zlib, gzip and HTTP compression.

[jj]

Content-Length must be the length of original, before compression.
So try

print "Content-Length: %d" % os.path.getsize("test.html")

JJ
Alan Kennedy wrote:

> jj <jj at void.si> wrote in message news:<svct3uck4rce72mdl7drndt5v2a3965k45 at 4ax.com>...
> > dont use zlib,
> > http requires data in gzip format, zlip.compress returns quite
> > different structure.
> > so import gzip ...
>
> Thanks JJ.
>
> OK, I understand the problem better now. I read RFC 1952, which
> explains the structure of gzip files. And looking at
> python/Lib/gzip.py, it appears to construct exactly the structure
> required.
>
> So I reworked my code to use gzip, and I'm almost there. The first
> ~200 bytes of the HTML file now appear exactly as they should, but
> then it corrupts after that. Obviously the mechanism for communicating
> from the server to the client that I am sending gzipped data is
> working, but it looks like I'm sending gzipped data that is slightly
> corrupt, or I'm telling the client the wrong length, or some such.
> Close, but no cigar!
>
> There is obviously some small detail that I am missing, such as
> character translation during the print statement(?), one extra byte
> need somewhere, etc?
>
> Any hints anyone?
>
> The new code is presented below.
>
> TIA,
>
> Alan.
>
> ------------------------------------------
> #! C:/python21/python.exe
>
> import string
> import os
> import gzip
> import StringIO
>
> # Use any old HTML file (which displays fine standalone)
>
> f = open("test.html")
> buf = f.read()
> f.close()
>
> def compressBuf(buf):
>         zbuf = StringIO.StringIO()
>         zfile = gzip.GzipFile(None, 'wb', 9, zbuf)
>         zfile.write(buf)
>         zfile.close()
>         return zbuf.getvalue()
>
> acceptsGzip = 0
> if string.find(os.environ["HTTP_ACCEPT_ENCODING"], "gzip") != -1:
>         acceptsGzip = 1
>         zbuf = compressBuf(buf)
>
> print "Content-type: text/html"
> if acceptsGzip:
>         print "Content-Encoding: gzip"
>         print "Content-Length: %d" % (len(zbuf))
>         print                                     # end of headers
>         print zbuf                                # and then the buffer
> else:
>         print                                     # end of headers
>         print buf                                 # and then the buffer
>
> # end of script
> ------------------------------------------------------