rewrite: New data ORM.

bot/data/connector.py

@@ -0,0 +1,58 @@
+from typing import Protocol, runtime_checkable, Callable, Awaitable
+import logging
+
+import psycopg as psq
+
+from .cursor import AsyncLoggingCursor
+
+logger = logging.getLogger(__name__)
+
+row_factory = psq.rows.dict_row
+
+
+class Connector:
+    cursor_factory = AsyncLoggingCursor
+
+    def __init__(self, conn_args):
+        self._conn_args = conn_args
+        self.conn: psq.AsyncConnection = None
+
+        self.conn_hooks = []
+
+    async def get_connection(self) -> psq.AsyncConnection:
+        """
+        Get the current active connection.
+        This should never be cached outside of a transaction.
+        """
+        # TODO: Reconnection logic?
+        if not self.conn:
+            raise ValueError("Attempting to get connection before initialisation!")
+        return self.conn
+
+    async def connect(self) -> psq.AsyncConnection:
+        logger.info("Establishing connection to database.", extra={'action': "Data Connect"})
+        self.conn = await psq.AsyncConnection.connect(
+            self._conn_args, autocommit=True, row_factory=row_factory, cursor_factory=self.cursor_factory
+        )
+        for hook in self.conn_hooks:
+            await hook(self.conn)
+        return self.conn
+
+    async def reconnect(self) -> psq.AsyncConnection:
+        return await self.connect()
+
+    def connect_hook(self, coro: Callable[[psq.AsyncConnection], Awaitable[None]]):
+        """
+        Minimal decorator to register a coroutine to run on connect or reconnect.
+
+        Note that these are only run on connect and reconnect.
+        If a hook is registered after connection, it will not be run.
+        """
+        self.conn_hooks.append(coro)
+        return coro
+
+
+@runtime_checkable
+class Connectable(Protocol):
+    def bind(self, connector: Connector):
+        raise NotImplementedError