Re: [hybi] Framing take IV [why fragment]

[John Tamplin <[e-mail]>]

On Thu, Aug 5, 2010 at 12:47 PM, Roberto Peon <[e-mail]> wrote:

> The biggest reason that variable length encoding is annoying is that it
> either adds complexity of buffer management or it adds overhead dealing with
> the system.
>
> A big advantage of length-prefixed data is that one need only read the
> length, and then one can do a single alloc and read() to consume the rest of
> the message exactly.
>
> If any part of this is sentinel based (and that is what BER is,
> effectively), you end up either doing read() one byte at a time, or you end
> up doing a read for something you're guessing is larger than the max length.
> If you guess wrong, you either have to have kept the encoded state from the
> previous read, read more (involves another alloc), and only then do you get
> to alloc and read the payload.
>
> If you've guessed wrong and you read too much, then you have to save that
> data, alloc another buffer, move it, and only then can you safely delete the
> previous buffer.
>
> This is a fair bit of complexity.
> What is the gain?
>

I agree completely with this argument.

Since there was a post made by the chair saying that a fixed-length length
field and fragment support had strong support and would be declared the
consensus unless technical arguments for the variable-length length fields
are presented, it seems like those who don't like the fixed length field
need to present a case.

-- 
John A. Tamplin
Software Engineer (GWT), Google