fix: make database async

core/data/alembic/env.py

@@ -1,8 +1,14 @@
 from __future__ import with_statement
-from alembic import context
-from sqlalchemy import engine_from_config, pool
+
+import asyncio
+import threading
 from logging.config import fileConfig
 
+from alembic import context
+from sqlalchemy import pool
+from sqlalchemy.engine import Connection
+from sqlalchemy.ext.asyncio import async_engine_from_config
+
 from core.data.schema.base import metadata
 
 # this is the Alembic Config object, which provides
@@ -37,20 +43,29 @@ def run_migrations_offline():
     script output.
 
     """
-    raise Exception('Not implemented or configured!')
+    raise Exception("Not implemented or configured!")
 
     url = config.get_main_option("sqlalchemy.url")
-    context.configure(
-        url=url, target_metadata=target_metadata, literal_binds=True)
+    context.configure(url=url, target_metadata=target_metadata, literal_binds=True)
 
     with context.begin_transaction():
         context.run_migrations()
 
 
-def run_migrations_online():
-    """Run migrations in 'online' mode.
+def do_run_migrations(connection: Connection) -> None:
+    context.configure(
+        connection=connection,
+        target_metadata=target_metadata,
+        compare_type=True,
+        compare_server_default=True,
+    )
 
-    In this scenario we need to create an Engine
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations() -> None:
+    """In this scenario we need to create an Engine
     and associate a connection with the context.
 
     """
@@ -59,21 +74,32 @@ def run_migrations_online():
     for override in overrides:
         ini_section[override] = overrides[override]
 
-    connectable = engine_from_config(
-        ini_section,
-        prefix='sqlalchemy.',
-        poolclass=pool.NullPool)
+    connectable = async_engine_from_config(
+        ini_section, prefix="sqlalchemy.", poolclass=pool.NullPool
+    )
 
-    with connectable.connect() as connection:
-        context.configure(
-            connection=connection,
-            target_metadata=target_metadata,
-            compare_type=True,
-            compare_server_default=True,
-        )
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+def run_migrations_online():
+    try:
+        loop = asyncio.get_running_loop()
+    except RuntimeError:
+        # there's no event loop
+        asyncio.run(run_async_migrations())
+    else:
+        # there's currently an event loop and trying to wait for a coroutine
+        # to finish without using `await` is pretty wormy. nested event loops
+        # are explicitly forbidden by asyncio.
+        #
+        # take the easy way out, spawn it in another thread.
+        thread = threading.Thread(target=asyncio.run, args=(run_async_migrations(),))
+        thread.start()
+        thread.join()
 
-        with context.begin_transaction():
-            context.run_migrations()
 
 if context.is_offline_mode():
     run_migrations_offline()