1 package IO::Compress::Deflate ;
9 use IO::Compress::RawDeflate 2.003 ;
11 use Compress::Raw::Zlib 2.003 ;
12 use IO::Compress::Zlib::Constants 2.003 ;
13 use IO::Compress::Base::Common 2.003 qw(createSelfTiedObject);
16 our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $DeflateError);
21 @ISA = qw(Exporter IO::Compress::RawDeflate);
22 @EXPORT_OK = qw( $DeflateError deflate ) ;
23 %EXPORT_TAGS = %IO::Compress::RawDeflate::DEFLATE_CONSTANTS ;
24 push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ;
25 Exporter::export_ok_tags('all');
32 my $obj = createSelfTiedObject($class, \$DeflateError);
33 return $obj->_create(undef, @_);
38 my $obj = createSelfTiedObject(undef, \$DeflateError);
39 return $obj->_def(@_);
50 return $into | (($value & $mask) << $offset ) ;
53 sub mkDeflateHdr($$$;$)
58 my $fdict_adler = shift ;
63 $fdict = 1 if defined $fdict_adler;
65 $cmf = bitmask($cmf, $method, ZLIB_CMF_CM_OFFSET, ZLIB_CMF_CM_BITS);
66 $cmf = bitmask($cmf, $cinfo, ZLIB_CMF_CINFO_OFFSET, ZLIB_CMF_CINFO_BITS);
68 $flg = bitmask($flg, $fdict, ZLIB_FLG_FDICT_OFFSET, ZLIB_FLG_FDICT_BITS);
69 $flg = bitmask($flg, $level, ZLIB_FLG_LEVEL_OFFSET, ZLIB_FLG_LEVEL_BITS);
71 my $fcheck = 31 - ($cmf * 256 + $flg) % 31 ;
72 $flg = bitmask($flg, $fcheck, ZLIB_FLG_FCHECK_OFFSET, ZLIB_FLG_FCHECK_BITS);
74 my $hdr = pack("CC", $cmf, $flg) ;
75 $hdr .= pack("N", $fdict_adler) if $fdict ;
85 my $level = $param->value('Level');
86 my $strategy = $param->value('Strategy');
90 if $level == Z_DEFAULT_COMPRESSION ;
92 if (ZLIB_VERNUM >= 0x1210)
94 if ($strategy >= Z_HUFFMAN_ONLY || $level < 2)
95 { $lflag = ZLIB_FLG_LEVEL_FASTEST }
97 { $lflag = ZLIB_FLG_LEVEL_FAST }
99 { $lflag = ZLIB_FLG_LEVEL_DEFAULT }
101 { $lflag = ZLIB_FLG_LEVEL_SLOWEST }
105 $lflag = ($level - 1) >> 1 ;
106 $lflag = 3 if $lflag > 3 ;
109 #my $wbits = (MAX_WBITS - 8) << 4 ;
111 mkDeflateHdr(ZLIB_CMF_CM_DEFLATED, $wbits, $lflag);
119 $got->value('ADLER32' => 1);
127 return pack("N", *$self->{Compress}->adler32()) ;
138 # return *$self->{Header};
144 return $self->getZlibParams(),
149 return ('IO::Uncompress::Inflate',
150 \$IO::Uncompress::Inflate::InflateError);
171 IO::Compress::Deflate - Write RFC 1950 files/buffers
177 use IO::Compress::Deflate qw(deflate $DeflateError) ;
180 my $status = deflate $input => $output [,OPTS]
181 or die "deflate failed: $DeflateError\n";
183 my $z = new IO::Compress::Deflate $output [,OPTS]
184 or die "deflate failed: $DeflateError\n";
187 $z->printf($format, $string);
189 $z->syswrite($string [, $length, $offset]);
193 $z->seek($position, $whence);
198 $z->input_line_number();
199 $z->newStream( [OPTS] );
210 printf $z $format, $string;
213 seek $z, $position, $whence
222 This module provides a Perl interface that allows writing compressed
223 data to files or buffer as defined in RFC 1950.
235 For reading RFC 1950 files/buffers, see the companion module
236 L<IO::Uncompress::Inflate|IO::Uncompress::Inflate>.
239 =head1 Functional Interface
241 A top-level function, C<deflate>, is provided to carry out
242 "one-shot" compression between buffers and/or files. For finer
243 control over the compression process, see the L</"OO Interface">
246 use IO::Compress::Deflate qw(deflate $DeflateError) ;
248 deflate $input => $output [,OPTS]
249 or die "deflate failed: $DeflateError\n";
253 The functional interface needs Perl5.005 or better.
256 =head2 deflate $input => $output [, OPTS]
259 C<deflate> expects at least two parameters, C<$input> and C<$output>.
261 =head3 The C<$input> parameter
263 The parameter, C<$input>, is used to define the source of
264 the uncompressed data.
