'get_or_create_direct_message_group' is used inside an outer
db transaction created in 'edit_scheduled_message'.
`transaction.atomic()` block in 'get_or_create_direct_message_group'
resulted in savepoint creation.
This commit adds `savepoint=False` to avoid that.
This commit adds a new `group_size` field to the `DirectMessageGroup`
model, and backfills its value to each of the existing direct message
groups.
Fixes part of #25713
This commit renames the "Huddle" Django model class to
"DirectMessageGroup", while maintaining the same table --
"zerver_huddle".
Fixes part of #28640.
This commit performs a sweep on the first batch of non API
files to rename "huddle" to "direct_message_group`.
It also renames variables and methods of type -
"huddle_message" to "group_direct_message".
This is a part of #28640
Migrate all `ids` of anything which does not have a foreign key from
the Message or UserMessage table (and would thus require walking
those) to be `bigint`. This is done by removing explicit
`BigAutoField`s, trading them for explicit `AutoField`s on the tables
to not be migrated, while updating `DEFAULT_AUTO_FIELD` to the new
default.
In general, the tables adjusted in this commit are small tables -- at
least compared to Messages and UserMessages.
Many-to-many tables without their own model class are adjusted by a
custom Operation, since they do not automatically pick up migrations
when `DEFAULT_AUTO_FIELD` changes[^1].
Note that this does multiple scans over tables to update foreign
keys[^2]. Large installs may wish to hand-optimize this using the
output of `./manage.py sqlmigrate` to join multiple `ALTER TABLE`
statements into one, to speed up the migration. This is unfortunately
not possible to do generically, as constraint names may differ between
installations.
This leaves the following primary keys as non-`bigint`:
- `auth_group.id`
- `auth_group_permissions.id`
- `auth_permission.id`
- `django_content_type.id`
- `django_migrations.id`
- `otp_static_staticdevice.id`
- `otp_static_statictoken.id`
- `otp_totp_totpdevice.id`
- `two_factor_phonedevice.id`
- `zerver_archivedmessage.id`
- `zerver_client.id`
- `zerver_message.id`
- `zerver_realm.id`
- `zerver_recipient.id`
- `zerver_userprofile.id`
[^1]: https://code.djangoproject.com/ticket/32674
[^2]: https://code.djangoproject.com/ticket/24203
Replaced HUDDLE attribute with DIRECT_MESSAGE_GROUP using VS Code search,
part of a general renaming of the object class.
Fixes part of #28640.
Co-authored-by: JohnLu2004 <JohnLu10212004@gmail.com>