Merging upstream version 1.8.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 208 insertions, 122 deletions

diff --git a/doc/plzip.1 b/doc/plzip.1
index 99dfd8b..694a99d 100644
--- a/doc/plzip.1
+++ b/doc/plzip.1
@@ -1,12 +1,28 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.46.1.
-.TH PLZIP "1" "February 2018" "plzip 1.7" "User Commands"
+.TH PLZIP "1" "January 2019" "plzip 1.8" "User Commands"
 .SH NAME
 plzip \- reduces the size of files
 .SH SYNOPSIS
 .B plzip
 [\fI\,options\/\fR] [\fI\,files\/\fR]
 .SH DESCRIPTION
-Plzip \- Parallel compressor compatible with lzip.
+Plzip is a massively parallel (multi\-threaded) implementation of lzip, fully
+compatible with lzip 1.4 or newer. Plzip uses the lzlib compression library.
+.PP
+Lzip is a lossless data compressor with a user interface similar to the
+one of gzip or bzip2. Lzip can compress about as fast as gzip (lzip \fB\-0\fR)
+or compress most files more than bzip2 (lzip \fB\-9\fR). Decompression speed is
+intermediate between gzip and bzip2. Lzip is better than gzip and bzip2
+from a data recovery perspective. Lzip has been designed, written and
+tested with great care to replace gzip and bzip2 as the standard
+general\-purpose compressed format for unix\-like systems.
+.PP
+Plzip can compress/decompress large files on multiprocessor machines
+much faster than lzip, at the cost of a slightly reduced compression
+ratio (0.4 to 2 percent larger compressed files). 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.
 .SH OPTIONS
 .TP
 \fB\-h\fR, \fB\-\-help\fR
@@ -71,6 +87,12 @@ alias for \fB\-9\fR
 .TP
 \fB\-\-loose\-trailing\fR
 allow trailing data seeming corrupt header
+.TP
+\fB\-\-in\-slots=\fR<n>
+number of 1 MiB input packets buffered [4]
+.TP
+\fB\-\-out\-slots=\fR<n>
+number of 1 MiB output packets buffered [64]
 .PP
 If no file names are given, or if a file is '\-', plzip compresses or
 decompresses from standard input to standard output.
@@ -95,8 +117,8 @@ Plzip home page: http://www.nongnu.org/lzip/plzip.html
 .SH COPYRIGHT
 Copyright \(co 2009 Laszlo Ersek.
 .br
-Copyright \(co 2018 Antonio Diaz Diaz.
-Using lzlib 1.10
+Copyright \(co 2019 Antonio Diaz Diaz.
+Using lzlib 1.11
 License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>
 .br
 This is free software: you are free to change and redistribute it.
diff --git a/doc/plzip.info b/doc/plzip.info
index c8d7387..2b7aa52 100644
--- a/doc/plzip.info
+++ b/doc/plzip.info
@@ -2,7 +2,7 @@ This is plzip.info, produced by makeinfo version 4.13+ from plzip.texi.
 
 INFO-DIR-SECTION Data Compression
 START-INFO-DIR-ENTRY
-* Plzip: (plzip).               Parallel compressor compatible with lzip
+* Plzip: (plzip).               Massively parallel implementation of lzip
 END-INFO-DIR-ENTRY
 
 
@@ -11,7 +11,7 @@ File: plzip.info,  Node: Top,  Next: Introduction,  Up: (dir)
 Plzip Manual
 ************
 
-This manual is for Plzip (version 1.7, 7 February 2018).
+This manual is for Plzip (version 1.8, 5 January 2019).
 
 * Menu:
 
@@ -28,7 +28,7 @@ This manual is for Plzip (version 1.7, 7 February 2018).
 * Concept index::          Index of concepts
 
 
-   Copyright (C) 2009-2018 Antonio Diaz Diaz.
+   Copyright (C) 2009-2019 Antonio Diaz Diaz.
 
