QPACK - proposal to optimize compression

[Brian Swander <[e-mail]>]

Please correct me if I'm wrong here.

It looks like the latest QPACK draft has been optimized to allow encode of both control and data streams in a single pass.
Because of this, we now must support that post-base encoding, and the multiple encoding formats that use Post-Base.
I.e. Literal Header Field with Name Reference and Literal Header Filter With Post-Base Name Reference, and similarly for Indexed Header Field.

To me, it seems like the simpler, more efficient option of removing post-base entirely could be better.   At the cost of requiring 2-pass encode, we can save a few bits for most headers since we would never need the post base header prefix.

So it's a question of looping thru the headers twice, vs. being less efficient on the wire.

I haven't profiled it, but I'd guess that double pass thru the headers isn't going to be that much slower than single pass.   Many of the headers are going to be encoded in both streams.   So the more efficient wire format may be more optimal.

bs