
 from django.utils.timezone import now as timezone_now
 from typing_extensions import override
@@ -466,11 +467,15 @@ class TestArchiveMessagesGeneral(ArchiveMessagesTestingBase):
         transactions = ArchiveTransaction.objects.all()
         self.assert_length(transactions, 2)  # With chunk_size 4, there should be 2 transactions
 
-        restore_all_data_from_archive()
+        now = timezone_now()
+        with time_machine.travel(now, tick=False):
+            restore_all_data_from_archive()
         transactions[0].refresh_from_db()
         transactions[1].refresh_from_db()
         self.assertTrue(transactions[0].restored)
         self.assertTrue(transactions[1].restored)
+        self.assertEqual(transactions[0].restored_timestamp, now)
+        self.assertEqual(transactions[1].restored_timestamp, now)
 
         archive_messages(chunk_size=10)
         self._verify_archive_data(expired_msg_ids, expired_usermsg_ids)