Commit | Line | Data |
25f0751f |
1 | package IO::Compress::Deflate ; |
2 | |
3 | use strict ; |
4 | use warnings; |
5 | use bytes; |
6 | |
7 | require Exporter ; |
8 | |
9 | use IO::Compress::RawDeflate; |
10 | |
11 | use Compress::Raw::Zlib ; |
12 | use IO::Compress::Zlib::Constants; |
13 | use IO::Compress::Base::Common qw(createSelfTiedObject); |
14 | |
15 | |
16 | our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, $DeflateError); |
17 | |
c70c1701 |
18 | $VERSION = '2.000_12'; |
25f0751f |
19 | $DeflateError = ''; |
20 | |
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'); |
26 | |
27 | |
28 | sub new |
29 | { |
30 | my $class = shift ; |
31 | |
32 | my $obj = createSelfTiedObject($class, \$DeflateError); |
33 | return $obj->_create(undef, @_); |
34 | } |
35 | |
36 | sub deflate |
37 | { |
38 | my $obj = createSelfTiedObject(undef, \$DeflateError); |
39 | return $obj->_def(@_); |
40 | } |
41 | |
42 | |
43 | sub bitmask($$$$) |
44 | { |
45 | my $into = shift ; |
46 | my $value = shift ; |
47 | my $offset = shift ; |
48 | my $mask = shift ; |
49 | |
50 | return $into | (($value & $mask) << $offset ) ; |
51 | } |
52 | |
53 | sub mkDeflateHdr($$$;$) |
54 | { |
55 | my $method = shift ; |
56 | my $cinfo = shift; |
57 | my $level = shift; |
58 | my $fdict_adler = shift ; |
59 | |
60 | my $cmf = 0; |
61 | my $flg = 0; |
62 | my $fdict = 0; |
63 | $fdict = 1 if defined $fdict_adler; |
64 | |
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); |
67 | |
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); |
70 | |
71 | my $fcheck = 31 - ($cmf * 256 + $flg) % 31 ; |
72 | $flg = bitmask($flg, $fcheck, ZLIB_FLG_FCHECK_OFFSET, ZLIB_FLG_FCHECK_BITS); |
73 | |
74 | my $hdr = pack("CC", $cmf, $flg) ; |
75 | $hdr .= pack("N", $fdict_adler) if $fdict ; |
76 | |
77 | return $hdr; |
78 | } |
79 | |
80 | sub mkHeader |
81 | { |
82 | my $self = shift ; |
83 | my $param = shift ; |
84 | |
85 | my $level = $param->value('Level'); |
86 | my $strategy = $param->value('Strategy'); |
87 | |
88 | my $lflag ; |
89 | $level = 6 |
90 | if $level == Z_DEFAULT_COMPRESSION ; |
91 | |
92 | if (ZLIB_VERNUM >= 0x1210) |
93 | { |
94 | if ($strategy >= Z_HUFFMAN_ONLY || $level < 2) |
95 | { $lflag = ZLIB_FLG_LEVEL_FASTEST } |
96 | elsif ($level < 6) |
97 | { $lflag = ZLIB_FLG_LEVEL_FAST } |
98 | elsif ($level == 6) |
99 | { $lflag = ZLIB_FLG_LEVEL_DEFAULT } |
100 | else |
101 | { $lflag = ZLIB_FLG_LEVEL_SLOWEST } |
102 | } |
103 | else |
104 | { |
105 | $lflag = ($level - 1) >> 1 ; |
106 | $lflag = 3 if $lflag > 3 ; |
107 | } |
108 | |
109 | #my $wbits = (MAX_WBITS - 8) << 4 ; |
110 | my $wbits = 7; |
111 | mkDeflateHdr(ZLIB_CMF_CM_DEFLATED, $wbits, $lflag); |
112 | } |
113 | |
114 | sub ckParams |
115 | { |
116 | my $self = shift ; |
117 | my $got = shift; |
118 | |
119 | $got->value('ADLER32' => 1); |
120 | return 1 ; |
121 | } |
122 | |
123 | |
124 | sub mkTrailer |
125 | { |
126 | my $self = shift ; |
127 | return pack("N", *$self->{Compress}->adler32()) ; |
128 | } |
129 | |
130 | sub mkFinalTrailer |
131 | { |
132 | return ''; |
133 | } |
134 | |
135 | #sub newHeader |
136 | #{ |
137 | # my $self = shift ; |
138 | # return *$self->{Header}; |
139 | #} |
140 | |
141 | sub getExtraParams |
142 | { |
143 | my $self = shift ; |
144 | return $self->getZlibParams(), |
145 | } |
146 | |
147 | sub getInverseClass |
148 | { |
149 | return ('IO::Uncompress::Inflate', |
150 | \$IO::Uncompress::Inflate::InflateError); |
151 | } |
152 | |
153 | sub getFileInfo |
154 | { |
155 | my $self = shift ; |
156 | my $params = shift; |
157 | my $file = shift ; |
158 | |
159 | } |
160 | |
161 | |
162 | |
163 | 1; |
164 | |
165 | __END__ |
166 | |
167 | =head1 NAME |
168 | |
169 | |
cb7abd7f |
