1 package IO::Compress::Deflate ;
9 use IO::Compress::RawDeflate;
11 use Compress::Raw::Zlib ;
12 use IO::Compress::Zlib::Constants;
13 use IO::Compress::Base::Common qw(createSelfTiedObject);
16 our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $DeflateError);
18 $VERSION = '2.000_10';
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
223 B<WARNING -- This is a Beta release>.
227 =item * DO NOT use in production code.
229 =item * The documentation is incomplete in places.
231 =item * Parts of the interface defined here are tentative.
233 =item * Please report any problems you find.
240 This module provides a Perl interface that allows writing compressed
241 data to files or buffer as defined in RFC 1950.
251 For reading RFC 1950 files/buffers, see the companion module
252 L<IO::Uncompress::Inflate|IO::Uncompress::Inflate>.
255 =head1 Functional Interface
257 A top-level function, C<deflate>, is provided to carry out
258 "one-shot" compression between buffers and/or files. For finer
259 control over the compression process, see the L</"OO Interface">
262 use IO::Compress::Deflate qw(deflate $DeflateError) ;
264 deflate $input => $output [,OPTS]
265 or die "deflate failed: $DeflateError\n";
269 The functional interface needs Perl5.005 or better.
272 =head2 deflate $input => $output [, OPTS]
275 C<deflate> expects at least two parameters, C<$input> and C<$output>.
277 =head3 The C<$input> parameter
279 The parameter, C<$input>, is used to define the source of
280 the uncompressed data.
282 It can take one of the following forms:
288 If the C<$input> parameter is a simple scalar, it is assumed to be a
289 filename. This file will be opened for reading and the input data
290 will be read from it.
294 If the C<$input> parameter is a filehandle, the input data will be
296 The string '-' can be used as an alias for standard input.
298 =item A scalar reference
300 If C<$input> is a scalar reference, the input data will be read
303 =item An array reference
305 If C<$input> is an array reference, each element in the array must be a
308 The input data will be read from each file in turn.
310 The complete array will be walked to ensure that it only
311 contains valid filenames before any data is compressed.
315 =item An Input FileGlob string
317 If C<$input> is a string that is delimited by the characters "<" and ">"
318 C<deflate> will assume that it is an I<input fileglob string>. The
319 input is the list of files that match the fileglob.
321 If the fileglob does not match any files ...
323 See L<File::GlobMapper|File::GlobMapper> for more details.
328 If the C<$input> parameter is any other type, C<undef> will be returned.
332 =head3 The C<$output> parameter
334 The parameter C<$output> is used to control the destination of the
335 compressed data. This parameter can take one of these forms.
341 If the C<$output> parameter is a simple scalar, it is assumed to be a
342 filename. This file will be opened for writing and the compressed
343 data will be written to it.
347 If the C<$output> parameter is a filehandle, the compressed data
348 will be written to it.
349 The string '-' can be used as an alias for standard output.
352 =item A scalar reference
354 If C<$output> is a scalar reference, the compressed data will be
355 stored in C<$$output>.
359 =item An Array Reference
361 If C<$output> is an array reference, the compressed data will be
362 pushed onto the array.
364 =item An Output FileGlob
366 If C<$output> is a string that is delimited by the characters "<" and ">"
367 C<deflate> will assume that it is an I<output fileglob string>. The
368 output is the list of files that match the fileglob.
370 When C<$output> is an fileglob string, C<$input> must also be a fileglob
371 string. Anything else is an error.
375 If the C<$output> parameter is any other type, C<undef> will be returned.
381 When C<$input> maps to multiple files/buffers and C<$output> is a single
382 file/buffer the compressed input files/buffers will all be stored
383 in C<$output> as a single compressed stream.
387 =head2 Optional Parameters
389 Unless specified below, the optional parameters for C<deflate>,
390 C<OPTS>, are the same as those used with the OO interface defined in the
391 L</"Constructor Options"> section below.
395 =item AutoClose =E<gt> 0|1
397 This option applies to any input or output data streams to
398 C<deflate> that are filehandles.
400 If C<AutoClose> is specified, and the value is true, it will result in all
401 input and/or output filehandles being closed once C<deflate> has
404 This parameter defaults to 0.
408 =item BinModeIn =E<gt> 0|1
410 When reading from a file or filehandle, set C<binmode> before reading.
418 =item -Append =E<gt> 0|1
429 To read the contents of the file C<file1.txt> and write the compressed
430 data to the file C<file1.txt.1950>.
434 use IO::Compress::Deflate qw(deflate $DeflateError) ;
436 my $input = "file1.txt";
437 deflate $input => "$input.1950"
438 or die "deflate failed: $DeflateError\n";
441 To read from an existing Perl filehandle, C<$input>, and write the
442 compressed data to a buffer, C<$buffer>.
