W3C home > Mailing lists > Public > www-lib@w3.org > October to December 1998

Chunked transfer coding

From: <Jim_Ravan@avid.com>
Date: Fri, 18 Dec 1998 10:51:01 -0500
To: www-lib@w3.org
Message-ID: <852566DE.005711E4.00@amm02.avid.com>



>>// Perform a ranged PUT on that anchor.
>>request = HTRequest_new();
>>//HTRequest_addRange(request, "bytes", (char*)&range);
>>//HTRequest_addRqHd(request, HT_C_RANGE);

>>Putting ranges on anything but HEAD and GET requests is tricky (can't be
>>done reliably) as HTTP servers may ignore the ranges. In any case, it has
>>to be content-range and not range as the latter talks about the requested
>>amount of data in the response and not in the entity that you are saving.

>Aha! Then would the safer thing be to start a chunked transfer? Then each
call to my write >routine would write another chunk to the HTTP server. Is
that possible to do? If so, how >can I do it? I am assured that my caller
will eventually tell me to stop writing and I can >then send the "0" and
end the chunked transfer.

As you all can see from the above, we have been talking about chunked
transfer coding. Has anyone successfully sent and received chunked
transfers using libwww? Can anyone tell me how to do it? I've looked at the
code for hours now, and I'm stuck. The mechanism for getting the transfer
encoding and decoding to happen is just a little too opaque for me to
figure out.

The basic idea on my output side - my layer has both output and input, but
the current issue only concerns output - is to have my callers ask me to
start a transfer with the first piece of data they hand me. I would issue
some yet-to-be-determined set of libwww calls and send the first chunk of
the chunked transfer. I would then return to my callers. They would then
pass me <n> additional pieces of data over time which I would continue to
send as chunks in the current chunked entity. Then they would tell me that
they were finished sending the current entity, and I would send a final "0"
chunk to signal the end of the chunked transfer. This seems to me to be
pretty much how HTTP/1.1 envisioned chunked transfer encoding should
happen, but for the life of me, I can't figure out how to get libww to do
it.

Any help?

regards,
-jim
Received on Friday, 18 December 1998 11:45:50 EST

This archive was generated by hypermail pre-2.1.9 : Wednesday, 3 September 2003 17:59:26 EDT