266 It can take one of the following forms:
272 If the C<$input> parameter is a simple scalar, it is assumed to be a
273 filename. This file will be opened for reading and the input data
274 will be read from it.
278 If the C<$input> parameter is a filehandle, the input data will be
280 The string '-' can be used as an alias for standard input.
282 =item A scalar reference
284 If C<$input> is a scalar reference, the input data will be read
287 =item An array reference
289 If C<$input> is an array reference, each element in the array must be a
292 The input data will be read from each file in turn.
294 The complete array will be walked to ensure that it only
295 contains valid filenames before any data is compressed.
299 =item An Input FileGlob string
301 If C<$input> is a string that is delimited by the characters "<" and ">"
302 C<deflate> will assume that it is an I<input fileglob string>. The
303 input is the list of files that match the fileglob.
305 If the fileglob does not match any files ...
307 See L<File::GlobMapper|File::GlobMapper> for more details.
312 If the C<$input> parameter is any other type, C<undef> will be returned.
316 =head3 The C<$output> parameter
318 The parameter C<$output> is used to control the destination of the
319 compressed data. This parameter can take one of these forms.
325 If the C<$output> parameter is a simple scalar, it is assumed to be a
326 filename. This file will be opened for writing and the compressed
327 data will be written to it.
331 If the C<$output> parameter is a filehandle, the compressed data
332 will be written to it.
333 The string '-' can be used as an alias for standard output.
336 =item A scalar reference
338 If C<$output> is a scalar reference, the compressed data will be
339 stored in C<$$output>.
343 =item An Array Reference
345 If C<$output> is an array reference, the compressed data will be
346 pushed onto the array.
348 =item An Output FileGlob
350 If C<$output> is a string that is delimited by the characters "<" and ">"
351 C<deflate> will assume that it is an I<output fileglob string>. The
352 output is the list of files that match the fileglob.
354 When C<$output> is an fileglob string, C<$input> must also be a fileglob
355 string. Anything else is an error.
359 If the C<$output> parameter is any other type, C<undef> will be returned.
367 When C<$input> maps to multiple files/buffers and C<$output> is a single
368 file/buffer the input files/buffers will be stored
369 in C<$output> as a concatenated series of compressed data streams.
376 =head2 Optional Parameters
378 Unless specified below, the optional parameters for C<deflate>,
379 C<OPTS>, are the same as those used with the OO interface defined in the
380 L</"Constructor Options"> section below.
384 =item C<< AutoClose => 0|1 >>
386 This option applies to any input or output data streams to
387 C<deflate> that are filehandles.
389 If C<AutoClose> is specified, and the value is true, it will result in all
390 input and/or output filehandles being closed once C<deflate> has
393 This parameter defaults to 0.
396 =item C<< BinModeIn => 0|1 >>
398 When reading from a file or filehandle, set C<binmode> before reading.
406 =item C<< Append => 0|1 >>
418 To read the contents of the file C<file1.txt> and write the compressed
419 data to the file C<file1.txt.1950>.
423 use IO::Compress::Deflate qw(deflate $DeflateError) ;
425 my $input = "file1.txt";
426 deflate $input => "$input.1950"
427 or die "deflate failed: $DeflateError\n";
430 To read from an existing Perl filehandle, C<$input>, and write the
431 compressed data to a buffer, C<$buffer>.
435 use IO::Compress::Deflate qw(deflate $DeflateError) ;
438 my $input = new IO::File "<file1.txt"
439 or die "Cannot open 'file1.txt': $!\n" ;
441 deflate $input => \$buffer
442 or die "deflate failed: $DeflateError\n";
444 To compress all files in the directory "/my/home" that match "*.txt"
445 and store the compressed data in the same directory
449 use IO::Compress::Deflate qw(deflate $DeflateError) ;
451 deflate '</my/home/*.txt>' => '<*.1950>'
452 or die "deflate failed: $DeflateError\n";
454 and if you want to compress each file one at a time, this will do the trick
458 use IO::Compress::Deflate qw(deflate $DeflateError) ;
460 for my $input ( glob "/my/home/*.txt" )
462 my $output = "$input.1950" ;
463 deflate $input => $output
464 or die "Error compressing '$input': $DeflateError\n";
472 The format of the constructor for C<IO::Compress::Deflate> is shown below
474 my $z = new IO::Compress::Deflate $output [,OPTS]
475 or die "IO::Compress::Deflate failed: $DeflateError\n";
477 It returns an C<IO::Compress::Deflate> object on success and undef on failure.
478 The variable C<$DeflateError> will contain an error message on failure.
480 If you are running Perl 5.005 or better the object, C<$z>, returned from
481 IO::Compress::Deflate can be used exactly like an L<IO::File|IO::File> filehandle.
482 This means that all normal output file operations can be carried out
484 For example, to write to a compressed file/buffer you can use either of
487 $z->print("hello world\n");
488 print $z "hello world\n";
490 The mandatory parameter C<$output> is used to control the destination
491 of the compressed data. This parameter can take one of these forms.