446 use IO::Compress::Deflate qw(deflate $DeflateError) ;
449 my $input = new IO::File "<file1.txt"
450 or die "Cannot open 'file1.txt': $!\n" ;
452 deflate $input => \$buffer
453 or die "deflate failed: $DeflateError\n";
455 To compress all files in the directory "/my/home" that match "*.txt"
456 and store the compressed data in the same directory
460 use IO::Compress::Deflate qw(deflate $DeflateError) ;
462 deflate '</my/home/*.txt>' => '<*.1950>'
463 or die "deflate failed: $DeflateError\n";
465 and if you want to compress each file one at a time, this will do the trick
469 use IO::Compress::Deflate qw(deflate $DeflateError) ;
471 for my $input ( glob "/my/home/*.txt" )
473 my $output = "$input.1950" ;
474 deflate $input => $output
475 or die "Error compressing '$input': $DeflateError\n";
483 The format of the constructor for C<IO::Compress::Deflate> is shown below
485 my $z = new IO::Compress::Deflate $output [,OPTS]
486 or die "IO::Compress::Deflate failed: $DeflateError\n";
488 It returns an C<IO::Compress::Deflate> object on success and undef on failure.
489 The variable C<$DeflateError> will contain an error message on failure.
491 If you are running Perl 5.005 or better the object, C<$z>, returned from
492 IO::Compress::Deflate can be used exactly like an L<IO::File|IO::File> filehandle.
493 This means that all normal output file operations can be carried out
495 For example, to write to a compressed file/buffer you can use either of
498 $z->print("hello world\n");
499 print $z "hello world\n";
501 The mandatory parameter C<$output> is used to control the destination
502 of the compressed data. This parameter can take one of these forms.
508 If the C<$output> parameter is a simple scalar, it is assumed to be a
509 filename. This file will be opened for writing and the compressed data
510 will be written to it.
514 If the C<$output> parameter is a filehandle, the compressed data will be
516 The string '-' can be used as an alias for standard output.
519 =item A scalar reference
521 If C<$output> is a scalar reference, the compressed data will be stored
526 If the C<$output> parameter is any other type, C<IO::Compress::Deflate>::new will
529 =head2 Constructor Options
531 C<OPTS> is any combination of the following options:
535 =item AutoClose =E<gt> 0|1
537 This option is only valid when the C<$output> parameter is a filehandle. If
538 specified, and the value is true, it will result in the C<$output> being
539 closed once either the C<close> method is called or the C<IO::Compress::Deflate>
542 This parameter defaults to 0.
544 =item Append =E<gt> 0|1
546 Opens C<$output> in append mode.
548 The behaviour of this option is dependent on the type of C<$output>.
554 If C<$output> is a buffer and C<Append> is enabled, all compressed data
555 will be append to the end if C<$output>. Otherwise C<$output> will be
556 cleared before any data is written to it.
560 If C<$output> is a filename and C<Append> is enabled, the file will be
561 opened in append mode. Otherwise the contents of the file, if any, will be
562 truncated before any compressed data is written to it.
566 If C<$output> is a filehandle, the file pointer will be positioned to the
567 end of the file via a call to C<seek> before any compressed data is written
568 to it. Otherwise the file pointer will not be moved.
572 This parameter defaults to 0.
578 =item Merge =E<gt> 0|1
580 This option is used to compress input data and append it to an existing
581 compressed data stream in C<$output>. The end result is a single compressed
582 data stream stored in C<$output>.
586 It is a fatal error to attempt to use this option when C<$output> is not an
587 RFC 1950 data stream.
591 There are a number of other limitations with the C<Merge> option:
597 This module needs to have been built with zlib 1.2.1 or better to work. A
598 fatal error will be thrown if C<Merge> is used with an older version of
603 If C<$output> is a file or a filehandle, it must be seekable.
608 This parameter defaults to 0.
614 Defines the compression level used by zlib. The value should either be
615 a number between 0 and 9 (0 means no compression and 9 is maximum
616 compression), or one of the symbolic constants defined below.
621 Z_DEFAULT_COMPRESSION
623 The default is Z_DEFAULT_COMPRESSION.
625 Note, these constants are not imported by C<IO::Compress::Deflate> by default.
627 use IO::Compress::Deflate qw(:strategy);
628 use IO::Compress::Deflate qw(:constants);
629 use IO::Compress::Deflate qw(:all);
633 Defines the strategy used to tune the compression. Use one of the symbolic
634 constants defined below.
642 The default is Z_DEFAULT_STRATEGY.
649 =item -Strict =E<gt> 0|1
653 This is a placeholder option.
672 Compresses and outputs the contents of the C<$data> parameter. This
673 has the same behaviour as the C<print> built-in.
