package IO::Compress::Deflate ; use strict ; use warnings; use bytes; require Exporter ; use IO::Compress::RawDeflate 2.033 ; use Compress::Raw::Zlib 2.033 ; use IO::Compress::Zlib::Constants 2.033 ; use IO::Compress::Base::Common 2.033 qw(createSelfTiedObject); our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $DeflateError); $VERSION = '2.033'; $DeflateError = ''; @ISA = qw(Exporter IO::Compress::RawDeflate); @EXPORT_OK = qw( $DeflateError deflate ) ; %EXPORT_TAGS = %IO::Compress::RawDeflate::DEFLATE_CONSTANTS ; push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ; Exporter::export_ok_tags('all'); sub new { my $class = shift ; my $obj = createSelfTiedObject($class, \$DeflateError); return $obj->_create(undef, @_); } sub deflate { my $obj = createSelfTiedObject(undef, \$DeflateError); return $obj->_def(@_); } sub bitmask($$$$) { my $into = shift ; my $value = shift ; my $offset = shift ; my $mask = shift ; return $into | (($value & $mask) << $offset ) ; } sub mkDeflateHdr($$$;$) { my $method = shift ; my $cinfo = shift; my $level = shift; my $fdict_adler = shift ; my $cmf = 0; my $flg = 0; my $fdict = 0; $fdict = 1 if defined $fdict_adler; $cmf = bitmask($cmf, $method, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS); $cmf = bitmask($cmf, $cinfo, ZLIB_CMF_CINFO_OFFSET, ZLIB_CMF_CINFO_BITS); $flg = bitmask($flg, $fdict, ZLIB_FLG_FDICT_OFFSET, ZLIB_FLG_FDICT_BITS); $flg = bitmask($flg, $level, ZLIB_FLG_LEVEL_OFFSET, ZLIB_FLG_LEVEL_BITS); my $fcheck = 31 - ($cmf * 256 + $flg) % 31 ; $flg = bitmask($flg, $fcheck, ZLIB_FLG_FCHECK_OFFSET, ZLIB_FLG_FCHECK_BITS); my $hdr = pack("CC", $cmf, $flg) ; $hdr .= pack("N", $fdict_adler) if $fdict ; return $hdr; } sub mkHeader { my $self = shift ; my $param = shift ; my $level = $param->value('Level'); my $strategy = $param->value('Strategy'); my $lflag ; $level = 6 if $level == Z_DEFAULT_COMPRESSION ; if (ZLIB_VERNUM >= 0x1210) { if ($strategy >= Z_HUFFMAN_ONLY || $level < 2) { $lflag = ZLIB_FLG_LEVEL_FASTEST } elsif ($level < 6) { $lflag = ZLIB_FLG_LEVEL_FAST } elsif ($level == 6) { $lflag = ZLIB_FLG_LEVEL_DEFAULT } else { $lflag = ZLIB_FLG_LEVEL_SLOWEST } } else { $lflag = ($level - 1) >> 1 ; $lflag = 3 if $lflag > 3 ; } #my $wbits = (MAX_WBITS - 8) << 4 ; my $wbits = 7; mkDeflateHdr(ZLIB_CMF_CM_DEFLATED, $wbits, $lflag); } sub ckParams { my $self = shift ; my $got = shift; $got->value('ADLER32' => 1); return 1 ; } sub mkTrailer { my $self = shift ; return pack("N", *$self->{Compress}->adler32()) ; } sub mkFinalTrailer { return ''; } #sub newHeader #{ # my $self = shift ; # return *$self->{Header}; #} sub getExtraParams { my $self = shift ; return $self->getZlibParams(), } sub getInverseClass { return ('IO::Uncompress::Inflate', \$IO::Uncompress::Inflate::InflateError); } sub getFileInfo { my $self = shift ; my $params = shift; my $file = shift ; } 1; __END__ =head1 NAME IO::Compress::Deflate - Write RFC 1950 files/buffers =head1 SYNOPSIS use IO::Compress::Deflate qw(deflate $DeflateError) ; my $status = deflate $input => $output [,OPTS] or die "deflate failed: $DeflateError\n"; my $z = new IO::Compress::Deflate $output [,OPTS] or die "deflate failed: $DeflateError\n"; $z->print($string); $z->printf($format, $string); $z->write($string); $z->syswrite($string [, $length, $offset]); $z->flush(); $z->tell(); $z->eof(); $z->seek($position, $whence); $z->binmode(); $z->fileno(); $z->opened(); $z->autoflush(); $z->input_line_number(); $z->newStream( [OPTS] ); $z->deflateParams(); $z->close() ; $DeflateError ; # IO::File mode print $z $string; printf $z $format, $string; tell $z eof $z seek $z, $position, $whence binmode $z fileno $z close $z ; =head1 DESCRIPTION This module provides a Perl interface that allows writing compressed data to files or buffer as defined in RFC 1950. For reading RFC 1950 files/buffers, see the companion module L. =head1 Functional Interface A top-level function, C, is provided to carry out "one-shot" compression between buffers and/or files. For finer control over the compression process, see the L section. use IO::Compress::Deflate qw(deflate $DeflateError) ; deflate $input => $output [,OPTS] or die "deflate failed: $DeflateError\n"; The functional interface needs Perl5.005 or better. =head2 deflate $input => $output [, OPTS] C expects at least two parameters, C<$input> and C<$output>. =head3 The C<$input> parameter The parameter, C<$input>, is used to define the source of the uncompressed data. It can take one of the following forms: =over 5 =item A filename If the C<$input> parameter is a simple scalar, it is assumed to be a filename. This file will be opened for reading and the input data will be read from it. =item A filehandle If the C<$input> parameter is a filehandle, the input data will be read from it. The string '-' can be used as an alias for standard input. =item A scalar reference If C<$input> is a scalar reference, the input data