Support raw http responses on per-request basis

[asvetlov]

There is a part of the conversation on gitter channel:

Is there a way to disable content decoding in aiohttp?
Ah, nevermind, I see the auto_decompress parameter for a ClientSession(). It would be great to be able to do this on a per-request basis. Or the ability to get the raw content from any response.

I think #3440 can solve the issue (along with many others).
Stay tuned.

[aaronst]

A specific example I'm dealing with now is that sometimes the response content does not match the Content-Type header. My current solution is to catch the exception that is raised by Response.read(), create an entirely new ClientSession with auto_decompress=False, and resend the request.

[asvetlov]

Not sure if layered stream readers can help in your specific case.
If stream.read() raises an exception the stream content has undefined state I think.
Data can be partially read and consumed from the underlying .raw stream.
Raw stream cannot keep the whole body, this approach has very high memory footprint.
Instead, the stream has only a part of the unread data buffer.

[gasinvein]

Hello. Is adding this feature still considered?
If not (or not in foreseeable future), can you please point me to the right direction how to implement per-request auto_decompress without altering aiohttp code? Currently I've came up with creating a new ClientSession instance, sharing with the "parent" session the connector, cookie_jar, etc. whenever I need auto_decompress mode flipped; is this valid approach?

[asvetlov]

I can propose adding auto_decompress argument to ClientSession.request() method.

The change is relatively simple, a champion is wanted.

[Daste745]

I'll work on implementing this.