497 If the C<$output> parameter is a simple scalar, it is assumed to be a
498 filename. This file will be opened for writing and the compressed data
499 will be written to it.
503 If the C<$output> parameter is a filehandle, the compressed data will be
505 The string '-' can be used as an alias for standard output.
508 =item A scalar reference
510 If C<$output> is a scalar reference, the compressed data will be stored
515 If the C<$output> parameter is any other type, C<IO::Compress::Deflate>::new will
518 =head2 Constructor Options
520 C<OPTS> is any combination of the following options:
524 =item C<< AutoClose => 0|1 >>
526 This option is only valid when the C<$output> parameter is a filehandle. If
527 specified, and the value is true, it will result in the C<$output> being
528 closed once either the C<close> method is called or the C<IO::Compress::Deflate>
531 This parameter defaults to 0.
533 =item C<< Append => 0|1 >>
535 Opens C<$output> in append mode.
537 The behaviour of this option is dependent on the type of C<$output>.
543 If C<$output> is a buffer and C<Append> is enabled, all compressed data
544 will be append to the end if C<$output>. Otherwise C<$output> will be
545 cleared before any data is written to it.
549 If C<$output> is a filename and C<Append> is enabled, the file will be
550 opened in append mode. Otherwise the contents of the file, if any, will be
551 truncated before any compressed data is written to it.
555 If C<$output> is a filehandle, the file pointer will be positioned to the
556 end of the file via a call to C<seek> before any compressed data is written
557 to it. Otherwise the file pointer will not be moved.
561 This parameter defaults to 0.
567 =item C<< Merge => 0|1 >>
569 This option is used to compress input data and append it to an existing
570 compressed data stream in C<$output>. The end result is a single compressed
571 data stream stored in C<$output>.
575 It is a fatal error to attempt to use this option when C<$output> is not an
576 RFC 1950 data stream.
580 There are a number of other limitations with the C<Merge> option:
586 This module needs to have been built with zlib 1.2.1 or better to work. A
587 fatal error will be thrown if C<Merge> is used with an older version of
592 If C<$output> is a file or a filehandle, it must be seekable.
597 This parameter defaults to 0.
603 Defines the compression level used by zlib. The value should either be
604 a number between 0 and 9 (0 means no compression and 9 is maximum
605 compression), or one of the symbolic constants defined below.
610 Z_DEFAULT_COMPRESSION
612 The default is Z_DEFAULT_COMPRESSION.
614 Note, these constants are not imported by C<IO::Compress::Deflate> by default.
616 use IO::Compress::Deflate qw(:strategy);
617 use IO::Compress::Deflate qw(:constants);
618 use IO::Compress::Deflate qw(:all);
622 Defines the strategy used to tune the compression. Use one of the symbolic
623 constants defined below.
631 The default is Z_DEFAULT_STRATEGY.
638 =item C<< Strict => 0|1 >>
642 This is a placeholder option.
661 Compresses and outputs the contents of the C<$data> parameter. This
662 has the same behaviour as the C<print> built-in.
664 Returns true if successful.
670 $z->printf($format, $data)
671 printf $z $format, $data
673 Compresses and outputs the contents of the C<$data> parameter.
675 Returns true if successful.
682 $z->syswrite $data, $length
683 $z->syswrite $data, $length, $offset
685 Compresses and outputs the contents of the C<$data> parameter.
687 Returns the number of uncompressed bytes written, or C<undef> if
695 $z->write $data, $length
696 $z->write $data, $length, $offset
698 Compresses and outputs the contents of the C<$data> parameter.
700 Returns the number of uncompressed bytes written, or C<undef> if
709 $z->flush($flush_type);
712 Flushes any pending compressed data to the output file/buffer.
715 This method takes an optional parameter, C<$flush_type>, that controls
716 how the flushing will be carried out. By default the C<$flush_type>
717 used is C<Z_FINISH>. Other valid values for C<$flush_type> are
718 C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is
719 strongly recommended that you only set the C<flush_type> parameter if
720 you fully understand the implications of what it does - overuse of C<flush>
721 can seriously degrade the level of compression achieved. See the C<zlib>
722 documentation for details.
