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authorDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 09:34:21 +0000
committerDaniel Baumann <mail@daniel-baumann.ch>2015-11-07 09:34:21 +0000
commitb17878626c3ca5b4422e4b1e521b23742a9ae720 (patch)
treeee055f2d100ff11387c19ba8fa57540533995f7e /doc/lzip.texinfo
parentAdding upstream version 1.13. (diff)
downloadlzip-b17878626c3ca5b4422e4b1e521b23742a9ae720.tar.xz
lzip-b17878626c3ca5b4422e4b1e521b23742a9ae720.zip
Adding upstream version 1.14.upstream/1.14
Signed-off-by: Daniel Baumann <mail@daniel-baumann.ch>
Diffstat (limited to '')
-rw-r--r--doc/lzip.texinfo52
1 files changed, 32 insertions, 20 deletions
diff --git a/doc/lzip.texinfo b/doc/lzip.texinfo
index 0ebc9ca..76ccfc9 100644
--- a/doc/lzip.texinfo
+++ b/doc/lzip.texinfo
@@ -6,8 +6,8 @@
@finalout
@c %**end of header
-@set UPDATED 24 February 2012
-@set VERSION 1.13
+@set UPDATED 17 February 2013
+@set VERSION 1.14
@dircategory Data Compression
@direntry
@@ -45,7 +45,8 @@ This manual is for Lzip (version @value{VERSION}, @value{UPDATED}).
@end menu
@sp 1
-Copyright @copyright{} 2008, 2009, 2010, 2011, 2012 Antonio Diaz Diaz.
+Copyright @copyright{} 2008, 2009, 2010, 2011, 2012, 2013
+Antonio Diaz Diaz.
This manual is free documentation: you have unlimited permission
to copy, distribute and modify it.
@@ -87,12 +88,16 @@ split the compressed output in volumes of a given size, even when
reading from standard input. This allows the direct creation of
multivolume compressed tar archives.
-The amount of memory required for compression is about 5 MiB plus 1 or 2
-times the dictionary size limit (1 if input file size is less than
-dictionary size limit, else 2) plus 8 times the dictionary size really
-used. The option @samp{-0} is special and only requires about 1.5 MiB at
-most. The amount of memory required for decompression is only a few tens
-of KiB larger than the dictionary size really used.
+Lzip is able to compress and decompress streams of unlimited size by
+automatically creating multi-member output. The members so created are
+large (about 2^60 bytes each).
+
+The amount of memory required for compression is about 1 or 2 times the
+dictionary size limit (1 if input file size is less than dictionary size
+limit, else 2) plus 9 times the dictionary size really used. The option
+@samp{-0} is special and only requires about 1.5 MiB at most. The amount
+of memory required for decompression is only a few tens of KiB larger
+than the dictionary size really used.
Lzip will automatically use the smallest possible dictionary size
without exceeding the given limit. Keep in mind that the decompression
@@ -348,6 +353,11 @@ Table of SI and binary prefixes (unit multipliers):
@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
+---+
@@ -383,15 +393,16 @@ 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.@*
Valid values for dictionary size range from 4KiB to 512MiB.
@item Lzma stream
@@ -405,8 +416,9 @@ 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
@@ -419,8 +431,8 @@ WARNING! Even if lzip is bug-free, other causes may result in a corrupt
compressed file (bugs in the system libraries, memory errors, etc).
Therefore, if the data you are going to compress is important, give the
@samp{--keep} option to lzip and do not remove the original file until
-you verify the compressed file with a command like @w{@samp{lzip -cd
-file.lz | cmp file -}}.
+you verify the compressed file with a command like
+@w{@samp{lzip -cd file.lz | cmp file -}}.
@sp 1
@noindent