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Adding upstream version 1.0~rc1.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
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Daniel Baumann 2025-02-24 03:54:35 +01:00
parent a92d8a2cdd
commit d49eb8d954
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
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doc/plzip.texinfo
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@ -6,8 +6,8 @@
@finalout
@c %**end of header
@set UPDATED 1 March 2012
@set VERSION 0.9
@set UPDATED 8 March 2013
@set VERSION 1.0-rc1
@dircategory Data Compression
@direntry
@ -35,16 +35,16 @@
This manual is for Plzip (version @value{VERSION}, @value{UPDATED}).
@menu
* Introduction:: Purpose and features of plzip
* Invoking Plzip:: Command line interface
* Program Design:: Internal structure of plzip
* File Format:: Detailed format of the compressed file
* Problems:: Reporting bugs
* Concept Index:: Index of concepts
* Introduction:: Purpose and features of plzip
* Program Design:: Internal structure of plzip
* Invoking Plzip:: Command line interface
* File Format:: Detailed format of the compressed file
* Problems:: Reporting bugs
* Concept Index:: Index of concepts
@end menu
@sp 1
Copyright @copyright{} 2009, 2010, 2011, 2012 Antonio Diaz Diaz.
Copyright @copyright{} 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz.
This manual is free documentation: you have unlimited permission
to copy, distribute and modify it.
@ -115,6 +115,28 @@ invalid input file, 3 for an internal consistency error (eg, bug) which
caused plzip to panic.
@node Program Design
@chapter Program Design
@cindex program design
For each input file, a splitter thread and several worker threads are
created, acting the main thread as muxer (multiplexer) thread. A "packet
courier" takes care of data transfers among threads and limits the
maximum number of data blocks (packets) being processed simultaneously.
The splitter reads data blocks from the input file, and distributes them
to the workers. The workers (de)compress the blocks received from the
splitter. The muxer collects processed packets from the workers, and
writes them to the output file.
When decompressing from a regular file, the splitter is removed and the
workers read directly from the input file. If the output file is also a
regular file, the muxer is also removed, and the workers write directly
to the output file. With these optimizations, decompression speed of
large files with many members is only limited by the number of
processors available and by I/O speed.
@node Invoking Plzip
@chapter Invoking Plzip
@cindex invoking
@ -180,7 +202,7 @@ usually give better compression ratios but longer compression times.
Set the number of worker threads. Valid values range from 1 to "as many
as your system can support". If this option is not used, plzip tries to
detect the number of processors in the system and use it as default
value.
value. @w{@samp{plzip --help}} shows the system's default value.
@item -o @var{file}
@itemx --output=@var{file}
@ -268,25 +290,15 @@ Table of SI and binary prefixes (unit multipliers):
@end multitable
@node Program Design
@chapter Program Design
@cindex program design
For each input file, a splitter thread and several worker threads are
created, acting the main thread as muxer (multiplexer) thread. A "packet
courier" takes care of data transfers among threads and limits the
maximum number of data blocks (packets) being processed simultaneously.
The splitter reads data blocks from the input file, and distributes them
to the workers. The workers (de)compress the blocks received from the
splitter. The muxer collects processed packets from the workers, and
writes them to the output file.
@node File Format
@chapter File Format
@cindex file format
Perfection is reached, not when there is no longer anything to add, but
when there is no longer anything to take away.@*
--- Antoine de Saint-Exupery
@sp 1
In the diagram below, a box like this:
@verbatim
+---+
@ -322,15 +334,17 @@ All multibyte values are stored in little endian order.
A four byte string, identifying the lzip format, with the value "LZIP".
@item VN (version number, 1 byte)
Just in case something needs to be modified in the future. Valid values
are 0 and 1. Version 0 files are deprecated. They can contain only one
member and lack the @samp{Member size} field.
Just in case something needs to be modified in the future. 1 for now.
@item DS (coded dictionary size, 1 byte)
Bits 4-0 contain the base 2 logarithm of the base dictionary size.@*
Bits 7-5 contain the number of "wedges" to substract from the base
dictionary size to obtain the dictionary size. The size of a wedge is
(base dictionary size / 16).@*
Lzip divides the distance between any two powers of 2 into 8 equally
spaced intervals, named "wedges". The dictionary size is calculated by
taking a power of 2 (the base size) and substracting from it a number of
wedges between 0 and 7. The size of a wedge is (base_size / 16).@*
Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@*
Bits 7-5 contain the number of wedges (0 to 7) to substract from the
base size to obtain the dictionary size.@*
Example: 0xD3 = (2^19 - 6 * 2^15) = (512KiB - 6 * 32KiB) = 320KiB@*
Valid values for dictionary size range from 4KiB to 512MiB.
@item Lzma stream
@ -344,8 +358,9 @@ CRC of the uncompressed original data.
Size of the uncompressed original data.
@item Member size (8 bytes)
Total size of the member, including header and trailer. This facilitates
safe recovery of undamaged members from multi-member files.
Total size of the member, including header and trailer. This field acts
as a distributed index, and facilitates safe recovery of undamaged
members from multi-member files.
@end table