snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/migrations/0257_fix_has_link_attribute.py

@@ -0,0 +1,93 @@
+# Generated by Django 1.11.24 on 2019-10-07 05:25
+
+import time
+from typing import cast
+
+import lxml
+from django.db import migrations
+from django.db.backends.base.schema import BaseDatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+
+BATCH_SIZE = 1000
+
+
+def process_batch(apps: StateApps, id_start: int, id_end: int, last_id: int) -> None:
+    Message = apps.get_model("zerver", "Message")
+    for message in Message.objects.filter(id__gte=id_start, id__lte=id_end).order_by("id"):
+        if message.rendered_content in ["", None]:
+            # There have been bugs in the past that made it possible
+            # for a message to have "" or None as its rendered_content; we
+            # need to skip those because lxml won't process them.
+            #
+            # They should safely already have the correct state
+            #   has_link=has_image=has_attachment=False.
+            continue
+
+        if message.id % 1000 == 0:
+            print(f"Processed {message.id} / {last_id}")
+
+        # Because we maintain the Attachment table, this should be as
+        # simple as just checking if there's any Attachment
+        # objects associated with this message.
+        has_attachment = message.attachment_set.exists()
+
+        # For has_link and has_image, we need to parse the messages.
+        # Links are simple -- look for a link in the message.
+        lxml_obj = lxml.html.fromstring(message.rendered_content)
+        has_link = any(True for link in lxml_obj.iter("a"))
+
+        # has_image refers to inline image previews, so we just check
+        # for the relevant CSS class.
+        has_image = any(
+            True for img in cast(lxml.html.HtmlMixin, lxml_obj).find_class("message_inline_image")
+        )
+
+        if (
+            message.has_link == has_link
+            and message.has_attachment == has_attachment
+            and message.has_image == has_image
+        ):
+            # No need to spend time with the database if there aren't changes.
+            continue
+        message.has_image = has_image
+        message.has_link = has_link
+        message.has_attachment = has_attachment
+        message.save(update_fields=["has_link", "has_attachment", "has_image"])
+
+
+def fix_has_link(apps: StateApps, schema_editor: BaseDatabaseSchemaEditor) -> None:
+    Message = apps.get_model("zerver", "Message")
+    if not Message.objects.exists():
+        # Nothing to do, and Message.objects.latest() will crash.
+        return
+
+    # This migration logic assumes that either the server is not
+    # running, or that it's being run after the logic to correct how
+    # `has_link` and friends are set for new messages have been
+    # deployed.
+    last_id = Message.objects.latest("id").id
+
+    id_range_lower_bound = 0
+    id_range_upper_bound = 0 + BATCH_SIZE
+    while id_range_upper_bound <= last_id:
+        process_batch(apps, id_range_lower_bound, id_range_upper_bound, last_id)
+
+        id_range_lower_bound = id_range_upper_bound + 1
+        id_range_upper_bound = id_range_lower_bound + BATCH_SIZE
+        time.sleep(0.1)
+
+    if last_id > id_range_lower_bound:
+        # Copy for the last batch.
+        process_batch(apps, id_range_lower_bound, last_id, last_id)
+
+
+class Migration(migrations.Migration):
+    atomic = False
+
+    dependencies = [
+        ("zerver", "0256_userprofile_stream_set_recipient_column_values"),
+    ]
+
+    operations = [
+        migrations.RunPython(fix_has_link, reverse_code=migrations.RunPython.noop, elidable=True),
+    ]