    This manual is free documentation: you have unlimited permission to
 copy, distribute and modify it.
@@ -39,20 +39,25 @@ File: plzip.info,  Node: Introduction,  Next: Output,  Prev: Top,  Up: Top
 1 Introduction
 **************
 
-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 is a massively parallel (multi-threaded) implementation of lzip,
+fully compatible with lzip 1.4 or newer. Plzip uses the lzlib
+compression library.
+
+   Lzip is a lossless data compressor with a user interface similar to
+the one of gzip or bzip2. Lzip can compress about as fast as gzip
+(lzip -0) or compress most files more than bzip2 (lzip -9).
+Decompression speed is intermediate between gzip and bzip2. Lzip is
+better than gzip and bzip2 from a data recovery perspective. Lzip has
+been designed, written and tested with great care to replace gzip and
+bzip2 as the standard general-purpose compressed format for unix-like
+systems.
 
    Plzip can compress/decompress large files on multiprocessor machines
 much faster than lzip, at the cost of a slightly reduced compression
 ratio (0.4 to 2 percent larger compressed files). 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 (*note Minimum file sizes::).
-
-   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.
+plzip is no faster than lzip. *Note Minimum file sizes::.
 
    The lzip file format is designed for data sharing and long-term
 archiving, taking into account both data integrity and decoder
@@ -80,15 +85,16 @@ 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 other programs like
-tar or zutils.
+   Plzip uses the same well-defined exit status values used by lzip,
+which makes it safer than compressors returning ambiguous warning
+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
-decompression memory requirement is affected at compression time by the
-choice of dictionary size limit (*note Memory requirements::).
+   Plzip will automatically use for each file the largest dictionary
+size that does not exceed neither the file size nor the limit given.
+Keep in mind that the decompression memory requirement is affected at
+compression time by the choice of dictionary size limit. *Note Memory
+requirements::.
 
    When compressing, plzip replaces every file given in the command line
 with a compressed version of itself, with the name "original_name.lz".
@@ -101,7 +107,7 @@ anyothername   becomes   anyothername.out
 
    (De)compressing a file is much like copying or moving it; therefore
 plzip preserves the access and modification dates, permissions, and,
-when possible, ownership of the file just as "cp -p" does. (If the user
+when possible, ownership of the file just as 'cp -p' does. (If the user
 ID or the group ID can't be duplicated, the file permission bits
 S_ISUID and S_ISGID are cleared).
 
@@ -188,6 +194,7 @@ command line.
 '-V'
 '--version'
      Print the version number of plzip on the standard output and exit.
+     This version number should be included in all bug reports.
 
 '-a'
 '--trailing-error'
@@ -286,12 +293,14 @@ command line.
 '-s BYTES'
 '--dictionary-size=BYTES'
      When compressing, set the dictionary size limit in bytes. Plzip
-     will use the smallest possible dictionary size for each file
-     without exceeding this limit. Valid values range from 4 KiB to
-     512 MiB. Values 12 to 29 are interpreted as powers of two, meaning
-     2^12 to 2^29 bytes. Note that dictionary sizes are quantized. If
-     the specified size does not match one of the valid sizes, it will
-     be rounded upwards by adding up to (BYTES / 8) to it.
+     will use for each file the largest dictionary size that does not
+     exceed neither the file size nor this limit. Valid values range
+     from 4 KiB to 512 MiB. Values 12 to 29 are interpreted as powers
+     of two, meaning 2^12 to 2^29 bytes. Dictionary sizes are quantized
+     so that they can be coded in just one byte (*note
+     coded-dict-size::). If the specified size does not match one of
+     the valid sizes, it will be rounded upwards by adding up to
+     (BYTES / 8) to it.
 
      For maximum compression you should use a dictionary size limit as
      large as possible, but keep in mind that the decompression memory
@@ -320,27 +329,32 @@ command line.
      except for single-member files.
 
 '-0 .. -9'
-     Set the compression parameters (dictionary size and match length
-     limit) as shown in the table below. The default compression level
-     is '-6'.  Note that '-9' can be much slower than '-0'. These
-     options have no effect when decompressing, testing or listing.
+     Compression level. Set the compression parameters (dictionary size
+     and match length limit) as shown in the table below. The default
+     compression level is '-6', equivalent to '-s8MiB -m36'. Note that
+     '-9' can be much slower than '-0'. These options have no effect
+     when decompressing, testing or listing.
 
      The bidimensional parameter space of LZMA can't be mapped to a
      linear scale optimal for all files. If your files are large, very
      repetitive, etc, you may need to use the '--dictionary-size' and
      '--match-length' options directly to achieve optimal performance.
 
