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Merging upstream version 1.2.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
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Daniel Baumann 2025-02-24 04:05:33 +01:00
parent 844a3e48f2
commit 73f1304e10
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
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README
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Description
Plzip is a massively parallel (multi-threaded), lossless data compressor
Plzip is a massively parallel (multi-threaded) lossless data compressor
based on the lzlib compression library, with a user interface similar to
the one of lzip, bzip2 or gzip.
Plzip can compress/decompress large files on multiprocessor machines
much faster than lzip, at the cost of a slightly reduced compression
ratio. Note that the number of usable threads is limited by file size,
so on files larger than a few GB plzip can use hundreds of processors,
but on files of only a few MB plzip is no faster than lzip.
ratio. Note that the number of usable threads is limited by file size;
on files larger than a few GB plzip can use hundreds of processors, but
on files of only a few MB plzip is no faster than lzip.
When compressing, plzip divides the input file into chunks and
compresses as many chunks simultaneously as worker threads are chosen,
creating a multi-member compressed file.
When decompressing, plzip decompresses as many members simultaneously as
worker threads are chosen. Files that were compressed with lzip will not
be decompressed faster than using lzip (unless the "-b" option was used)
because lzip usually produces single-member files, which can't be
decompressed in parallel.
Plzip uses the lzip file format; the files produced by plzip are fully
compatible with lzip-1.4 or newer, and can be rescued with lziprecover.
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* Additionally lzip is copylefted, which guarantees that it will
remain free forever.
A nice feature of the lzip format is that a corrupt byte is easier to
repair the nearer it is from the beginning of the file. Therefore, with
the help of lziprecover, losing an entire archive just because of a
corrupt byte near the beginning is a thing of the past.
Plzip uses the same well-defined exit status values used by lzip and
bzip2, which makes it safer than compressors returning ambiguous warning
values (like gzip) when it is used as a back end for tar or zutils.
values (like gzip) when it is used as a back end for other programs like
tar or zutils.
Plzip will automatically use the smallest possible dictionary size for
each file without exceeding the given limit. Keep in mind that the
@ -70,7 +86,7 @@ corresponding uncompressed files. Integrity testing of concatenated
compressed files is also supported.
Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Antonio Diaz Diaz.
Copyright (C) 2009-2014 Antonio Diaz Diaz.
This file is free documentation: you have unlimited permission to copy,
distribute and modify it.