Properly implement AsgiRequest._stream

[dav20011]

Django requests only contain a stream for the request body and lazy load the request.body property if needed. This is very intuitive because you can handle tasks like a file upload without loading the entire file into the memory while keeping the possibility of easily accessing the request body.

AsgiRequests on the other hand load the entire body before the execution of the view and only offer a fake stream. Looking at this code, it seems perfectly doable to handle this exactly like Django does by default. There actually is a TODO for this feature in the code, but I think it was forgotten.

channels/channels/http.py

Lines 119 to 123 in 9c59938

	# TODO: chunked bodies
	self._body = body
	assert isinstance(self._body, bytes), "Body is not bytes"
	# Add a stream-a-like for the body
	self._stream = BytesIO(self._body)

[andrewgodwin]

It was not forgotten, just not implemented yet, since it's a bit trickier to stream this successfully. It should, however, be implemented as you suggest, so I'll leave this open as an enhancement (as it would improve memory efficiency).

[blueyed]

Duplicate of #1001 ?

[carltongibson]

Closing as-per #1001: this'll be part of Django now.