Implemented alembic migrations, added cursors closing task.

app/cursors.py

@@ -0,0 +1,78 @@
+from fastapi.routing import APIRouter
+from data.schemas import (
+    CachedCursorOut,
+)
+from fastapi import Depends, status
+from data.crud import (
+    read_connection,
+    read_select_query,
+)
+from core.dependencies import get_db, get_current_user, get_admin_user
+from core.exceptions import (
+    QueryNotFound,
+    ConnectionNotFound,
+    CursorNotFound,
+)
+from dbs import mysql
+
+router = APIRouter()
+
+
+@router.post("/", dependencies=[Depends(get_current_user)])
+async def create_cursor_endpoint(
+    query_id: int,
+    connection_id: int,
+    db=Depends(get_db),
+) -> CachedCursorOut:
+    query = await read_select_query(db=db, query_id=query_id)
+
+    if query is None:
+        raise QueryNotFound
+    connection = await read_connection(db=db, connection_id=connection_id)
+
+    if connection is None:
+        raise ConnectionNotFound
+
+    cached_cursor = await mysql.create_cursor(query=query, connection_id=connection_id)
+
+    mysql.cached_cursors[cached_cursor.id] = cached_cursor
+    print(mysql.cached_cursors)
+    return cached_cursor
+
+
+@router.get("/", dependencies=[Depends(get_current_user)])
+async def get_all_cursors() -> list[CachedCursorOut]:
+    return mysql.cached_cursors.values()
+
+
+@router.get("/{cursor_id}", dependencies=[Depends(get_current_user)])
+async def get_cursors(cursor_id: str) -> CachedCursorOut:
+    try:
+        return mysql.cached_cursors[cursor_id]
+    except KeyError:
+        raise CursorNotFound
+
+
+@router.delete(
+    "/",
+    dependencies=[Depends(get_admin_user)],
+    status_code=status.HTTP_204_NO_CONTENT,
+)
+async def close_all_cursor() -> None:
+    for cached_cursor in mysql.cached_cursors.values():
+        await cached_cursor.close()
+    mysql.cached_cursors.clear()
+
+
+@router.delete(
+    "/{cursor_id}",
+    dependencies=[Depends(get_current_user)],
+    status_code=status.HTTP_204_NO_CONTENT,
+)
+async def close_cursor(cursor_id: str) -> None:
+    cached_cursor = mysql.cached_cursors.get(cursor_id, None)
+    if cached_cursor is None:
+        raise CursorNotFound
+
+    await cached_cursor.close()
+    del mysql.cached_cursors[cursor_id]