compress::raw::zlib.3

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\&\f(CW\*(C`$d\->dict_adler()\*(C'\fR.
.Sp
The default is no dictionary.
.IP "\fB\-Bufsize\fR" 5
.IX Item "-Bufsize"
Sets the initial size for the output buffer used by the \f(CW\*(C`$d\->deflate\*(C'\fR
and \f(CW\*(C`$d\->flush\*(C'\fR methods. If the buffer has to be
reallocated to increase the size, it will grow in increments of
\&\f(CW\*(C`Bufsize\*(C'\fR.
.Sp
The default buffer size is 4096.
.IP "\fB\-AppendOutput\fR" 5
.IX Item "-AppendOutput"
This option controls how data is written to the output buffer by the
\&\f(CW\*(C`$d\->deflate\*(C'\fR and \f(CW\*(C`$d\->flush\*(C'\fR methods.
.Sp
If the \f(CW\*(C`AppendOutput\*(C'\fR option is set to false, the output buffers in the
\&\f(CW\*(C`$d\->deflate\*(C'\fR and \f(CW\*(C`$d\->flush\*(C'\fR  methods will be truncated before
uncompressed data is written to them.
.Sp
If the option is set to true, uncompressed data will be appended to the
output buffer in the \f(CW\*(C`$d\->deflate\*(C'\fR and \f(CW\*(C`$d\->flush\*(C'\fR methods.
.Sp
This option defaults to false.
.IP "\fB\-CRC32\fR" 5
.IX Item "-CRC32"
If set to true, a crc32 checksum of the uncompressed data will be
calculated. Use the \f(CW\*(C`$d\->crc32\*(C'\fR method to retrieve this value.
.Sp
This option defaults to false.
.IP "\fB\-ADLER32\fR" 5
.IX Item "-ADLER32"
If set to true, an adler32 checksum of the uncompressed data will be
calculated. Use the \f(CW\*(C`$d\->adler32\*(C'\fR method to retrieve this value.
.Sp
This option defaults to false.
.PP
Here is an example of using the \f(CW\*(C`Compress::Raw::Zlib::Deflate\*(C'\fR optional
parameter list to override the default buffer size and compression
level. All other options will take their default values.
.PP
.Vb 2
\&    my $d = new Compress::Raw::Zlib::Deflate ( \-Bufsize => 300, 
\&                                               \-Level   => Z_BEST_SPEED ) ;
.Ve
.ie n .Sh "\fB\fP\fB$status\fP\fB = \fP\f(BI$d\fP\fB\->deflate($input, \fP\f(CB$output\fP\fB)\fP"
.el .Sh "\fB\fP\f(CB$status\fP\fB = \fP\f(CB$d\fP\fB\->deflate($input, \fP\f(CB$output\fP\fB)\fP"
.IX Subsection "$status = $d->deflate($input, $output)"
Deflates the contents of \f(CW$input\fR and writes the compressed data to
\&\f(CW$output\fR.
.PP
The \f(CW$input\fR and \f(CW$output\fR parameters can be either scalars or scalar
references.
.PP
When finished, \f(CW$input\fR will be completely processed (assuming there
were no errors). If the deflation was successful it writes the deflated
data to \f(CW$output\fR and returns a status value of \f(CW\*(C`Z_OK\*(C'\fR.
.PP
On error, it returns a \fIzlib\fR error code.
.PP
If the \f(CW\*(C`AppendOutput\*(C'\fR option is set to true in the constructor for
the \f(CW$d\fR object, the compressed data will be appended to \f(CW$output\fR. If
it is false, \f(CW$output\fR will be truncated before any compressed data is
written to it.
.PP
\&\fBNote\fR: This method will not necessarily write compressed data to
\&\f(CW$output\fR every time it is called. So do not assume that there has been
an error if the contents of \f(CW$output\fR is empty on returning from
this method. As long as the return code from the method is \f(CW\*(C`Z_OK\*(C'\fR,
the deflate has succeeded.
.ie n .Sh "\fB\fP\fB$status\fP\fB = \fP\f(BI$d\fP\fB\->flush($output [, \fP\f(CB$flush_type\fP\fB]) \fP"
.el .Sh "\fB\fP\f(CB$status\fP\fB = \fP\f(CB$d\fP\fB\->flush($output [, \fP\f(CB$flush_type\fP\fB]) \fP"
.IX Subsection "$status = $d->flush($output [, $flush_type]) "
Typically used to finish the deflation. Any pending output will be
written to \f(CW$output\fR.
.PP
Returns \f(CW\*(C`Z_OK\*(C'\fR if successful.
.PP
Note that flushing can seriously degrade the compression ratio, so it
should only be used to terminate a decompression (using \f(CW\*(C`Z_FINISH\*(C'\fR) or
when you want to create a \fIfull flush point\fR (using \f(CW\*(C`Z_FULL_FLUSH\*(C'\fR).