-     Level   Dictionary size   Match length limit
-     -0      64 KiB            16 bytes
-     -1      1 MiB             5 bytes
-     -2      1.5 MiB           6 bytes
-     -3      2 MiB             8 bytes
-     -4      3 MiB             12 bytes
-     -5      4 MiB             20 bytes
-     -6      8 MiB             36 bytes
-     -7      16 MiB            68 bytes
-     -8      24 MiB            132 bytes
-     -9      32 MiB            273 bytes
+     If several compression levels or '-s' or '-m' options are given,
+     the last setting is used. For example '-9 -s64MiB' is equivalent
+     to '-s64MiB -m273'
+
+     Level   Dictionary size (-s)   Match length limit (-m)
+     -0      64 KiB                 16 bytes
+     -1      1 MiB                  5 bytes
+     -2      1.5 MiB                6 bytes
+     -3      2 MiB                  8 bytes
+     -4      3 MiB                  12 bytes
+     -5      4 MiB                  20 bytes
+     -6      8 MiB                  36 bytes
+     -7      16 MiB                 68 bytes
+     -8      24 MiB                 132 bytes
+     -9      32 MiB                 273 bytes
 
 '--fast'
 '--best'
@@ -353,6 +367,18 @@ command line.
      if a file triggers a "corrupt header" error and the cause is not
      indeed a corrupt header.
 
+'--in-slots=N'
+     Number of 1 MiB input packets buffered per worker thread when
+     decompressing from non-seekable input. Increasing the number of
+     packets may increase decompression speed, but requires more
+     memory. Valid values range from 1 to 64. The default value is 4.
+
+'--out-slots=N'
+     Number of 1 MiB output packets buffered per worker thread when
+     decompressing to non-seekable output. Increasing the number of
+     packets may increase decompression speed, but requires more
+     memory. Valid values range from 1 to 1024. The default value is 64.
+
 
    Numbers given as arguments to options may be followed by a multiplier
 and an optional 'B' for "byte".
@@ -465,11 +491,11 @@ additional information before, between, or after them.
 
 'DS (coded dictionary size, 1 byte)'
      The dictionary size is calculated by taking a power of 2 (the base
-     size) and substracting from it a fraction between 0/16 and 7/16 of
+     size) and subtracting from it a fraction between 0/16 and 7/16 of
      the base size.
      Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).
-     Bits 7-5 contain the numerator of the fraction (0 to 7) to
-     substract from the base size to obtain the dictionary size.
+     Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
+     from the base size to obtain the dictionary size.
      Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB
      Valid values for dictionary size range from 4 KiB to 512 MiB.
 
@@ -497,22 +523,25 @@ File: plzip.info,  Node: Memory requirements,  Next: Minimum file sizes,  Prev:
 6 Memory required to compress and decompress
 ********************************************
 
-The amount of memory required *per thread* for decompression or testing
-is approximately the following:
+The amount of memory required *per worker thread* for decompression or
+testing is approximately the following:
 
    * For decompression of a regular (seekable) file to another regular
      file, or for testing of a regular file; the dictionary size.
 
    * For testing of a non-seekable file or of standard input; the
-     dictionary size plus up to 5 MiB.
+     dictionary size plus 1 MiB plus up to the number of 1 MiB input
+     packets buffered (4 by default).
 
    * For decompression of a regular file to a non-seekable file or to
-     standard output; the dictionary size plus up to 32 MiB.
+     standard output; the dictionary size plus up to the number of 1 MiB
+     output packets buffered (64 by default).
 
    * For decompression of a non-seekable file or of standard input; the
-     dictionary size plus up to 35 MiB.
+     dictionary size plus 1 MiB plus up to the number of 1 MiB input
+     and output packets buffered (68 by default).
 
-The amount of memory required *per thread* for compression is
+The amount of memory required *per worker thread* for compression is
 approximately the following:
 
    * For compression at level -0; 1.5 MiB plus 3.375 times the data size
@@ -561,7 +590,7 @@ for full use of N processors at a given compression level, using the
 default data size for each level:
 
 Processors   2         4         8         16        64        256
-------------------------------------------------------------------------- 
+------------------------------------------------------------------
 Level                                                          
 -0           2 MiB     4 MiB     8 MiB     16 MiB    64 MiB    256 MiB
 -1           4 MiB     8 MiB     16 MiB    32 MiB    128 MiB   512 MiB
@@ -633,7 +662,11 @@ compressed file (bugs in the system libraries, memory errors, etc).
 Therefore, if the data you are going to compress are important, give the
 '--keep' option to plzip and don't remove the original file until you
 verify the compressed file with a command like
-'plzip -cd file.lz | cmp file -'.
+'plzip -cd file.lz | cmp file -'. Most RAM errors happening during
+compression can only be detected by comparing the compressed file with
+the original because the corruption happens before plzip compresses the
+RAM contents, resulting in a valid compressed file containing wrong
+data.
 
