Turso - is the SQLite compatible database written in Rust. One of the important features of the Turso - is async IO execution which can be used with modern storage backend like IO uring.

Your task is to generate ASYNC Python driver with the API similar aiosqlite (which is similar to DB-API 2 of sqlite module) by REUSING current sync driver imiplementation.

Rules

General rules for driver implementation you MUST follow and never go against these rules:

• STRUCTURE of the implementation
  • Declaration order of elements and semantic blocks MUST be exsactly the same
  • (details and full enumerations omited in the example for brevity but you must generate full code)

# all imports must be at the beginning - no imports in the middle of function
from typing import ...
from queue import SimpleQueue

from .worker import Worker
from .lib import ( 
    Connection as BlockingConnection,
    Cursor as BlockingCursor,
    ...
)

# Connection goes FIRST
class Connection:
    def __init__(connector: Callable[[], BlockingConnection]): ...
    # internal worker MUST be stopped when connection goes out of context scope
    # close must wait for worker to be stopped
    async def close(...): ...
    # make Connection instance awaitable
    def __await__(...): ...
    async def __aenter__(...): ...
    # just close the connection - do not add any extra logic
    async def __aexit__(...): ...
        await self.close()
    ...

# Cursor goes SECOND
class Cursor: ...

# connect is not async because it returns awaitable Connection
# same signature as in the lib.py
def connect(...): ...

• USE already implemented driver - DO NOT copy it
• USE primitives from the queue module in order to send work to the separate Thread
• USE per-connection thread to execute database work
• FOLLOW the pattern:

# create future for completion
future = asyncio.get_event_loop().create_future()
# put the work to the unbounded queue
queue.put_nowait((future, function))

• NEVER block main event loop (e.g., do not use Queue with block=True - prefer unbounded SimpleQueue instead)
• REUSE data structures from lib.py if possible (e.g. exceptions)
• DO NOT accept extra loop parameter - ALWAYS use asyncio.get_event_loop()
• CREATE separate thread to execute Turso request and proxy all methods to these thread in order to not block event loop with database work
• DO NOT reimplement logic of the execution - reuse methods and classes from lib.py
• AVOID cryptic names - prefer short but concise names (wr is BAD, full_write is GOOD)
• NEVER put import in the middle of a function - always put all necessary immports at the beginning of the file
• FOCUS on code readability: if possible extract helper function but make sure that it will be used more than once and that it really contribute to the code readability
• WATCH OUT for variables scopes and do not use variables which are no longer accessible
• WATCH OUT for operations atomicity: DO NOT split atomic work in units which may be mixed with other work in async context - breaking atomicity guarantees
• USE forward reference string in when return method type depends on its class:

class T: 
    def f(self) -> 'T':

Implementation

• Put compact citations from the official DB-API doc if this is helpful
• Driver must implement context API for Python to be used like with ... as conn: ...

Blocking driver

For turso db execution you MUST reuse blocking implementation:

SQLite-like DB API

Make driver API similar to the SQLite DB-API2 for the python.

Pay additional attention to the following aspects:

• SQLite DB-API2 implementation implicitly opens transaction for DML queries in the execute(...) method:

  If autocommit is LEGACY_TRANSACTION_CONTROL, isolation_level is not None, sql is an INSERT, UPDATE, DELETE, or REPLACE statement, and there is no open transaction, a transaction is implicitly opened before executing sql.

  • MAKE SURE this logic implemented properly
• Implement .rowcount property correctly, be careful with executemany(...) methods as it must return rowcount of all executed statements (not just last statement)
• Convert exceptions from rust layer to appropriate exceptions documented in the sqlite3 db-api2 docs
• BE CAREFUL with implementation of transaction control. Make sure that in LEGACY_TRANSACTION_CONTROL mode implicit transaction will be properly commited in case of cursor close

Also, make types and API compatible with aiosqlite (note, that aiosqlite implements some other methods, which can be omitted now, like interrupt)