.PP
By default the \f(CW\*(C`flush_type\*(C'\fR used is \f(CW\*(C`Z_FINISH\*(C'\fR. Other valid values
for \f(CW\*(C`flush_type\*(C'\fR are \f(CW\*(C`Z_NO_FLUSH\*(C'\fR, \f(CW\*(C`Z_PARTIAL_FLUSH\*(C'\fR, \f(CW\*(C`Z_SYNC_FLUSH\*(C'\fR
and \f(CW\*(C`Z_FULL_FLUSH\*(C'\fR. It is strongly recommended that you only set the
\&\f(CW\*(C`flush_type\*(C'\fR parameter if you fully understand the implications of
what it does. See the \f(CW\*(C`zlib\*(C'\fR documentation for details.
.PP
If the \f(CW\*(C`AppendOutput\*(C'\fR option is set to true in the constructor for
the \f(CW$d\fR object, the compressed data will be appended to \f(CW$output\fR. If
it is false, \f(CW$output\fR will be truncated before any compressed data is
written to it.
.ie n .Sh "\fB\fP\fB$status\fP\fB = \fP\f(BI$d\fP\fB\->deflateParams([\s-1OPT\s0])\fP"
.el .Sh "\fB\fP\f(CB$status\fP\fB = \fP\f(CB$d\fP\fB\->deflateParams([\s-1OPT\s0])\fP"
.IX Subsection "$status = $d->deflateParams([OPT])"
Change settings for the deflate object \f(CW$d\fR.
.PP
The list of the valid options is shown below. Options not specified
will remain unchanged.
.IP "\fB\-Level\fR" 5
.IX Item "-Level"
Defines the compression level. Valid values are 0 through 9,
\&\f(CW\*(C`Z_NO_COMPRESSION\*(C'\fR, \f(CW\*(C`Z_BEST_SPEED\*(C'\fR, \f(CW\*(C`Z_BEST_COMPRESSION\*(C'\fR, and
\&\f(CW\*(C`Z_DEFAULT_COMPRESSION\*(C'\fR.
.IP "\fB\-Strategy\fR" 5
.IX Item "-Strategy"
Defines the strategy used to tune the compression. The valid values are
\&\f(CW\*(C`Z_DEFAULT_STRATEGY\*(C'\fR, \f(CW\*(C`Z_FILTERED\*(C'\fR and \f(CW\*(C`Z_HUFFMAN_ONLY\*(C'\fR.
.IP "\fB\-BufSize\fR" 5
.IX Item "-BufSize"
Sets the initial size for the output buffer used by the \f(CW\*(C`$d\->deflate\*(C'\fR
and \f(CW\*(C`$d\->flush\*(C'\fR methods. If the buffer has to be
reallocated to increase the size, it will grow in increments of
\&\f(CW\*(C`Bufsize\*(C'\fR.
.ie n .Sh "\fB\fP\fB$status\fP\fB = \fP\f(BI$d\fP\fB\->deflateTune($good_length, \fP\f(CB$max_lazy\fP\fB, \fP\f(CB$nice_length\fP\fB, \fP\f(CB$max_chain\fP\fB)\fP"
.el .Sh "\fB\fP\f(CB$status\fP\fB = \fP\f(CB$d\fP\fB\->deflateTune($good_length, \fP\f(CB$max_lazy\fP\fB, \fP\f(CB$nice_length\fP\fB, \fP\f(CB$max_chain\fP\fB)\fP"
.IX Subsection "$status = $d->deflateTune($good_length, $max_lazy, $nice_length, $max_chain)"
Tune the internal settings for the deflate object \f(CW$d\fR. This option is
only available if you are running zlib 1.2.2.3 or better.
.PP
Refer to the documentation in zlib.h for instructions on how to fly
\&\f(CW\*(C`deflateTune\*(C'\fR.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIdict_adler()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIdict_adler()\fP\fB\fP"
.IX Subsection "$d->dict_adler()"
Returns the adler32 value for the dictionary.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIcrc32()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIcrc32()\fP\fB\fP"
.IX Subsection "$d->crc32()"
Returns the crc32 value for the uncompressed data to date.
.PP
If the \f(CW\*(C`CRC32\*(C'\fR option is not enabled in the constructor for this object,
this method will always return 0;
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIadler32()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIadler32()\fP\fB\fP"
.IX Subsection "$d->adler32()"
Returns the adler32 value for the uncompressed data to date.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BImsg()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BImsg()\fP\fB\fP"
.IX Subsection "$d->msg()"
Returns the last error message generated by zlib.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BItotal_in()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BItotal_in()\fP\fB\fP"
.IX Subsection "$d->total_in()"
Returns the total number of bytes uncompressed bytes input to deflate.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BItotal_out()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BItotal_out()\fP\fB\fP"
.IX Subsection "$d->total_out()"
Returns the total number of compressed bytes output from deflate.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIget_Strategy()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIget_Strategy()\fP\fB\fP"
.IX Subsection "$d->get_Strategy()"
Returns the deflation strategy currently used. Valid values are
\&\f(CW\*(C`Z_DEFAULT_STRATEGY\*(C'\fR, \f(CW\*(C`Z_FILTERED\*(C'\fR and \f(CW\*(C`Z_HUFFMAN_ONLY\*(C'\fR.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIget_Level()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIget_Level()\fP\fB\fP"
.IX Subsection "$d->get_Level()"
Returns the compression level being used.
