Is async file reading supported?

[NicolasHug]

The docs of PathManager.opena() suggest that async reading is supported:

iopath/iopath/common/file_io.py

Lines 1101 to 1103 in 9dd723a

	Usage (read):
	async def my_function():
	return await path_manager.opena(uri, "r").read()

But running the suggested code leads to the following error:

iopath/iopath/common/file_io.py

Lines 352 to 355 in 9dd723a

	# Restrict mode until `NonBlockingIO` has async read feature.
	valid_modes = {"w", "a", "b"}
	if not all(m in valid_modes for m in mode):
	raise ValueError(f"`opena` mode must be write or append for path {path}")

Are there plans to support async file reading? Thanks!

[sujitoc]

Async reads are currently not supported for the generic PathHandler. However, one path handler (for internal Meta use) does support it.

[NicolasHug]

Thanks for your reply @sujitoc . Would you know if there are plans to support async reading for regular on-disk files?

[rjy7wb]

this code already looks a lot like https://github.com/python/cpython/blob/3.11/Lib/asyncio/streams.py

more specifically the StreamReader, and StreamWriter classes