725 Returns true on success.
735 Returns the uncompressed file offset.
746 Returns true if the C<close> method has been called.
752 $z->seek($position, $whence);
753 seek($z, $position, $whence);
758 Provides a sub-set of the C<seek> functionality, with the restriction
759 that it is only legal to seek forward in the output file/buffer.
760 It is a fatal error to attempt to seek backward.
762 Empty parts of the file/buffer will have NULL (0x00) bytes written to them.
766 The C<$whence> parameter takes one the usual values, namely SEEK_SET,
767 SEEK_CUR or SEEK_END.
769 Returns 1 on success, 0 on failure.
778 This is a noop provided for completeness.
784 Returns true if the object currently refers to a opened file/buffer.
788 my $prev = $z->autoflush()
789 my $prev = $z->autoflush(EXPR)
791 If the C<$z> object is associated with a file or a filehandle, this method
792 returns the current autoflush setting for the underlying filehandle. If
793 C<EXPR> is present, and is non-zero, it will enable flushing after every
794 write/print operation.
796 If C<$z> is associated with a buffer, this method has no effect and always
799 B<Note> that the special variable C<$|> B<cannot> be used to set or
800 retrieve the autoflush setting.
802 =head2 input_line_number
804 $z->input_line_number()
805 $z->input_line_number(EXPR)
808 This method always returns C<undef> when compressing.
817 If the C<$z> object is associated with a file or a filehandle, this method
818 will return the underlying file descriptor.
820 If the C<$z> object is is associated with a buffer, this method will
830 Flushes any pending compressed data and then closes the output file/buffer.
834 For most versions of Perl this method will be automatically invoked if
835 the IO::Compress::Deflate object is destroyed (either explicitly or by the
836 variable with the reference to the object going out of scope). The
837 exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In
838 these cases, the C<close> method will be called automatically, but
839 not until global destruction of all live objects when the program is
842 Therefore, if you want your scripts to be able to run on all versions
843 of Perl, you should call C<close> explicitly and not rely on automatic
846 Returns true on success, otherwise 0.
848 If the C<AutoClose> option has been enabled when the IO::Compress::Deflate
849 object was created, and the object is associated with a file, the
850 underlying file will also be closed.
855 =head2 newStream([OPTS])
859 $z->newStream( [OPTS] )
861 Closes the current compressed data stream and starts a new one.
863 OPTS consists of any of the the options that are available when creating
866 See the L</"Constructor Options"> section for more details.
881 A number of symbolic constants are required by some methods in
882 C<IO::Compress::Deflate>. None are imported by default.
891 Imports C<deflate>, C<$DeflateError> and all symbolic
892 constants that can be used by C<IO::Compress::Deflate>. Same as doing this
894 use IO::Compress::Deflate qw(deflate $DeflateError :constants) ;
898 Import all symbolic constants. Same as doing this
901 use IO::Compress::Deflate qw(:flush :level :strategy) ;
906 These symbolic constants are used by the C<flush> method.
917 These symbolic constants are used by the C<Level> option in the constructor.
922 Z_DEFAULT_COMPRESSION
927 These symbolic constants are used by the C<Strategy> option in the constructor.
958 L<Compress::Zlib>, L<IO::Compress::Gzip>, L<IO::Uncompress::Gunzip>, L<IO::Uncompress::Inflate>, L<IO::Compress::RawDeflate>, L<IO::Uncompress::RawInflate>, L<IO::Compress::Bzip2>, L<IO::Uncompress::Bunzip2>, L<IO::Compress::Lzop>, L<IO::Uncompress::UnLzop>, L<IO::Compress::Lzf>, L<IO::Uncompress::UnLzf>, L<IO::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress>
960 L<Compress::Zlib::FAQ|Compress::Zlib::FAQ>
962 L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>,
963 L<Archive::Tar|Archive::Tar>,
967 For RFC 1950, 1951 and 1952 see
968 F<http://www.faqs.org/rfcs/rfc1950.html>,
969 F<http://www.faqs.org/rfcs/rfc1951.html> and
970 F<http://www.faqs.org/rfcs/rfc1952.html>
972 The I<zlib> compression library was written by Jean-loup Gailly
973 F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>.
975 The primary site for the I<zlib> compression library is
976 F<http://www.zlib.org>.
978 The primary site for gzip is F<http://www.gzip.org>.
985 This module was written by Paul Marquess, F<pmqs@cpan.org>.
989 =head1 MODIFICATION HISTORY
991 See the Changes file.
993 =head1 COPYRIGHT AND LICENSE
995 Copyright (c) 2005-2007 Paul Marquess. All rights reserved.
997 This program is free software; you can redistribute it and/or
998 modify it under the same terms as Perl itself.