zulip/zerver/migrations/0443_userpresence_new_table...

144 lines
5.6 KiB
Python

from typing import Any, Callable
import django.db.models.deletion
import django.utils.timezone
from django.conf import settings
from django.db import connection, migrations, models
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.migrations.state import StateApps
from psycopg2.sql import SQL, Identifier
def rename_indexes_constraints(
old_table: str, new_table: str
) -> Callable[[StateApps, BaseDatabaseSchemaEditor], None]:
def inner_migration(apps: StateApps, schema_editor: Any) -> None:
with connection.cursor() as cursor:
constraints = connection.introspection.get_constraints(cursor, old_table)
for old_name, infodict in constraints.items():
if infodict["check"]:
suffix = "_check"
is_index = False
elif infodict["foreign_key"] is not None:
is_index = False
to_table, to_column = infodict["foreign_key"]
suffix = f"_fk_{to_table}_{to_column}"
elif infodict["primary_key"]:
suffix = "_pk"
is_index = True
elif infodict["unique"]:
suffix = "_uniq"
is_index = True
else:
suffix = "_idx" if len(infodict["columns"]) > 1 else ""
is_index = True
new_name = schema_editor._create_index_name(new_table, infodict["columns"], suffix)
if is_index:
raw_query = SQL("ALTER INDEX {old_name} RENAME TO {new_name}").format(
old_name=Identifier(old_name), new_name=Identifier(new_name)
)
else:
raw_query = SQL(
"ALTER TABLE {old_table} RENAME CONSTRAINT {old_name} TO {new_name}"
).format(
old_table=Identifier(old_table),
old_name=Identifier(old_name),
new_name=Identifier(new_name),
)
cursor.execute(raw_query)
for infodict in connection.introspection.get_sequences(cursor, old_table):
old_name = infodict["name"]
column = infodict["column"]
new_name = f"{new_table}_{column}_seq"
raw_query = SQL("ALTER SEQUENCE {old_name} RENAME TO {new_name}").format(
old_name=Identifier(old_name),
new_name=Identifier(new_name),
)
cursor.execute(raw_query)
cursor.execute(
SQL("ALTER TABLE {old_table} RENAME TO {new_table}").format(
old_table=Identifier(old_table), new_table=Identifier(new_table)
)
)
return inner_migration
class Migration(migrations.Migration):
"""
First step of migrating to a new UserPresence data model. Creates a new
table with the intended fields, into which in the next step
data can be ported over from the current UserPresence model.
In the last step, the old model will be replaced with the new one.
"""
dependencies = [
("zerver", "0442_remove_realmfilter_url_format_string"),
]
operations = [
# Django doesn't rename indexes and constraints when renaming
# a table (https://code.djangoproject.com/ticket/23577). This
# means that after renaming UserPresence->UserPresenceOld the
# UserPresenceOld indexes/constraints retain their old name
# causing a conflict when CreateModel tries to create them for
# the new UserPresence table.
migrations.SeparateDatabaseAndState(
database_operations=[
migrations.RunPython(
rename_indexes_constraints("zerver_userpresence", "zerver_userpresenceold"),
reverse_code=rename_indexes_constraints(
"zerver_userpresenceold", "zerver_userpresence"
),
)
],
state_operations=[
migrations.RenameModel(
old_name="UserPresence",
new_name="UserPresenceOld",
)
],
),
migrations.CreateModel(
name="UserPresence",
fields=[
(
"id",
models.AutoField(
auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
),
),
(
"last_connected_time",
models.DateTimeField(
db_index=True, default=django.utils.timezone.now, null=True
),
),
(
"last_active_time",
models.DateTimeField(
db_index=True, default=django.utils.timezone.now, null=True
),
),
(
"realm",
models.ForeignKey(
on_delete=django.db.models.deletion.CASCADE, to="zerver.Realm"
),
),
(
"user_profile",
models.OneToOneField(
on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL
),
),
],
options={
"index_together": {("realm", "last_active_time"), ("realm", "last_connected_time")},
},
),
]