Provided by: libcompress-raw-lzma-perl_2.074-1build2_amd64 bug

NAME

       Compress::Raw::Lzma - Low-Level Interface to lzma compression library

SYNOPSIS

           use Compress::Raw::Lzma ;

           # Encoders
           my ($lz, $status) = new Compress::Raw::Lzma::EasyEncoder [OPTS]
               or die "Cannot create lzma object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::AloneEncoder [OPTS]
               or die "Cannot create lzma object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::StreamEncoder [OPTS]
               or die "Cannot create lzma object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::RawEncoder [OPTS]
               or die "Cannot create lzma object: $status\n";

           $status = $lz->code($input, $output);
           $status = $lz->flush($output);

           # Decoders
           my ($lz, $status) = new Compress::Raw::Lzma::AloneDecoder [OPTS]
               or die "Cannot create bunzip2 object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::AutoDecoder [OPTS]
               or die "Cannot create bunzip2 object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::StreamDecoder [OPTS]
               or die "Cannot create bunzip2 object: $status\n";

           my ($lz, $status) = new Compress::Raw::Lzma::RawDecoder [OPTS]
               or die "Cannot create bunzip2 object: $status\n";

           $status = $lz->code($input, $output);

           my $version = Compress::Raw::Lzma::lzma_version_number();
           my $version = Compress::Raw::Lzma::lzma_version_string();

DESCRIPTION

       "Compress::Raw::Lzma" provides an interface to the in-memory compression/uncompression
       functions from the lzma compression library.

       Although the primary purpose for the existence of "Compress::Raw::Lzma" is for use by the
       "IO::Compress::Lzma", "IO::Uncompress::UnLzma", "IO::Compress::Xz" and
       "IO::Uncompress::UnXz" modules, it can be used on its own for simple
       compression/uncompression tasks.

       There are two functions, called "code" and "flush", used in all the compression and
       uncompression interfaces defined in this module. By default both of these functions
       overwrites any data stored in its output buffer parameter. If you want to
       compress/uncompress to a single buffer, and have "code" and "flush" append to that buffer,
       enable the "AppendOutput" option when you create the compression/decompression object.

Compression

       There are four compression interfaces available in this module.

       Compress::Raw::Lzma::EasyEncoder =item Compress::Raw::Lzma::AloneEncoder =item
       Compress::Raw::Lzma::StreamEncoder =item Compress::Raw::Lzma::RawEncoder

   ($z, $status) = new Compress::Raw::Lzma::EasyEncoder [OPTS];
       Creates a new xz compression object.

       If successful, it will return the initialised compression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned compression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       Preset => $preset
            Used to choose the compression preset.

            Valid values are 0-9 and "LZMA_PRESET_DEFAULT".

            0 is the fastest compression with the lowest memory usage and the lowest compression.

            9 is the slowest compression with the highest memory usage but with the best
            compression.

            Defaults to "LZMA_PRESET_DEFAULT".

       Extreme => 0|1
            Makes the compression a lot slower, but a small compression gain.

            Defaults to 0.

       Check => $check
            Used to specify the integrity check used in the xz data stream.  Valid values are
            "LZMA_CHECK_NONE", "LZMA_CHECK_CRC32", "LZMA_CHECK_CRC64", "LZMA_CHECK_SHA256".

            Defaults to "LZMA_CHECK_CRC32".

       AppendOutput => 0|1
            Controls whether the compressed data is appended to the output buffer in the "code"
            and "flush" methods.

            Defaults to 0.  (Note in versions of this module prior to 2.072 the defaut value was
            incorrectly documented as 1).

       BufSize => $number
            Sets the initial size for the output buffer used by the "$d->code" method. If the
            buffer has to be reallocated to increase the size, it will grow in increments of
            "Bufsize".

            Defaults to 16k.

   ($z, $status) = new Compress::Raw::Lzma::AloneEncoder [OPTS];
       Creates a legacy lzma compression object. This format is also know as lzma_alone.

       If successful, it will return the initialised compression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned compression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       Filter => $filter
            The  $filter  option must be an object of type "Lzma::Filter::Lzma1".  See
            "Lzma::Filter::Lzma" in Compress::Raw::Lzma for a definition of
            "Lzma::Filter::Lzma1".

            If this option is not present an "Lzma::Filter::Lzma1" object with default values
            will be used.

       AppendOutput => 0|1
            Controls whether the compressed data is appended to the output buffer in the "code"
            and "flush" methods.

            Defaults to 0.  (Note in versions of this module prior to 2.072 the defaut value was
            incorrectly documented as 1).

       BufSize => $number
            Sets the initial size for the output buffer used by the "$d->code" method. If the
            buffer has to be reallocated to increase the size, it will grow in increments of
            "Bufsize".

