third_party/rust/uniffi_bindgen/src/bindings/python/templates/Async.py

   1 # RustFuturePoll values
   2 _UNIFFI_RUST_FUTURE_POLL_READY = 0
   3 _UNIFFI_RUST_FUTURE_POLL_MAYBE_READY = 1
   4
   5 # Stores futures for _uniffi_continuation_callback
   6 _UniffiContinuationPointerManager = _UniffiPointerManager()
   7
   8 # Continuation callback for async functions
   9 # lift the return value or error and resolve the future, causing the async function to resume.
  10 @_UNIFFI_FUTURE_CONTINUATION_T
  11 def _uniffi_continuation_callback(future_ptr, poll_code):
  12     (eventloop, future) = _UniffiContinuationPointerManager.release_pointer(future_ptr)
  13     eventloop.call_soon_threadsafe(_uniffi_set_future_result, future, poll_code)
  14
  15 def _uniffi_set_future_result(future, poll_code):
  16     if not future.cancelled():
  17         future.set_result(poll_code)
  18
  19 async def _uniffi_rust_call_async(rust_future, ffi_poll, ffi_complete, ffi_free, lift_func, error_ffi_converter):
  20     try:
  21         eventloop = asyncio.get_running_loop()
  22
  23         # Loop and poll until we see a _UNIFFI_RUST_FUTURE_POLL_READY value
  24         while True:
  25             future = eventloop.create_future()
  26             ffi_poll(
  27                 rust_future,
  28                 _UniffiContinuationPointerManager.new_pointer((eventloop, future)),
  29             )
  30             poll_code = await future
  31             if poll_code == _UNIFFI_RUST_FUTURE_POLL_READY:
  32                 break
  33
  34         return lift_func(
  35             _rust_call_with_error(error_ffi_converter, ffi_complete, rust_future)
  36         )
  37     finally:
  38         ffi_free(rust_future)
  39
  40 _UniffiLib.{{ ci.ffi_rust_future_continuation_callback_set().name() }}(_uniffi_continuation_callback)