[dcc2] Multi headers + metadata

[Dan Smith]

Hi everyone,

It appears that we have come to a consensus regarding XML.  It would 
require many authors to add additional dependances to their projects, and 
may hinder adaptation.  MIME/HTTP style headers are simple to parse and can 
mimic the same data structures that xml can (with clever work).  If they 
are good enough for http and SIP, I am sure we will not have a problem with 
them.  What do you think about this type of representation for our header 
metadata?

Speaking of metadata, what additional information should we 
standardize?  Under the current transfer proposal, we need a unique id for 
each file listed in a header, file name+path, and size.  Any additional 
information such as md5 hash, description, your ideas, etc.. can be 
optionally included.  Any ideas as to what other metadata would be useful 
to client authors?

What about the transport?  Right now the idea is to create one connection 
and send the header information, then request the files one at a time over 
this connection.  They will be sent in the order that they are 
requested.  This seems clean and simple.  Are we in agreement on this or 
are there other ideas out there?

Regarding compression:  IRC file transfers have traditionally required the 
size of the file to be known before the transfer, and the entire contents 
to be written to the connection.  This is why sending multiple files is 
needed, to eliminate the need to create a compressed archive on disk or in 
memory (to know the size) before sending a group of files, which is not 
feasible for large files.  Adding a streaming compression would make the 
size unknown and we would have to implement some sort of chunking 
mechanism, at which point it would be easier to abandon IRC transfers and 
use some other well know protocol (http for instance).  Is there really a 
need for this?  Perhaps it would work for smaller files (such as our 
headers) and we could make it an option?

Lots of questions, hope is spurs some discussion!

Cheers!
Dan

---------------------------
Dan Smith
+1 608-213-2867
Algenta Technologies, LLC