Your compressed response should have HTTP headers Content-Type: text/xml Content-Encoding: gzip
Scott Nichol Do not send e-mail directly to this e-mail address, because it is filtered to accept only mail from specific mail lists. ----- Original Message ----- From: "Nige White" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, November 15, 2004 1:22 PM Subject: Re: Compressing SOAP requests > Scott Nichol wrote: > > >FYI, deflate follows Zlib as described in RFC 1950 > >(http://www.ietf.org/rfc/rfc1950.txt?number=1950). The Zlib DEFLATE method > >of compression is described in RFC 1951, while gzip is described in RFC 1952 > >(http://www.ietf.org/rfc/rfc1952.txt?number=1952). RFC 1952 looks like it > >specifies 10 bytes for the header, so I am not sure why 8 bytes works.... > > > > > > > Well, I've been battling with it. > > Why 8 bytes works... > > zlib already has a 2 byte flag prefix which the gzip compressed data > (after its 10 byte header) does not use, so it *looks* like it works > appending the 8 bytes. > > Here's what I do: > > When recieving gzip data: > > Remove the first 10 bytes, they are the gzip-specific 10 byte header > Remove the last 8 bytes, they consist of a CRC-32 checksum of the > original data, and original data length > Prepend the zlib 2 byte flag: 0x78 0x9c > Call zlib-inflate, and ignore error -5. THis is probably because the > buffer ends abruptly with no Adler checksum > > When sending data as gzip: > > Call zlib-deflate > Remove the 2 zlib flag prefix bytes. > Prepend the 10 byte gzip-specific header > Append a CRC-32 checksum of the original data (Calculated in "DBL" which > has no unsigned arithmetic, and no bit-shift operators!) > Append the original data length > > This works in that I can compress data, and output it to a file which > gunzip will happily inflate to the original data. > > I can also see (in my logfile) the correctly inflated SOAP packets > coming in to my DBL server. > > There does seem to be a problem when SOAP receives by compressed packet. > It is throwing "Content is not allowed in prolog." > > I still set the Content-Type header to "text/html". Should I change this > to indicate to SOAP that it is gzip data coming back? > > I'll be back tomorrow, home time now. > > Cheers, > > Nigel > > _____________________________________________________________________ > This message has been checked for all known viruses. Virus scanning > powered by Messagelabs http://www.messagelabs.com For more information > e-mail : [EMAIL PROTECTED] > > >