will be read from C<$$input>. =item An array reference If C<$input> is an array reference, each element in the array must be a filename. The input data will be read from each file in turn. The complete array will be walked to ensure that it only contains valid filenames before any data is compressed. =item An Input FileGlob string If C<$input> is a string that is delimited by the characters "<" and ">" C will assume that it is an I. The input is the list of files that match the fileglob. See L for more details. =back If the C<$input> parameter is any other type, C will be returned. =head3 The C<$output> parameter The parameter C<$output> is used to control the destination of the compressed data. This parameter can take one of these forms. =over 5 =item A filename If the C<$output> parameter is a simple scalar, it is assumed to be a filename. This file will be opened for writing and the compressed data will be written to it. =item A filehandle If the C<$output> parameter is a filehandle, the compressed data will be written to it. The string '-' can be used as an alias for standard output. =item A scalar reference If C<$output> is a scalar reference, the compressed data will be stored in C<$$output>. =item An Array Reference If C<$output> is an array reference, the compressed data will be pushed onto the array. =item An Output FileGlob If C<$output> is a string that is delimited by the characters "<" and ">" C will assume that it is an I. The output is the list of files that match the fileglob. When C<$output> is an fileglob string, C<$input> must also be a fileglob string. Anything else is an error. See L for more details. =back If the C<$output> parameter is any other type, C will be returned. =head2 Notes When C<$input> maps to multiple files/buffers and C<$output> is a single file/buffer the input files/buffers will be stored in C<$output> as a concatenated series of compressed data streams. =head2 Optional Parameters Unless specified below, the optional parameters for C, C, are the same as those used with the OO interface defined in the L section below. =over 5 =item C<< AutoClose => 0|1 >> This option applies to any input or output data streams to C that are filehandles. If C is specified, and the value is true, it will result in all input and/or output filehandles being closed once C has completed. This parameter defaults to 0. =item C<< BinModeIn => 0|1 >> When reading from a file or filehandle, set C before reading. Defaults to 0. =item C<< Append => 0|1 >> The behaviour of this option is dependent on the type of output data stream. =over 5 =item * A Buffer If C is enabled, all compressed data will be append to the end of the output buffer. Otherwise the output buffer will be cleared before any compressed data is written to it. =item * A Filename If C is enabled, the file will be opened in append mode. Otherwise the contents of the file, if any, will be truncated before any compressed data is written to it. =item * A Filehandle If C is enabled, the filehandle will be positioned to the end of the file via a call to C before any compressed data is written to it. Otherwise the file pointer will not be moved. =back When C is specified, and set to true, it will I all compressed data to the output data stream. So when the output is a filehandle it will carry out a seek to the eof before writing any compressed data. If the output is a filename, it will be opened for appending. If the output is a buffer, all compressed data will be appended to the existing buffer. Conversely when C is not specified, or it is present and is set to false, it will operate as follows. When the output is a filename, it will truncate the contents of the file before writing any compressed data. If the output is a filehandle its position will not be changed. If the output is a buffer, it will be wiped before any compressed data is output. Defaults to 0. =back =head2 Examples To read the contents of the file C and write the compressed data to the file C. use strict ; use warnings ; use IO::Compress::Deflate qw(deflate $DeflateError) ; my $input = "file1.txt"; deflate $input => "$input.1950" or die "deflate failed: $DeflateError\n"; To read from an existing Perl filehandle, C<$input>, and write the compressed data to a buffer, C<$buffer>. use strict ; use warnings ; use IO::Compress::Deflate qw(deflate $DeflateError) ; use IO::File ; my $input = new IO::File " \$buffer or die "deflate failed: $DeflateError\n"; To compress all files in the directory "/my/home" that match "*.txt" and store the compressed data in the same directory use strict ; use warnings ; use IO::Compress::Deflate qw(deflate $DeflateError) ; deflate '' => '<*.1950>' or die "deflate failed: $DeflateError\n"; and if you want to compress each file one at a time, this will do the trick use strict ; use warnings ; use IO::Compress::Deflate qw(deflate $DeflateError) ; for my $input ( glob "/my/home/*.txt" ) { my $output = "$input.1950" ; deflate $input => $output or die "Error compressing '$input': $DeflateError\n"; } =head1 OO Interface =head2 Constructor The format of the constructor for C is shown below my $z = new IO::Compress::Deflate $output [,OPTS] or die "IO::Compress::Deflate failed: $DeflateError\n"; It returns an C object on success and undef on failure. The variable C<$DeflateError> will contain an error message on failure. If you are running Perl 5.005 or better the object, C<$z>, returned from IO::Compress::Deflate can be used exactly like an L filehandle. This means that all normal output file operations can be carried out with C<$z>. For example, to write to a compressed file/buffer you can use either of these forms $z->print("hello world\n"); print $z "hello world\n"; The mandatory parameter C<$output> is used to control the destination of the compressed data. This parameter can take one of these forms. =over 5 =item A filename If the C<$output> parameter is a simple scalar, it is assumed to be a filename. This file will be opened for writing and the compressed data will be written to it. =item A filehandle If the C<$output> parameter is a filehandle, the compressed data will be written to it. The string '-' can be used as an alias for standard output. =item A scalar reference If C<$output> is a scalar reference, the compressed data will be stored in C<$$output>. =back If the C<$output> parameter is any other type, C::new will return undef. =head2 Constructor Options C is any combination of the following options: =over 5 =item C<< AutoClose => 0|1 >> This option is only valid when the C<$output> parameter is a filehandle. If specified, and the value is true, it will result in the C<$output> being closed once either the C method is called or the C object is destroyed. This parameter defaults to 0. =item C<< Append => 0|1 >> Opens C<$output> in append mode. The behaviour of this option is dependent on the type of C<$output>. =over 5 =item * A Buffer If C<$output> is a buffer and C is enabled, all compressed data will be append to the end of C<$output>. Otherwise C<$output> will be cleared before any data is written to it. =item * A Filename If C<$output> is a filename and C is enabled, the file will be opened in append mode. Otherwise the contents of the file, if any, will be truncated before any compressed data is written to it. =item * A Filehandle If C<$output> is a filehandle, the file pointer will be positioned to the end of the file via a call to C before any compressed data is written to it. Otherwise the file pointer will not be moved. =back This parameter defaults to 0. =item C<< Merge => 0|1 >> This option is used to compress input data and append it to an existing compressed data stream in C<$output>. The end result is a single compressed data stream stored in C<$output>. It is a fatal error to attempt to use this option when C<$output> is not an RFC 1950 data stream. There are a number of other limitations with the C option: =over 5 =item 1 This module needs to have been built with zlib 1.2.1 or better to work. A fatal error will be thrown if C is used with an older version of zlib. =item 2 If C<$output> is a file or a filehandle, it must be seekable. =back This parameter defaults to 0. =item -Level Defines the compression level used by zlib. The value should either be a number between 0 and 9 (0 means no compression and 9 is maximum compression), or one of the symbolic constants defined below. Z_NO_COMPRESSION Z_BEST_SPEED Z_BEST_COMPRESSION Z_DEFAULT_COMPRESSION The default is Z_DEFAULT_COMPRESSION. Note, these constants are not imported by C by default. use IO::Compress::Deflate qw(:strategy); use IO::Compress::Deflate qw(:constants); use IO::Compress::Deflate qw(:all); =item -Strategy Defines the strategy used to tune the compression. Use one of the symbolic constants defined below. Z_FILTERED Z_HUFFMAN_ONLY Z_RLE Z_FIXED Z_DEFAULT_STRATEGY The default is Z_DEFAULT_STRATEGY. =item C<< Strict => 0|1 >> This is a placeholder option. =back =head2 Examples TODO =head1 Methods =head2 print Usage is $z->print($data) print $z $data Compresses and outputs the contents of the C<$data> parameter. This has the same behaviour as the C built-in. Returns true if successful. =head2 printf Usage is $z->printf($format, $data) printf $z $format, $data Compresses and outputs the contents of the C<$data> parameter. Returns true if successful. =head2 syswrite Usage is $z->syswrite $data $z->syswrite $data, $length $z->syswrite $data, $length, $offset Compresses and outputs the contents of the C<$data> parameter. Returns the number of uncompressed bytes written, or C if unsuccessful. =head2 write Usage is $z->write $data $z->write $data, $length $z->write $data, $length, $offset Compresses and outputs the contents of the C<$data> parameter. Returns the number of uncompressed bytes written, or