estimated Content-Length with chunked encoding

*I sent this once before, but I think to the wrong address, excuse me if
it's a duplicate*

 

I am new to this mailing list.  I wanted to bounce an idea that I've had for
a while off everyone/anyone.  Basically I'd like to provide the sender of a
chunked encoding message to indicate an estimate of the content.  In the
following example resource.zip is created dynamically, however the
approximate size is known.

 

C: Get /resource.zip HTTP/1.1

 

S: HTTP/1.1 200 OK

S: Transfer-Encoding: chunked

S: Estimated-Content-Length: 300000

 

This would allow for the recipient of such a message to prepare for a
message of a certain size.  The best example of this at work would be when a
browser displays the estimated time remaining.  Today browsers indicate "Not
Known", or show nothing.  This could also be useful for PUT requests, where
it would allow the recipient to make a decision based on what the sender
expects the size to be (possibly allocating resources, or rejecting the
request altogether).

 

If something like this already exists in 1.1 or is already being considered,
please accept my apologies in advance.  Otherwise does, anyone have any
feedback?