• Lester L. Martin II <Lester ewam-associates.com> Sep 30 2007
• Lutger <lutger.blijdestijn gmail.com> Sep 30 2007
• Daniel Keep <daniel.keep.lists gmail.com> Sep 30 2007
• Lutger <lutger.blijdestijn gmail.com> Sep 30 2007
• Jan Claeys <usenet janc.be> Oct 01 2007

Lester L. Martin II <Lester ewam-associates.com> writes:

Dear Mr. Keep,
I believe 7z to be much better than the ones you described as it has better
compression although I haven't look at zip and tar and compression methods that
deeply. I've always judged compression by how small it gets my files.  The way
you judge it seems to be more interesting.
Lester L. Martin II
Daniel Keep Wrote:

 
 
 Lester Martin wrote:
 Lester Martin Wrote:
 Dear Mr. Miller,
 I have gotten DFL to finally work with tango. After I have everything working
in C# i'll rewrite it with tango and dfl.
 
 Does anyone know of a good zip compression library for D or is this integrated
into tango in an easy to use way like example below.
 FastZip fz = new FastZip(file);
 fz.unzipTo(ftuzt);
 fz.setNewZip(file2);
 fz.compressDirToCurZip(dir);
 
 Those method names may very as long as such functionality is provided.
 


 I've got the beginnings of a Zip archive implementation for Tango lying
 around, but it's been held up by various things.  There's little doubt
 that Tango will have Zip support fairly soon (and by "fairly soon" I
 mean by around the end of the year.)
 
 <rant>
 
 Incidentally, Zip is a complete bastard of a format to support.  The
 format document is horribly written, disjointed, confusing, incomplete
 and the format itself hasn't so much evolved as *congealed* over time.
 
 For instance: there's something like four different places the list of
 files in an archive can appear, and just to make things fun, the format
 spec doesn't say *anything* about which one to trust.
 
 Of course, tar isn't much better; that one has *multiple* incompatible
 standards; half of the time, there's no reliable way to tell them apart,
 either.
 
 I haven't had the heart to even try looking at 7z yet...
 
 </rant>
 
 	-- Daniel

Lutger <lutger.blijdestijn gmail.com> writes:

Lester L. Martin II wrote:
 Dear Mr. Keep,
 I believe 7z to be much better than the ones you described as it has better
compression although I haven't look at zip and tar and compression methods that
deeply. I've always judged compression by how small it gets my files.  The way
you judge it seems to be more interesting.
 Lester L. Martin II
 Daniel Keep Wrote:
 


While 7z is a great compression format, (de)compressing is much slower 
than the zlib codec. Furthermore, 7z is LGPL and zlib has a BSD style 
license. tar doesn't do compression by itself, it's for archiving only.

Daniel Keep <daniel.keep.lists gmail.com> writes:

Lutger wrote:
 Lester L. Martin II wrote:
 Dear Mr. Keep,
 I believe 7z to be much better than the ones you described as it has
 better compression although I haven't look at zip and tar and
 compression methods that deeply. I've always judged compression by how
 small it gets my files.  The way you judge it seems to be more
 interesting.
 Lester L. Martin II
 Daniel Keep Wrote:


 While 7z is a great compression format, (de)compressing is much slower
 than the zlib codec. Furthermore, 7z is LGPL and zlib has a BSD style
 license. tar doesn't do compression by itself, it's for archiving only.


Well, I *did* say "Zip", "tar" and "7z" as opposed to "DEFLATE/zlib",
"bzip2" and "LZMA".  I've noticed lots of people tend to confuse archive
and compression formats.  :3

Incidentally, Tango now supports zlib (used by Zip and gzip) and bzip2
(used by, surprise, surprise, bzip2) as compression filters.

<rant id="second">

Now, I am aware that LZMA appears to be a generally better compression
algorithm, but the reason I haven't tried adding support for it yet is
because there doesn't appear to be a single "liblzma" available.
There's the official SDK which is written in C++ with lots of
Windows-specific code (which obviously makes it difficult to use), and
then there's a portable, independent implementation.

But, joy of joys, they're not compatible with each other.  *sigh*

As for 7z itself, from what I can tell, the archives themselves are some
kind of object-tree.  Frankly, that scares the hell out of me.  :|

Honestly, I've been tempted on more than one occasion to just write a
*simple* archive format for Tango.  Of course, no one else would support
it, which would kinda defeat the purpose...

Ok, bed time.

</rant>

	-- Daniel

Lutger <lutger.blijdestijn gmail.com> writes:

Daniel Keep wrote:
 
 Lutger wrote:
 Lester L. Martin II wrote:
 Dear Mr. Keep,
 I believe 7z to be much better than the ones you described as it has
 better compression although I haven't look at zip and tar and
 compression methods that deeply. I've always judged compression by how
 small it gets my files.  The way you judge it seems to be more
 interesting.
 Lester L. Martin II
 Daniel Keep Wrote:


 than the zlib codec. Furthermore, 7z is LGPL and zlib has a BSD style
 license. tar doesn't do compression by itself, it's for archiving only.


 Well, I *did* say "Zip", "tar" and "7z" as opposed to "DEFLATE/zlib",
 "bzip2" and "LZMA".  I've noticed lots of people tend to confuse archive
 and compression formats.  :3


I know, I meant to say that, talking about compression only, speed can 
be a criterium too.

...
 Honestly, I've been tempted on more than one occasion to just write a
 *simple* archive format for Tango.  Of course, no one else would support
 it, which would kinda defeat the purpose...


I'm not sure. It might still be useful if it would offer advantages 
above zip / tar / whatever.

Jan Claeys <usenet janc.be> writes:

Op Mon, 01 Oct 2007 02:53:08 +1000
schreef Daniel Keep <daniel.keep.lists gmail.com>:

 Incidentally, Tango now supports zlib (used by Zip and gzip) and bzip2
 (used by, surprise, surprise, bzip2) as compression filters.


Actually, also both the .zip & .7z "containers" support bzip2
compression in their recent versions.   :)

 Now, I am aware that LZMA appears to be a generally better compression
 algorithm, but the reason I haven't tried adding support for it yet is
 because there doesn't appear to be a single "liblzma" available.
 There's the official SDK which is written in C++ with lots of
 Windows-specific code (which obviously makes it difficult to use), and
 then there's a portable, independent implementation.
 
 But, joy of joys, they're not compatible with each other.  *sigh*


There's also p7zip, which seems to work?


-- 
JanC