675 Returns true if successful.
681 $z->printf($format, $data)
682 printf $z $format, $data
684 Compresses and outputs the contents of the C<$data> parameter.
686 Returns true if successful.
693 $z->syswrite $data, $length
694 $z->syswrite $data, $length, $offset
696 Compresses and outputs the contents of the C<$data> parameter.
698 Returns the number of uncompressed bytes written, or C<undef> if
706 $z->write $data, $length
707 $z->write $data, $length, $offset
709 Compresses and outputs the contents of the C<$data> parameter.
711 Returns the number of uncompressed bytes written, or C<undef> if
720 $z->flush($flush_type);
723 Flushes any pending compressed data to the output file/buffer.
726 This method takes an optional parameter, C<$flush_type>, that controls
727 how the flushing will be carried out. By default the C<$flush_type>
728 used is C<Z_FINISH>. Other valid values for C<$flush_type> are
729 C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is
730 strongly recommended that you only set the C<flush_type> parameter if
731 you fully understand the implications of what it does - overuse of C<flush>
732 can seriously degrade the level of compression achieved. See the C<zlib>
733 documentation for details.
736 Returns true on success.
746 Returns the uncompressed file offset.
757 Returns true if the C<close> method has been called.
763 $z->seek($position, $whence);
764 seek($z, $position, $whence);
769 Provides a sub-set of the C<seek> functionality, with the restriction
770 that it is only legal to seek forward in the output file/buffer.
771 It is a fatal error to attempt to seek backward.
773 Empty parts of the file/buffer will have NULL (0x00) bytes written to them.
777 The C<$whence> parameter takes one the usual values, namely SEEK_SET,
778 SEEK_CUR or SEEK_END.
780 Returns 1 on success, 0 on failure.
789 This is a noop provided for completeness.
795 Returns true if the object currently refers to a opened file/buffer.
799 my $prev = $z->autoflush()
800 my $prev = $z->autoflush(EXPR)
802 If the C<$z> object is associated with a file or a filehandle, this method
803 returns the current autoflush setting for the underlying filehandle. If
804 C<EXPR> is present, and is non-zero, it will enable flushing after every
805 write/print operation.
807 If C<$z> is associated with a buffer, this method has no effect and always
810 B<Note> that the special variable C<$|> B<cannot> be used to set or
811 retrieve the autoflush setting.
813 =head2 input_line_number
815 $z->input_line_number()
816 $z->input_line_number(EXPR)
819 This method always returns C<undef> when compressing.
828 If the C<$z> object is associated with a file or a filehandle, this method
829 will return the underlying file descriptor.
831 If the C<$z> object is is associated with a buffer, this method will
841 Flushes any pending compressed data and then closes the output file/buffer.
845 For most versions of Perl this method will be automatically invoked if
846 the IO::Compress::Deflate object is destroyed (either explicitly or by the
847 variable with the reference to the object going out of scope). The
848 exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In
849 these cases, the C<close> method will be called automatically, but
850 not until global destruction of all live objects when the program is
853 Therefore, if you want your scripts to be able to run on all versions
854 of Perl, you should call C<close> explicitly and not rely on automatic
857 Returns true on success, otherwise 0.
859 If the C<AutoClose> option has been enabled when the IO::Compress::Deflate
860 object was created, and the object is associated with a file, the
861 underlying file will also be closed.
866 =head2 newStream([OPTS])
870 $z->newStream( [OPTS] )
872 Closes the current compressed data stream and starts a new one.
874 OPTS consists of the following sub-set of the the options that are
875 available when creating the C<$z> object,
900 A number of symbolic constants are required by some methods in
901 C<IO::Compress::Deflate>. None are imported by default.
910 Imports C<deflate>, C<$DeflateError> and all symbolic
911 constants that can be used by C<IO::Compress::Deflate>. Same as doing this
913 use IO::Compress::Deflate qw(deflate $DeflateError :constants) ;
917 Import all symbolic constants. Same as doing this
919 use IO::Compress::Deflate qw(:flush :level :strategy) ;
923 These symbolic constants are used by the C<flush> method.
934 These symbolic constants are used by the C<Level> option in the constructor.
939 Z_DEFAULT_COMPRESSION
944 These symbolic constants are used by the C<Strategy> option in the constructor.
968 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::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress>
970 L<Compress::Zlib::FAQ|Compress::Zlib::FAQ>
972 L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>,
973 L<Archive::Tar|Archive::Tar>,
977 For RFC 1950, 1951 and 1952 see
978 F<http://www.faqs.org/rfcs/rfc1950.html>,
979 F<http://www.faqs.org/rfcs/rfc1951.html> and
980 F<http://www.faqs.org/rfcs/rfc1952.html>
982 The I<zlib> compression library was written by Jean-loup Gailly
983 F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>.
985 The primary site for the I<zlib> compression library is
986 F<http://www.zlib.org>.
988 The primary site for gzip is F<http://www.gzip.org>.
995 This module was written by Paul Marquess, F<pmqs@cpan.org>.
999 =head1 MODIFICATION HISTORY
1001 See the Changes file.
1003 =head1 COPYRIGHT AND LICENSE
1005 Copyright (c) 2005-2006 Paul Marquess. All rights reserved.
1007 This program is free software; you can redistribute it and/or
1008 modify it under the same terms as Perl itself.