[NNTP] Compressed LIST (and other commands) answers

[Julien ÉLIE]

Hi all,

> ZLIST LZMA BASE64 ACTIVE
> ZLIST NONE NONE ACTIVE         -> which would be like LIST ACTIVE
> ZLIST LZMA NONE ACTIVE         -> for binary-clean implementations
> ZLIST BZIP2 YENC ACTIVE comp.*

Is that construction a bad idea?

Is it best to have new commands?

  ZHDR LZMA BASE64 Injection-Info 1-
  ZLIST LZMA BASE64 ACTIVE
  ZOVER LZMA BASE64 1-
  ZTAKETHIS LZMA NONE 123 <valid at mid>

or a generic one (name to be defined) like:

  ZCOMMAND LZMA BASE64 0 HDR Injection-Info 1-
  ZCOMMAND LZMA BASE64 0 LIST ACTIVE
  ZCOMMAND LZMA BASE64 0 OVER 1-
  ZCOMMAND LZMA NONE 123 TAKETHIS <valid at mid>

The advantage of the first form is that it can be defined
for each command (but more exhausting to define).
The generic form would allow anybody to use compressed
commands for anything that supports it.
We could have a new capability entry:
  ZCOMMAND HDR LIST NEWNEWS OVER STREAMING
showing the compressed commands understood (the name of
a capability follows ZCOMMAND in CAPABILITIES).

But how to mention that HEAD can be compressed...  Unless
HEAD and CAPABILITIES are the only commands that cannot
be compressed.  The resulting output is small, though.
So maybe it is OK to do that.


Note that I added a third argument (default to 0 when
unused) because we can send unencoded binaries.  So we need
to know the number of bytes to receive.

  ZCOMMAND LZMA NONE 5 TAKETHIS <valid at mid>
  12345\r\n
  .\r\n



Any comment about that?
Is it a wrong direction I am suggesting here?
How could it be done better?



> The problem is that IANA does not register, as far as I can see,
> compression names or encoding names like these.
> I was imagining something like SASL mechanisms could be useful
> to have here.
> Because if we force lzma+base64, what if new algorithms more
> efficient arrive?  There is lzma2 for instance.  And base64 is
> not the best encoding...

Could we imagine to have a IANA registry for that? (GZIP, LZMA, LZMA2,
YENC, BASE64, etc.)

-- 
Julien ÉLIE

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