 
 Example 1: Replace a regular file with its compressed version 'file.lz'
@@ -728,21 +761,22 @@ Concept index
 
 
 Tag Table:
-Node: Top221
+Node: Top222
 Node: Introduction1158
-Node: Output5134
-Node: Invoking plzip6614
-Ref: --trailing-error7177
-Ref: --data-size7420
-Node: Program design14938
-Node: File format17090
-Node: Memory requirements19522
-Node: Minimum file sizes20985
-Node: Trailing data23002
-Node: Examples25285
-Ref: concat-example26450
-Node: Problems27025
-Node: Concept index27553
+Node: Output5456
+Node: Invoking plzip6936
+Ref: --trailing-error7563
+Ref: --data-size7806
+Node: Program design16267
+Node: File format18419
+Ref: coded-dict-size19719
+Node: Memory requirements20849
+Node: Minimum file sizes22531
+Node: Trailing data24540
+Node: Examples26823
+Ref: concat-example28238
+Node: Problems28813
+Node: Concept index29341
 
 End Tag Table
 
diff --git a/doc/plzip.texi b/doc/plzip.texi
index 44cff75..b5469b9 100644
--- a/doc/plzip.texi
+++ b/doc/plzip.texi
@@ -6,19 +6,19 @@
 @finalout
 @c %**end of header
 
-@set UPDATED 7 February 2018
-@set VERSION 1.7
+@set UPDATED 5 January 2019
+@set VERSION 1.8
 
 @dircategory Data Compression
 @direntry
-* Plzip: (plzip).               Parallel compressor compatible with lzip
+* Plzip: (plzip).               Massively parallel implementation of lzip
 @end direntry
 
 
 @ifnothtml
 @titlepage
 @title Plzip
-@subtitle Parallel compressor compatible with lzip
+@subtitle Massively parallel implementation of lzip
 @subtitle for Plzip version @value{VERSION}, @value{UPDATED}
 @author by Antonio Diaz Diaz
 
@@ -49,7 +49,7 @@ This manual is for Plzip (version @value{VERSION}, @value{UPDATED}).
 @end menu
 
 @sp 1
-Copyright @copyright{} 2009-2018 Antonio Diaz Diaz.
+Copyright @copyright{} 2009-2019 Antonio Diaz Diaz.
 
 This manual is free documentation: you have unlimited permission
 to copy, distribute and modify it.
@@ -59,23 +59,28 @@ to copy, distribute and modify it.
 @chapter Introduction
 @cindex introduction
 
-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.
+@uref{http://www.nongnu.org/lzip/plzip.html,,Plzip} is a massively parallel
+(multi-threaded) implementation of lzip, fully compatible with lzip 1.4 or
+newer. Plzip uses the lzlib compression library.
+
+@uref{http://www.nongnu.org/lzip/lzip.html,,Lzip} is a lossless data
+compressor with a user interface similar to the one of gzip or bzip2. Lzip
+can compress about as fast as gzip @w{(lzip -0)} or compress most files more
+than bzip2 @w{(lzip -9)}. Decompression speed is intermediate between gzip
+and bzip2. Lzip is better than gzip and bzip2 from a data recovery
+perspective. Lzip has been designed, written and tested with great care to
+replace gzip and bzip2 as the standard general-purpose compressed format for
+unix-like systems.
 
 Plzip can compress/decompress large files on multiprocessor machines
 much faster than lzip, at the cost of a slightly reduced compression
 ratio (0.4 to 2 percent larger compressed files). 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 (@pxref{Minimum file sizes}).
-
-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.
+plzip is no faster than lzip. @xref{Minimum file sizes}.
 