            Defaults to 16k.

   ($z, $status) = new Compress::Raw::Lzma::StreamEncoder [OPTS];
       Creates a xz compression object.

       If successful, it will return the initialised compression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned compression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       Filter => $filter =item Filter => [$filter1, $filter2,...]
            This option is used to change the bahaviour of the StreamEncoder by applying between
            one and "LZMA_FILTERS_MAX" filters to the data stream during compression. See
            "Filters" for more details on the available filters.

            If this option is present it must either contain a single "Lzma::Filter::Lzma" filter
            object or an array reference containing between one and "LZMA_FILTERS_MAX" filter
            objects.

            If this option is not present an "Lzma::Filter::Lzma2" object with default values
            will be used.

       Check => $check
            Used to specify the integrity check used in the xz data stream.  Valid values are
            "LZMA_CHECK_NONE", "LZMA_CHECK_CRC32", "LZMA_CHECK_CRC64", "LZMA_CHECK_SHA256".

            Defaults to "LZMA_CHECK_CRC32".

       AppendOutput => 0|1
            Controls whether the compressed data is appended to the output buffer in the "code"
            and "flush" methods.

            Defaults to 0.  (Note in versions of this module prior to 2.072 the defaut value was
            incorrectly documented as 1).

       BufSize => $number
            Sets the initial size for the output buffer used by the "$d->code" method. If the
            buffer has to be reallocated to increase the size, it will grow in increments of
            "Bufsize".

            Defaults to 16k.

   ($z, $status) = new Compress::Raw::Lzma::RawEncoder [OPTS];
       Low level access to lzma.

       If successful, it will return the initialised compression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned compression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       Filter => $filter =item Filter => [$filter1, $filter2,...]
            This option is used to change the bahaviour of the RawEncoder by applying between one
            and "LZMA_FILTERS_MAX" filters to the data stream during compression. See "Filters"
            for more details on the available filters.

            If this option is present it must either contain a single "Lzma::Filter::Lzma" filter
            object or an array reference containing between one and "LZMA_FILTERS_MAX" filter
            objects.

            If this option is not present an "Lzma::Filter::Lzma2" object with default values
            will be used.

       AppendOutput => 0|1
            Controls whether the compressed data is appended to the output buffer in the "code"
            and "flush" methods.

            Defaults to 0.  (Note in versions of this module prior to 2.072 the defaut value was
            incorrectly documented as 1).

       BufSize => $number
            Sets the initial size for the output buffer used by the "$d->code" method. If the
            buffer has to be reallocated to increase the size, it will grow in increments of
            "Bufsize".

            Defaults to 16k.

       ForZip => 1/0
            This boolean option is used to enable prefixing the compressed data stream with an
            encoded copy of the filter properties.

            Defaults to 0.

   $status = $lz->code($input, $output);
       Reads the contents of $input, compresses it and writes the compressed data to $output.

       Returns "LZMA_OK" on success and an "lzma" error code on failure.

       If "appendOutput" is enabled in the constructor for the lzma object, the compressed data
       will be appended to $output. If not enabled, $output will be truncated before the
       compressed data is written to it.

   $status = $lz->flush($output, LZMA_FINISH);
       Flushes any pending compressed data to $output. By default it terminates the compressed
       data stream.

       Returns "LZMA_OK" on success and an "lzma" error code on failure.

   Example
       TODO

Uncompression

       There are four uncompression interfaces available in this module.

       Compress::Raw::Lzma::AutoDecoder =item Compress::Raw::Lzma::AloneDecoder =item
       Compress::Raw::Lzma::StreamDecoder =item Compress::Raw::Lzma::RawDecoder

   ($z, $status) = new Compress::Raw::Lzma::AutoDecoder [OPTS] ;
       Create an object that can uncompress any of the compressed data streams that can be
       created by this module.

       If successful, it will return the initialised uncompression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned uncompression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       -MemLimit
            The number of bytes to use when uncompressing.

            Default is unlimited.

       -Bufsize
            Sets the initial size for the output buffer used by the "$i->code" method. If the
            output buffer in this method has to be reallocated to increase the size, it will grow
            in increments of "Bufsize".

            Default is 16k.

       -AppendOutput
            This option controls how data is written to the output buffer by the "$i->code"
            method.

            If the option is set to false, the output buffer in the "$i->code" method will be
            truncated before uncompressed data is written to it.

            If the option is set to true, uncompressed data will be appended to the output buffer
            by the "$i->code" method.

            This option defaults to false.

       -ConsumeInput
            If set to true, this option will remove compressed data from the input buffer of the
            "$i->code" method as the uncompression progresses.

            This option can be useful when you are processing compressed data that is embedded in
            another file/buffer. In this case the data that immediately follows the compressed
            stream will be left in the input buffer.