170 | |
171 | IO::Compress::Deflate - Write RFC 1950 files/buffers |
172 | |
25f0751f |
173 | |
174 | |
175 | =head1 SYNOPSIS |
176 | |
177 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
178 | |
179 | |
180 | my $status = deflate $input => $output [,OPTS] |
181 | or die "deflate failed: $DeflateError\n"; |
182 | |
183 | my $z = new IO::Compress::Deflate $output [,OPTS] |
184 | or die "deflate failed: $DeflateError\n"; |
185 | |
186 | $z->print($string); |
187 | $z->printf($format, $string); |
188 | $z->write($string); |
189 | $z->syswrite($string [, $length, $offset]); |
190 | $z->flush(); |
191 | $z->tell(); |
192 | $z->eof(); |
193 | $z->seek($position, $whence); |
194 | $z->binmode(); |
195 | $z->fileno(); |
196 | $z->opened(); |
197 | $z->autoflush(); |
198 | $z->input_line_number(); |
199 | $z->newStream( [OPTS] ); |
200 | |
201 | $z->deflateParams(); |
202 | |
203 | $z->close() ; |
204 | |
205 | $DeflateError ; |
206 | |
207 | # IO::File mode |
208 | |
209 | print $z $string; |
210 | printf $z $format, $string; |
211 | tell $z |
212 | eof $z |
213 | seek $z, $position, $whence |
214 | binmode $z |
215 | fileno $z |
216 | close $z ; |
217 | |
218 | |
219 | =head1 DESCRIPTION |
220 | |
221 | |
222 | |
223 | B<WARNING -- This is a Beta release>. |
224 | |
225 | =over 5 |
226 | |
227 | =item * DO NOT use in production code. |
228 | |
229 | =item * The documentation is incomplete in places. |
230 | |
231 | =item * Parts of the interface defined here are tentative. |
232 | |
233 | =item * Please report any problems you find. |
234 | |
235 | =back |
236 | |
237 | |
238 | |
239 | |
240 | This module provides a Perl interface that allows writing compressed |
241 | data to files or buffer as defined in RFC 1950. |
242 | |
243 | |
244 | |
245 | |
246 | |
247 | |
248 | |
249 | |
250 | |
251 | For reading RFC 1950 files/buffers, see the companion module |
252 | L<IO::Uncompress::Inflate|IO::Uncompress::Inflate>. |
253 | |
254 | |
255 | =head1 Functional Interface |
256 | |
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"> |
260 | section. |
261 | |
262 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
263 | |
264 | deflate $input => $output [,OPTS] |
265 | or die "deflate failed: $DeflateError\n"; |
266 | |
267 | |
268 | |
269 | The functional interface needs Perl5.005 or better. |
270 | |
271 | |
272 | =head2 deflate $input => $output [, OPTS] |
273 | |
274 | |
275 | C<deflate> expects at least two parameters, C<$input> and C<$output>. |
276 | |
277 | =head3 The C<$input> parameter |
278 | |
279 | The parameter, C<$input>, is used to define the source of |
280 | the uncompressed data. |
281 | |
282 | It can take one of the following forms: |
283 | |
284 | =over 5 |
285 | |
286 | =item A filename |
287 | |
288 | If the C<$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. |
291 | |
292 | =item A filehandle |
293 | |
294 | If the C<$input> parameter is a filehandle, the input data will be |
295 | read from it. |
296 | The string '-' can be used as an alias for standard input. |
297 | |
298 | =item A scalar reference |
299 | |
300 | If C<$input> is a scalar reference, the input data will be read |
301 | from C<$$input>. |
302 | |
303 | =item An array reference |
304 | |
305 | If C<$input> is an array reference, each element in the array must be a |
306 | filename. |
307 | |
308 | The input data will be read from each file in turn. |
309 | |
310 | The complete array will be walked to ensure that it only |
311 | contains valid filenames before any data is compressed. |
312 | |
313 | |
314 | |
315 | =item An Input FileGlob string |
316 | |
317 | If C<$input> is a string that is delimited by the characters "<" and ">" |
