[Bug-tar] added support for lz4 and zstd

[Sven C. Dack]

Hello,

I've created a patch for tar, which adds support for lz4 and zstd 
compression. Both compression tools have become increasingly popular and 
offer high-speed compression and decompression, making them interesting 
alternatives to previous compression tools.

lz4 is similar to lzo, but offers faster decompression. zstd is similar 
to gzip, but offers much faster compression and decompression.

See also:

    http://lz4.github.io/lz4/

    http://facebook.github.io/zstd/

For example, creating an archive from a directory of 1.12 GB containing 
binary and ASCII files ("/usr/local/gnu/"):

Compression

name         time     size       ratio
gnu.tar.gz     57.2s  534077354  44.3%
gnu.tar.bz2  1:53.9s  509401491  42.3%
gnu.tar.xz   7:15.6s  423886520  35.2%
gnu.tar.lz   7:37.2s  425162846  35.3%
gnu.tar.lzo     4.7s  676569472  56.2%
gnu.tar.lz4     4.9s  676600069  56.2%
gnu.tar.zst    10.7s  517897416  43.0%

Decompression

name         time
gnu.tar.gz    7.1s
gnu.tar.bz2  45.2s
gnu.tar.xz   26.3s
gnu.tar.lz   30.4s
gnu.tar.lzo   3.5s
gnu.tar.lz4   2.0s
gnu.tar.zst   3.2s

A second example using the Linux kernel source code (4.12.4), containing 
697 MB of data:

Compression

name           time     size       ratio
linux.tar.gz     28.2s  156988489  21.4%
linux.tar.bz2  1:05.5s  120659282  16.5%
linux.tar.xz   4:26.9s  102214892  13.9%
linux.tar.lz   4:18.4s  104105244  14.2%
linux.tar.lzo     3.6s  261745137  35.7%
linux.tar.lz4     3.9s  252707015  34.5%
linux.tar.zst     5.9s  150448272  20.5%

Decompression

name           time
linux.tar.gz    3.6s
linux.tar.bz2  19.4s
linux.tar.xz    7.2s
linux.tar.lz    8.1s
linux.tar.lzo   2.5s
linux.tar.lz4   1.5s
linux.tar.zst   2.1s

(The tools were used with their default arguments. The hardware used was 
an AMD FX8350 4GHz.)

Attached files are:

patch-part-1 - diffs of buffer.c config.h.in configure.ac suffix.c tar.c
patch-part-2 - diffs of tar.texi tar.1 cs.po de.po fi.po ga.po id.po 
ru.po sl.po zh_CN.po

Cheers

patch-part-1
Description: Text document

patch-part-2
Description: Text document