            This option defaults to true.

       -LimitOutput
            The "LimitOutput" option changes the behavior of the "$i->code" method so that the
            amount of memory used by the output buffer can be limited.

            When "LimitOutput" is used the size of the output buffer used will either be the
            value of the "Bufsize" option or the amount of memory already allocated to $output,
            whichever is larger. Predicting the output size available is tricky, so don't rely on
            getting an exact output buffer size.

            When "LimitOutout" is not specified "$i->code" will use as much memory as it takes to
            write all the uncompressed data it creates by uncompressing the input buffer.

            If "LimitOutput" is enabled, the "ConsumeInput" option will also be enabled.

            This option defaults to false.

            See "The LimitOutput option" for a discussion on why "LimitOutput" is needed and how
            to use it.

   ($z, $status) = new Compress::Raw::Lzma::AloneDecoder [OPTS] ;
       Create an object that can uncompress an lzma_alone data stream.

       If successful, it will return the initialised uncompression object, $z and a $status of
       "LZMA_OK" in a list context. In scalar context it returns the deflation object, $z, only.

       If not successful, the returned uncompression object, $z, will be undef and $status will
       hold the an lzma error code.

       Below is a list of the valid options:

       -MemLimit
            The number of bytes to use when uncompressing.

            Default is unlimited.

       -Bufsize
            Sets the initial size for the output buffer used by the "$i->code" method. If the
            output buffer in this method has to be reallocated to increase the size, it will grow
            in increments of "Bufsize".

            Default is 16k.

       -AppendOutput
            This option controls how data is written to the output buffer by the "$i->code"
            method.

            If the option is set to false, the output buffer in the "$i->code" method will be
            truncated before uncompressed data is written to it.

            If the option is set to true, uncompressed data will be appended to the output buffer
            by the "$i->code" method.

            This option defaults to false.

       -ConsumeInput
            If set to true, this option will remove compressed data from the input buffer of the
            "$i->code" method as the uncompression progresses.

            This option can be useful when you are processing compressed data that is embedded in
            another file/buffer. In this case the data that immediately follows the compressed
            stream will be left in the input buffer.

            This option defaults to true.

       -LimitOutput
            The "LimitOutput" option changes the behavior of the "$i->code" method so that the
            amount of memory used by the output buffer can be limited.

            When "LimitOutput" is used the size of the output buffer used will either be the
            value of the "Bufsize" option or the amount of memory already allocated to $output,
            whichever is larger. Predicting the output size available is tricky, so don't rely on
            getting an exact output buffer size.

            When "LimitOutout" is not specified "$i->code" will use as much memory as it takes to
            write all the uncompressed data it creates by uncompressing the input buffer.

            If "LimitOutput" is enabled, the "ConsumeInput" option will also be enabled.

            This option defaults to false.

            See "The LimitOutput option" for a discussion on why "LimitOutput" is needed and how
            to use it.

   $status = $z->code($input, $output);
       Uncompresses $input and writes the uncompressed data to $output.

       Returns "LZMA_OK" if the uncompression was successful, but the end of the compressed data
       stream has not been reached. Returns "LZMA_STREAM_END" on successful uncompression and the
       end of the compression stream has been reached.

       If "consumeInput" is enabled in the constructor for the lzma object, $input will have all
       compressed data removed from it after uncompression. On "LZMA_OK" return this will mean
       that $input will be an empty string; when "LZMA_STREAM_END" $input will either be an empty
       string or will contain whatever data immediately followed the compressed data stream.

       If "appendOutput" is enabled in the constructor for the lzma object, the uncompressed data
       will be appended to $output. If not enabled, $output will be truncated before the
       uncompressed data is written to it.

Filters

       TODO - more here

       A number of the Lzma compression interfaces (namely "Compress::Raw::Lzma::StreamEncoder" &
       "Compress::Raw::Lzma::AloneEncoder") and the raw lzma uncompression interface make use of
       filters. These filters are used to change the behaviour of compression (and raw
       uncompression).

       All Lzma Filters are sub-classed from the "Lzma::Filter" base-class.

   Lzma::Filter::Lzma
       The "Lzma::Filter::Lzma" class is used to... TODO - more here

       There are two subclasses of "Lzma::Filter::Lzma", namely "Lzma::Filter::Lzma1" and
       "Lzma::Filter::Lzma2".

       The former is typically used with "Compress::Raw::Lzma::AloneEncoder".  The latter with
       "Compress::Raw::Lzma::StreamEncoder".

       When using Lzma filters an "Lzma::Filter::Lzma" must be included and it must be the last
       filter in the chain. There can only be one "Lzma::Filter::Lzma" filter in any filter
       chain.

       The "Lzma::Filter::Lzma" construction takes the following options.