-The lzip file format is designed for data sharing and long-term
-archiving, taking into account both data integrity and decoder
-availability:
+The lzip file format is designed for data sharing and long-term archiving,
+taking into account both data integrity and decoder availability:
 
 @itemize @bullet
 @item
@@ -107,15 +112,14 @@ 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 other programs like
-tar or zutils.
+Plzip uses the same well-defined exit status values used by lzip, which
+makes it safer than compressors returning ambiguous warning 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
-decompression memory requirement is affected at compression time by the
-choice of dictionary size limit (@pxref{Memory requirements}).
+Plzip will automatically use for each file the largest dictionary size that
+does not exceed neither the file size nor the limit given. Keep in mind that
+the decompression memory requirement is affected at compression time by the
+choice of dictionary size limit. @xref{Memory requirements}.
 
 When compressing, plzip replaces every file given in the command line
 with a compressed version of itself, with the name "original_name.lz".
@@ -130,7 +134,7 @@ file from that of the compressed file as follows:
 
 (De)compressing a file is much like copying or moving it; therefore plzip
 preserves the access and modification dates, permissions, and, when
-possible, ownership of the file just as "cp -p" does. (If the user ID or
+possible, ownership of the file just as @samp{cp -p} does. (If the user ID or
 the group ID can't be duplicated, the file permission bits S_ISUID and
 S_ISGID are cleared).
 
@@ -142,10 +146,10 @@ standard input to standard output. In this case, plzip will decline to
 write compressed output to a terminal, as this would be entirely
 incomprehensible and therefore pointless.
 
-Plzip will correctly decompress a file which is the concatenation of two
-or more compressed files. The result is the concatenation of the
-corresponding decompressed files. Integrity testing of concatenated
-compressed files is also supported.
+Plzip will correctly decompress a file which is the concatenation of two or
+more compressed files. The result is the concatenation of the corresponding
+decompressed files. Integrity testing of concatenated compressed files is
+also supported.
 
 
 @node Output
@@ -225,6 +229,7 @@ Print an informative help message describing the options and exit.
 @item -V
 @itemx --version
 Print the version number of plzip on the standard output and exit.
+This version number should be included in all bug reports.
 
 @anchor{--trailing-error}
 @item -a
@@ -322,12 +327,13 @@ Quiet operation. Suppress all messages.
 @item -s @var{bytes}
 @itemx --dictionary-size=@var{bytes}
 When compressing, set the dictionary size limit in bytes. Plzip will use
-the smallest possible dictionary size for each file without exceeding
-this limit. Valid values range from @w{4 KiB} to @w{512 MiB}. Values 12
-to 29 are interpreted as powers of two, meaning 2^12 to 2^29 bytes. Note
-that dictionary sizes are quantized. If the specified size does not
-match one of the valid sizes, it will be rounded upwards by adding up to
-@w{(@var{bytes} / 8)} to it.
+for each file the largest dictionary size that does not exceed neither
+the file size nor this limit. Valid values range from @w{4 KiB} to
+@w{512 MiB}. Values 12 to 29 are interpreted as powers of two, meaning
+2^12 to 2^29 bytes. Dictionary sizes are quantized so that they can be
+coded in just one byte (@pxref{coded-dict-size}). If the specified size
+does not match one of the valid sizes, it will be rounded upwards by
+adding up to @w{(@var{bytes} / 8)} to it.
 
 For maximum compression you should use a dictionary size limit as large
 as possible, but keep in mind that the decompression memory requirement
@@ -354,18 +360,23 @@ Two or more @samp{-v} options show the progress of (de)compression,
 except for single-member files.
 
 @item -0 .. -9
-Set the compression parameters (dictionary size and match length limit)
-as shown in the table below. The default compression level is @samp{-6}.
-Note that @samp{-9} can be much slower than @samp{-0}. These options
-have no effect when decompressing, testing or listing.
+Compression level. Set the compression parameters (dictionary size and
+match length limit) as shown in the table below. The default compression
+level is @samp{-6}, equivalent to @w{@samp{-s8MiB -m36}}. Note that
+@samp{-9} can be much slower than @samp{-0}. These options have no
+effect when decompressing, testing or listing.
 
 The bidimensional parameter space of LZMA can't be mapped to a linear
 scale optimal for all files. If your files are large, very repetitive,
 etc, you may need to use the @samp{--dictionary-size} and
 @samp{--match-length} options directly to achieve optimal performance.
 
