Use db.execute_isolated_fn() to run VACUUM, if available

[simonw]

See:

• Mechanism for executing "isolated" database operations without prepared connection stuff datasette#2218

To recap: plugins like https://github.com/datasette/datasette-sqlite-authorizer could result in a situation where running VACUUM against the standard Datasette write connection fails, because an authorizer prevents the required updates to one of the tables in the database.

To resolve this, Datasette now has a db.execute_isolated_fn() method which skips the prepare_connection() plugin hooks that could have added such an authorizer.

This will be a feature in Datasette 1.0, so to use it here we can use hasattr(database, "execute_isolated_fn"):

datasette-edit-schema/datasette_edit_schema/__init__.py

Lines 556 to 561 in 542495a

	async def drop_table(request, datasette, database, table):
	def do_drop_table(conn):
	db = sqlite_utils.Database(conn)
	db[table].disable_fts()
	db[table].drop()
	db.vacuum()