Calculating a hash for UploadFile

[zevisert]

In a project I'm working on, I'd like to have a simple hash of the bytes received for a multipart/form-data UploadFile, my first instinct knowing that this wasn't something that is directly available from starlette was to subclass the UploadFile class myself to update the hash on seek and write calls, but I don't think that will work since we wan't provide our customized UploadFile subclass back to the starlette.formparsesrs.MultiPartParser.

I can always just read through the file in my route hander myself to calculate the hash, but since the underlaying file is a spooled tempfile, doing to will create a whole extra load of the file from disk if it's been rolled already. Better ideas would be appreciated!

[adriangb]

This seems like a reasonable feature request to me. We do want to support it. I think maybe #1382 is the first step. Maybe bump that issue?

[zevisert]

Thanks, so I am correct in that for now I have to take a second pass over an UploadFile's contents to compute an (eg MD5) hash?

[adriangb]

Yes, currently that's what you would need to do.