       DictSize => $value
            Dictionary size in bytes. This controls how many bytes of the recently processed
            uncompressed data is kept in memory. The size of the dictionary must be at least
            "LZMA_DICT_SIZE_MIN".

            Defaults to "LZMA_DICT_SIZE_DEFAULT".

       Lc => $value
            Number of literal context bits.

            How many of the highest bits of the previous uncompressed eight-bit byte (also known
            as `literal') are taken into account when predicting the bits of the next literal.

            $value must be a number between "LZMA_LCLP_MIN" and "LZMA_LCLP_MAX".

            Note the sum of the "Lc" and "Lp" options cannot exceed 4.

            Defaults to "LZMA_LC_DEFAULT".

       Lp => $value
            Number of literal position bits.

            How many of the lowest bits of the current position (number of bytes from the
            beginning of the uncompressed data) in the uncompressed data is taken into account
            when predicting the bits of the next literal (a single eight-bit byte).

            Defaults to "LZMA_LP_DEFAULT".

       Pb => $value
            Number of position bits

            How many of the lowest bits of the current position in the uncompressed data is taken
            into account when estimating probabilities of matches. A match is a sequence of bytes
            for which a matching sequence is found from the dictionary and thus can be stored as
            distance-length pair.

            $value must be a number between "LZMA_PB_MIN" and "LZMA_PB_MAX".

            Defaults to "LZMA_PB_DEFAULT".

       Mode => $value
            The Compression Mode. Valid values are "LZMA_MODE_FAST" and "LZMA_MODE_NORMAL".

            Defaults to "LZMA_MODE_NORMAL".

       Nice => $value
            Nice length of a match

            Defaults to 64.

       Mf => $value
            Defines which Match Finder to use. Valid values are "LZMA_MF_HC3" "LZMA_MF_HC4",
            "LZMA_MF_BT2" "LZMA_MF_BT3" and "LZMA_MF_BT4".

            Defaults to "LZMA_MF_BT4".

       Depth => $value
            Maximum search depth in the match finder.

            Defaults to 0.

   Lzma::Filter::BCJ
       The sub-classes of "Lzma::Filter::BCJ" are the Branch/Call/Jump conversion filters. These
       filters are used to rewrite executable binary code for a number of processor
       architectures.  None of these classes take any options.

       Lzma::Filter::X86
            Filter for x86 binaries.

       Lzma::Filter::PowerPC
            Filter for Big endian PowerPC binaries.

       Lzma::Filter::IA64
            Filter for IA64 (Itanium) binaries.

       Lzma::Filter::ARM
            Filter for ARM binaries.

       Lzma::Filter::ARMThumb
            Filter for ARMThumb binaries.

       Lzma::Filter::Sparc
            Filter for Sparc binaries.

   Lzma::Filter::Delta
       Usage is

           Lzma::Filter::Delta [OPTS]

       Type => $type
            Defines the type of Delta calculation. The only available type (and therefore the
            default) is "LZMA_DELTA_TYPE_BYTE",

       Distance => $value
            Defines the Delta Distance. $value must be a number between "LZMA_DELTA_DIST_MIN" and
            "LZMA_DELTA_DIST_MAX".

            Default is "LZMA_DELTA_DIST_MIN".

Misc

   my $version = Compress::Raw::Lzma::lzma_version_number();
       Returns the version of the underlying lzma library this module is using at run-time as a
       number.

   my $version = Compress::Raw::Lzma::lzma_version_string();
       Returns the version of the underlying lzma library this module is using at run-time as a
       string.

   my $version = Compress::Raw::Lzma::LZMA_VERSION();
       Returns the version of the underlying lzma library this module was using at compile-time
       as a number.

   my $version = Compress::Raw::Lzma::LZMA_VERSION_STRING();
       Returns the version of the underlying lzma library this module was using at compile-time
       as a string.

Constants

       The following lzma constants are exported by this module

       TODO - more here

SEE ALSO

       Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip, IO::Compress::Deflate,
       IO::Uncompress::Inflate, IO::Compress::RawDeflate, IO::Uncompress::RawInflate,
       IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzma, IO::Uncompress::UnLzma,
       IO::Compress::Xz, IO::Uncompress::UnXz, IO::Compress::Lzop, IO::Uncompress::UnLzop,
       IO::Compress::Lzf, IO::Uncompress::UnLzf, IO::Uncompress::AnyInflate,
       IO::Uncompress::AnyUncompress

       IO::Compress::FAQ

       File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib

AUTHOR

       This module was written by Paul Marquess, "pmqs@cpan.org".

MODIFICATION HISTORY

       See the Changes file.

COPYRIGHT AND LICENSE

       Copyright (c) 2005-2017 Paul Marquess. All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.