318 | C<deflate> will assume that it is an I<input fileglob string>. The |
319 | input is the list of files that match the fileglob. |
320 | |
321 | If the fileglob does not match any files ... |
322 | |
323 | See L<File::GlobMapper|File::GlobMapper> for more details. |
324 | |
325 | |
326 | =back |
327 | |
328 | If the C<$input> parameter is any other type, C<undef> will be returned. |
329 | |
330 | |
331 | |
332 | =head3 The C<$output> parameter |
333 | |
334 | The parameter C<$output> is used to control the destination of the |
335 | compressed data. This parameter can take one of these forms. |
336 | |
337 | =over 5 |
338 | |
339 | =item A filename |
340 | |
341 | If the C<$output> parameter is a simple scalar, it is assumed to be a |
342 | filename. This file will be opened for writing and the compressed |
343 | data will be written to it. |
344 | |
345 | =item A filehandle |
346 | |
347 | If the C<$output> parameter is a filehandle, the compressed data |
348 | will be written to it. |
349 | The string '-' can be used as an alias for standard output. |
350 | |
351 | |
352 | =item A scalar reference |
353 | |
354 | If C<$output> is a scalar reference, the compressed data will be |
355 | stored in C<$$output>. |
356 | |
357 | |
358 | |
359 | =item An Array Reference |
360 | |
361 | If C<$output> is an array reference, the compressed data will be |
362 | pushed onto the array. |
363 | |
364 | =item An Output FileGlob |
365 | |
366 | If C<$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. |
369 | |
370 | When C<$output> is an fileglob string, C<$input> must also be a fileglob |
371 | string. Anything else is an error. |
372 | |
373 | =back |
374 | |
375 | If the C<$output> parameter is any other type, C<undef> will be returned. |
376 | |
377 | |
378 | |
379 | =head2 Notes |
380 | |
c70c1701 |
381 | |
382 | |
25f0751f |
383 | When C<$input> maps to multiple files/buffers and C<$output> is a single |
c70c1701 |
384 | file/buffer the input files/buffers will be stored |
385 | in C<$output> as a concatenated series of compressed data streams. |
386 | |
387 | |
388 | |
25f0751f |
389 | |
390 | |
391 | |
392 | =head2 Optional Parameters |
393 | |
394 | Unless specified below, the optional parameters for C<deflate>, |
395 | C<OPTS>, are the same as those used with the OO interface defined in the |
396 | L</"Constructor Options"> section below. |
397 | |
398 | =over 5 |
399 | |
400 | =item AutoClose =E<gt> 0|1 |
401 | |
402 | This option applies to any input or output data streams to |
403 | C<deflate> that are filehandles. |
404 | |
405 | If C<AutoClose> is specified, and the value is true, it will result in all |
406 | input and/or output filehandles being closed once C<deflate> has |
407 | completed. |
408 | |
409 | This parameter defaults to 0. |
410 | |
411 | |
412 | |
413 | =item BinModeIn =E<gt> 0|1 |
414 | |
415 | When reading from a file or filehandle, set C<binmode> before reading. |
416 | |
417 | Defaults to 0. |
418 | |
419 | |
420 | |
421 | |
422 | |
423 | =item -Append =E<gt> 0|1 |
424 | |
425 | TODO |
426 | |
427 | |
428 | =back |
429 | |
430 | |
431 | |
432 | =head2 Examples |
433 | |
434 | To read the contents of the file C<file1.txt> and write the compressed |
435 | data to the file C<file1.txt.1950>. |
436 | |
437 | use strict ; |
438 | use warnings ; |
439 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
440 | |
441 | my $input = "file1.txt"; |
442 | deflate $input => "$input.1950" |
443 | or die "deflate failed: $DeflateError\n"; |
444 | |
445 | |
446 | To read from an existing Perl filehandle, C<$input>, and write the |
447 | compressed data to a buffer, C<$buffer>. |
448 | |
449 | use strict ; |
450 | use warnings ; |
451 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
