[Caml-list] bindings for xz compression and decompression ?

[Caml-list] bindings for xz compression and decompression ?

[Ralf Treinen]

Hi,

are there any bindings for xz compression and decompression? camlzip doesn't
seem to include these, according to [1]. Debian is in the process of moving
its repository indexes to xz compression, so we (dose) will in the near future
need at least a way to read these compressed files.

Could this be added to camlzip?

-Ralf.

[1] https://forge.ocamlcore.org/projects/camlzip/

Re: [Caml-list] bindings for xz compression and decompression ?

[Bergman Andrey]

> Could this be added to camlzip?

Probably not, because there is a separate bzip2 binding, which is not merged into camlzip.

Combined binding library for different archive would infect system with multiple dependencies. Moreover, some archive types, like xz or rar are OS specific (they nearly are not present in other OSes).

> are there any bindings for xz compression and decompression?

There is an outdated binding for lzma. I can update it, if you really need that.

08.09.2016, 10:05, "Ralf Treinen" <treinen@free.fr>:
> Hi,
>
> are there any bindings for xz compression and decompression? camlzip doesn't
> seem to include these, according to [1]. Debian is in the process of moving
> its repository indexes to xz compression, so we (dose) will in the near future
> need at least a way to read these compressed files.
>
> Could this be added to camlzip?
>
> -Ralf.
>
> [1] https://forge.ocamlcore.org/projects/camlzip/
>
> --
> Caml-list mailing list. Subscription management and archives:
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Re: [Caml-list] bindings for xz compression and decompression ?

[Eric Cooper]

In approx, I just use a Sys.command call to decompress to a temporary
file and then open that.  It has these benefits:
  * for gzip at least, it's faster than camlzip
  * easily detects corrupted files (reading the output stream of a
    decompressor doesn't do that until it's too late)
  * easy to change compression schemes or support multiple ones based
    on file extension, say

--
Eric Cooper             e c c @ c m u . e d u

Re: [Caml-list] bindings for xz compression and decompression ?

[Ben Millwood]

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async_extended has Async_extended.Std.Reader.with_xzip_file

https://ocaml.janestreet.com/ocaml-core/latest/doc/async_extended/Std/Reader.mod/#/with_xzip_file.val

Internally it just invokes xzcat, which may or may not satisfy your
requirements. There's (as far as I know) no provided way to write xz files.

On 9 September 2016 at 03:45, Eric Cooper <ecc@cmu.edu> wrote:

> In approx, I just use a Sys.command call to decompress to a temporary
> file and then open that.  It has these benefits:
>   * for gzip at least, it's faster than camlzip
>   * easily detects corrupted files (reading the output stream of a
>     decompressor doesn't do that until it's too late)
>   * easy to change compression schemes or support multiple ones based
>     on file extension, say
>
> --
> Eric Cooper             e c c @ c m u . e d u
>
> --
> Caml-list mailing list.  Subscription management and archives:
> https://sympa.inria.fr/sympa/arc/caml-list
> Beginner's list: http://groups.yahoo.com/group/ocaml_beginners
> Bug reports: http://caml.inria.fr/bin/caml-bugs
>

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Re: [Caml-list] bindings for xz compression and decompression ?

[Ralf Treinen]

Hiello again,

thanks to everybody for your replies.

On Fri, Sep 09, 2016 at 07:25:12AM +0800, Ben Millwood wrote:

> Internally it just invokes xzcat, which may or may not satisfy your
> requirements. There's (as far as I know) no provided way to write xz files.

I think I will follow that line (and I only need a reader, not a writer).

Cheers -Ralf.

Re: [Caml-list] bindings for xz compression and decompression ?

[Adrien Nader]

Hi,

ocaml-archive[1] has read-only bindings to libarchive which handles xz
through liblzma. I've used it for quite a bit of time now. I have a few,
non-upstream, small patches to bind a few more functions (on-the-fly
path-rewrite, read from bigarray, extract to disk (?), getters and
setters for libarchive's "pathname",
archive_entry_{set_,}{hard,sym}link() and archive_entry_set_link). If
they're of interest I can take some time to share them properly (they're
already public, just not announced).

[1] https://forge.ocamlcore.org/projects/ocaml-archive/

-- 
Adrien Nadr