Re: WiSH: A General Purpose Message Framing over Byte-Stream Oriented Wire Protocols (HTTP)

[Takeshi Yoshino <[e-mail]>]

On Sat, Oct 29, 2016 at 1:25 AM, Costin Manolache <[e-mail]> wrote:

> I think WiSH could be great as a fallback to the webpush protocol push
> promises, in devices
> that don't fully support http/2, and for webpush delivery receipts.
>

Great to hear that.


>
> In the context of IoT: since continuation is available, any reason to
> support 64-bit-length frames ?
> Even 32 bit ( 4G ) frames may be unpractical.  I don't know how common
> this int encoding scheme
> is - but using varint or fixed may be easier to handle.
>

It's basically not to introduce any gap with WebSocket's representation
power for compatibility while also keeping it efficient for small frames.

Re: varint,
Actually, old WebSocket protocol I-Ds used base 128 varint for encoding
frame length for binary frames.
https://tools.ietf.org/html/draft-ietf-hybi-thewebsocketprotocol-00
We can choose this as this is efficient for small messages but considered
that WebSocket encoding is already common and honored input which led to
the WebSocket encoding. IIRC there was some feedback from hardware
developer against to 128 varint, but I cannot find it now.

Re: big frames,
We're also seeing that very long messages are uncommon from Chromium's UMA
stats. We might be able to share that.

Re: small over head for small frames,
For the use cases where WiSH is layered on top of HTTP2 overhead and TLS
record overhead, this difference might be negligible.

So, ... I'm open to changing the encoding, but want to hear more :)