-@multitable {Level} {Dictionary size} {Match length limit}
-@item Level @tab Dictionary size @tab Match length limit
+If several compression levels or @samp{-s} or @samp{-m} options are
+given, the last setting is used. For example @w{@samp{-9 -s64MiB}} is
+equivalent to @w{@samp{-s64MiB -m273}}
+
+@multitable {Level} {Dictionary size (-s)} {Match length limit (-m)}
+@item Level @tab Dictionary size (-s) @tab Match length limit (-m)
 @item -0 @tab 64 KiB @tab  16 bytes
 @item -1 @tab  1 MiB @tab   5 bytes
 @item -2 @tab  1.5 MiB @tab   6 bytes
@@ -388,6 +399,18 @@ bytes are so similar to the magic bytes of a lzip header that they can
 be confused with a corrupt header. Use this option if a file triggers a
 "corrupt header" error and the cause is not indeed a corrupt header.
 
+@item --in-slots=@var{n}
+Number of @w{1 MiB} input packets buffered per worker thread when
+decompressing from non-seekable input. Increasing the number of packets
+may increase decompression speed, but requires more memory. Valid values
+range from 1 to 64. The default value is 4.
+
+@item --out-slots=@var{n}
+Number of @w{1 MiB} output packets buffered per worker thread when
+decompressing to non-seekable output. Increasing the number of packets
+may increase decompression speed, but requires more memory. Valid values
+range from 1 to 1024. The default value is 64.
+
 @end table
 
 Numbers given as arguments to options may be followed by a multiplier
@@ -506,12 +529,13 @@ 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. 1 for now.
 
+@anchor{coded-dict-size}
 @item DS (coded dictionary size, 1 byte)
 The dictionary size is calculated by taking a power of 2 (the base size)
-and substracting from it a fraction between 0/16 and 7/16 of the base
+and subtracting from it a fraction between 0/16 and 7/16 of the base
 size.@*
 Bits 4-0 contain the base 2 logarithm of the base size (12 to 29).@*
-Bits 7-5 contain the numerator of the fraction (0 to 7) to substract
+Bits 7-5 contain the numerator of the fraction (0 to 7) to subtract
 from the base size to obtain the dictionary size.@*
 Example: 0xD3 = 2^19 - 6 * 2^15 = 512 KiB - 6 * 32 KiB = 320 KiB@*
 Valid values for dictionary size range from 4 KiB to 512 MiB.
@@ -546,8 +570,8 @@ facilitates safe recovery of undamaged members from multimember files.
 @chapter Memory required to compress and decompress
 @cindex memory requirements
 
-The amount of memory required @strong{per thread} for decompression or
-testing is approximately the following:
+The amount of memory required @strong{per worker thread} for
+decompression or testing is approximately the following:
 
 @itemize @bullet
 @item
@@ -556,20 +580,23 @@ or for testing of a regular file; the dictionary size.
 
 @item
 For testing of a non-seekable file or of standard input; the dictionary
-size plus up to @w{5 MiB}.
+size plus @w{1 MiB} plus up to the number of @w{1 MiB} input packets
+buffered (4 by default).
 
 @item
 For decompression of a regular file to a non-seekable file or to
-standard output; the dictionary size plus up to @w{32 MiB}.
+standard output; the dictionary size plus up to the number of @w{1 MiB}
+output packets buffered (64 by default).
 
 @item
 For decompression of a non-seekable file or of standard input; the
-dictionary size plus up to @w{35 MiB}.
+dictionary size plus @w{1 MiB} plus up to the number of @w{1 MiB} input
+and output packets buffered (68 by default).
 @end itemize
 
 @noindent
-The amount of memory required @strong{per thread} for compression is
-approximately the following:
+The amount of memory required @strong{per worker thread} for compression
+is approximately the following:
 
 @itemize @bullet
 @item
@@ -696,9 +723,12 @@ where a file containing trailing data must be rejected, the option
 WARNING! Even if plzip 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 are important, give the
-@samp{--keep} option to plzip and don't remove the original file until
-you verify the compressed file with a command like
-@w{@samp{plzip -cd file.lz | cmp file -}}.
+@samp{--keep} option to plzip and don't remove the original file until you
+verify the compressed file with a command like
+@w{@samp{plzip -cd file.lz | cmp file -}}. Most RAM errors happening during
+compression can only be detected by comparing the compressed file with the
+original because the corruption happens before plzip compresses the RAM
+contents, resulting in a valid compressed file containing wrong data.
 
 @sp 1
 @noindent