C if unsuccessful. =head2 flush Usage is $z->flush; $z->flush($flush_type); Flushes any pending compressed data to the output file/buffer. This method takes an optional parameter, C<$flush_type>, that controls how the flushing will be carried out. By default the C<$flush_type> used is C. Other valid values for C<$flush_type> are C, C, C and C. It is strongly recommended that you only set the C parameter if you fully understand the implications of what it does - overuse of C can seriously degrade the level of compression achieved. See the C documentation for details. Returns true on success. =head2 tell Usage is $z->tell() tell $z Returns the uncompressed file offset. =head2 eof Usage is $z->eof(); eof($z); Returns true if the C method has been called. =head2 seek $z->seek($position, $whence); seek($z, $position, $whence); Provides a sub-set of the C functionality, with the restriction that it is only legal to seek forward in the output file/buffer. It is a fatal error to attempt to seek backward. Empty parts of the file/buffer will have NULL (0x00) bytes written to them. The C<$whence> parameter takes one the usual values, namely SEEK_SET, SEEK_CUR or SEEK_END. Returns 1 on success, 0 on failure. =head2 binmode Usage is $z->binmode binmode $z ; This is a noop provided for completeness. =head2 opened $z->opened() Returns true if the object currently refers to a opened file/buffer. =head2 autoflush my $prev = $z->autoflush() my $prev = $z->autoflush(EXPR) If the C<$z> object is associated with a file or a filehandle, this method returns the current autoflush setting for the underlying filehandle. If C is present, and is non-zero, it will enable flushing after every write/print operation. If C<$z> is associated with a buffer, this method has no effect and always returns C. B that the special variable C<$|> B be used to set or retrieve the autoflush setting. =head2 input_line_number $z->input_line_number() $z->input_line_number(EXPR) This method always returns C when compressing. =head2 fileno $z->fileno() fileno($z) If the C<$z> object is associated with a file or a filehandle, C will return the underlying file descriptor. Once the C method is called C will return C. If the C<$z> object is is associated with a buffer, this method will return C. =head2 close $z->close() ; close $z ; Flushes any pending compressed data and then closes the output file/buffer. For most versions of Perl this method will be automatically invoked if the IO::Compress::Deflate object is destroyed (either explicitly or by the variable with the reference to the object going out of scope). The exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In these cases, the C method will be called automatically, but not until global destruction of all live objects when the program is terminating. Therefore, if you want your scripts to be able to run on all versions of Perl, you should call C explicitly and not rely on automatic closing. Returns true on success, otherwise 0. If the C option has been enabled when the IO::Compress::Deflate object was created, and the object is associated with a file, the underlying file will also be closed. =head2 newStream([OPTS]) Usage is $z->newStream( [OPTS] ) Closes the current compressed data stream and starts a new one. OPTS consists of any of the the options that are available when creating the C<$z> object. See the L section for more details. =head2 deflateParams Usage is $z->deflateParams TODO =head1 Importing A number of symbolic constants are required by some methods in C. None are imported by default. =over 5 =item :all Imports C, C<$DeflateError> and all symbolic constants that can be used by C. Same as doing this use IO::Compress::Deflate qw(deflate $DeflateError :constants) ; =item :constants Import all symbolic constants. Same as doing this use IO::Compress::Deflate qw(:flush :level :strategy) ; =item :flush These symbolic constants are used by the C method. Z_NO_FLUSH Z_PARTIAL_FLUSH Z_SYNC_FLUSH Z_FULL_FLUSH Z_FINISH Z_BLOCK =item :level These symbolic constants are used by the C option in the constructor. Z_NO_COMPRESSION Z_BEST_SPEED Z_BEST_COMPRESSION Z_DEFAULT_COMPRESSION =item :strategy These symbolic constants are used by the C option in the constructor. Z_FILTERED Z_HUFFMAN_ONLY Z_RLE Z_FIXED Z_DEFAULT_STRATEGY =back =head1 EXAMPLES =head2 Apache::GZip Revisited See L =head2 Working with Net::FTP See L =head1 SEE ALSO L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L, L L L, L, L, L For RFC 1950, 1951 and 1952 see F, F and F The I compression library was written by Jean-loup Gailly F and Mark Adler F. The primary site for the I compression library is F. The primary site for gzip is F. =head1 AUTHOR This module was written by Paul Marquess, F. =head1 MODIFICATION HISTORY See the Changes file. =head1 COPYRIGHT AND LICENSE Copyright (c) 2005-2011 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.