[boost] Re: Compression usinig IOStreams library

From: George M. Garner Jr. (gmgarner_at_[hidden])
Date: 2004-09-11 15:44:17

Johnathan,

> Dumb question - is Winzip supposed to be able to read the zlib format? I 
> usually
> use it to decompress .zip or tar.gz archives. <

Well I made that assumption because Winzip and XP both maintain associations 
for the .z extension.  This is from the Winzip help file:

> Since almost all new archives are created in Zip format, WinZip does not 
> provide
> facilities to add to or create files in these formats (however, all other 
> WinZip
> functions are supported). <

 In the code that I included in my previous post I see that I am using a zip 
extension.  But I tried it both ways to no avail.

> I hate these stupid lowercase macros!<

Yes.  It is very bad coding style.  I grepped for in in your library, boost 
and bzip and couldn't find who was defining it.  :-(

>> bool eof = (state_ & f_eof) != 0;
>> if (buf_.ptr() != buf_.end() || eof) {
>> bool done =
>> !filter_->filter(
>> const_cast<const char_type*&>(buf_.ptr()),
>> buf_.end(), next_s, end_s, eof
>> --) && eof;
>> ++) || eof;
>
> Thanks. It took me a long time to get this to work with my sample data, 
> but
> since I tried only a few samples, I guess I'm not surprised it's still 
> wrong.
> Somehow, though, I seem to remember "|| eof" failing, too.
>

You're welcome to the sample project if you like.  The problem is that, with 
the bzip2 sample, eof is reached and next_s != end_s.  That may be a bug in 
itself however I don't think that you can rely on this condition always 
being true at eof.  You also would enter the infinite loop by trying to read 
a malformed zlib or gzip archive, for example.  When eof is reached you have 
to be "done."

> BTW, I just now realized that you're the one I was discussing these issues 
> with
> over at microsoft.public.vc.stl ;-)

Busted.

Regards,

George.