.ie n .Sh "\fB\fP\fB$d\fP\fB\->\fP\f(BIget_BufSize()\fP\fB\fP"
.el .Sh "\fB\fP\f(CB$d\fP\fB\->\fP\f(BIget_BufSize()\fP\fB\fP"
.IX Subsection "$d->get_BufSize()"
Returns the buffer size used to carry out the compression.
.Sh "Example"
.IX Subsection "Example"
Here is a trivial example of using \f(CW\*(C`deflate\*(C'\fR. It simply reads standard
input, deflates it and writes it to standard output.
.PP
.Vb 2
\&    use strict ;
\&    use warnings ;
\&
\&    use Compress::Raw::Zlib ;
\&
\&    binmode STDIN;
\&    binmode STDOUT;
\&    my $x = new Compress::Raw::Zlib::Deflate
\&       or die "Cannot create a deflation stream\en" ;
\&
\&    my ($output, $status) ;
\&    while (<>)
\&    {
\&        $status = $x\->deflate($_, $output) ;
\&    
\&        $status == Z_OK
\&            or die "deflation failed\en" ;
\&    
\&        print $output ;
\&    }
\&    
\&    $status = $x\->flush($output) ;
\&    
\&    $status == Z_OK
\&        or die "deflation failed\en" ;
\&    
\&    print $output ;
.Ve
.SH "Compress::Raw::Zlib::Inflate"
.IX Header "Compress::Raw::Zlib::Inflate"
This section defines an interface that allows in-memory uncompression using
the \fIinflate\fR interface provided by zlib.
.PP
Here is a definition of the interface:
.ie n .Sh "\fB ($i, \fP\fB$status\fP\fB) = new Compress::Raw::Zlib::Inflate( [\s-1OPT\s0] ) \fP"
.el .Sh "\fB ($i, \fP\f(CB$status\fP\fB) = new Compress::Raw::Zlib::Inflate( [\s-1OPT\s0] ) \fP"
.IX Subsection " ($i, $status) = new Compress::Raw::Zlib::Inflate( [OPT] ) "
Initialises an inflation object.
.PP
In a list context it returns the inflation object, \f(CW$i\fR, and the
\&\fIzlib\fR status code (\f(CW$status\fR). In a scalar context it returns the
inflation object only.
.PP
If successful, \f(CW$i\fR will hold the inflation object and \f(CW$status\fR will
be \f(CW\*(C`Z_OK\*(C'\fR.
.PP
If not successful, \f(CW$i\fR will be \fIundef\fR and \f(CW$status\fR will hold the
\&\fIzlib\fR error code.
.PP
The function optionally takes a number of named options specified as
\&\f(CW\*(C`\-Name => value\*(C'\fR pairs. This allows individual options to be
tailored without having to specify them all in the parameter list.
.PP
For backward compatibility, it is also possible to pass the parameters
as a reference to a hash containing the \f(CW\*(C`name=>value\*(C'\fR pairs.
.PP
Here is a list of the valid options:
.IP "\fB\-WindowBits\fR" 5
.IX Item "-WindowBits"
To uncompress an \s-1RFC\s0 1950 data stream, set \f(CW\*(C`WindowBits\*(C'\fR to a positive
number.
.Sp
To uncompress an \s-1RFC\s0 1951 data stream, set \f(CW\*(C`WindowBits\*(C'\fR to \f(CW\*(C`\-MAX_WBITS\*(C'\fR.
.Sp
For a full definition of the meaning and valid values for \f(CW\*(C`WindowBits\*(C'\fR
refer to the \fIzlib\fR documentation for \fIinflateInit2\fR.
.Sp
Defaults to \s-1MAX_WBITS\s0.
.IP "\fB\-Bufsize\fR" 5
.IX Item "-Bufsize"
Sets the initial size for the output buffer used by the \f(CW\*(C`$i\->inflate\*(C'\fR
method. If the output buffer in this method has to be reallocated to
increase the size, it will grow in increments of \f(CW\*(C`Bufsize\*(C'\fR.
.Sp
Default is 4096.
.IP "\fB\-Dictionary\fR" 5
.IX Item "-Dictionary"
The default is no dictionary.
.IP "\fB\-AppendOutput\fR" 5
.IX Item "-AppendOutput"
This option controls how data is written to the output buffer by the
\&\f(CW\*(C`$i\->inflate\*(C'\fR method.
.Sp