452 | use IO::File ; |
453 | |
454 | my $input = new IO::File "<file1.txt" |
455 | or die "Cannot open 'file1.txt': $!\n" ; |
456 | my $buffer ; |
457 | deflate $input => \$buffer |
458 | or die "deflate failed: $DeflateError\n"; |
459 | |
460 | To compress all files in the directory "/my/home" that match "*.txt" |
461 | and store the compressed data in the same directory |
462 | |
463 | use strict ; |
464 | use warnings ; |
465 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
466 | |
467 | deflate '</my/home/*.txt>' => '<*.1950>' |
468 | or die "deflate failed: $DeflateError\n"; |
469 | |
470 | and if you want to compress each file one at a time, this will do the trick |
471 | |
472 | use strict ; |
473 | use warnings ; |
474 | use IO::Compress::Deflate qw(deflate $DeflateError) ; |
475 | |
476 | for my $input ( glob "/my/home/*.txt" ) |
477 | { |
478 | my $output = "$input.1950" ; |
479 | deflate $input => $output |
480 | or die "Error compressing '$input': $DeflateError\n"; |
481 | } |
482 | |
483 | |
484 | =head1 OO Interface |
485 | |
486 | =head2 Constructor |
487 | |
488 | The format of the constructor for C<IO::Compress::Deflate> is shown below |
489 | |
490 | my $z = new IO::Compress::Deflate $output [,OPTS] |
491 | or die "IO::Compress::Deflate failed: $DeflateError\n"; |
492 | |
493 | It returns an C<IO::Compress::Deflate> object on success and undef on failure. |
494 | The variable C<$DeflateError> will contain an error message on failure. |
495 | |
496 | If you are running Perl 5.005 or better the object, C<$z>, returned from |
497 | IO::Compress::Deflate can be used exactly like an L<IO::File|IO::File> filehandle. |
498 | This means that all normal output file operations can be carried out |
499 | with C<$z>. |
500 | For example, to write to a compressed file/buffer you can use either of |
501 | these forms |
502 | |
503 | $z->print("hello world\n"); |
504 | print $z "hello world\n"; |
505 | |
506 | The mandatory parameter C<$output> is used to control the destination |
507 | of the compressed data. This parameter can take one of these forms. |
508 | |
509 | =over 5 |
510 | |
511 | =item A filename |
512 | |
513 | If the C<$output> parameter is a simple scalar, it is assumed to be a |
514 | filename. This file will be opened for writing and the compressed data |
515 | will be written to it. |
516 | |
517 | =item A filehandle |
518 | |
519 | If the C<$output> parameter is a filehandle, the compressed data will be |
520 | written to it. |
521 | The string '-' can be used as an alias for standard output. |
522 | |
523 | |
524 | =item A scalar reference |
525 | |
526 | If C<$output> is a scalar reference, the compressed data will be stored |
527 | in C<$$output>. |
528 | |
529 | =back |
530 | |
531 | If the C<$output> parameter is any other type, C<IO::Compress::Deflate>::new will |
532 | return undef. |
533 | |
534 | =head2 Constructor Options |
535 | |
536 | C<OPTS> is any combination of the following options: |
537 | |
538 | =over 5 |
539 | |
540 | =item AutoClose =E<gt> 0|1 |
541 | |
542 | This option is only valid when the C<$output> parameter is a filehandle. If |
543 | specified, and the value is true, it will result in the C<$output> being |
544 | closed once either the C<close> method is called or the C<IO::Compress::Deflate> |
545 | object is destroyed. |
546 | |
547 | This parameter defaults to 0. |
548 | |
549 | =item Append =E<gt> 0|1 |
550 | |
551 | Opens C<$output> in append mode. |
552 | |
553 | The behaviour of this option is dependent on the type of C<$output>. |
554 | |
555 | =over 5 |
556 | |
557 | =item * A Buffer |
558 | |
559 | If C<$output> is a buffer and C<Append> is enabled, all compressed data |
560 | will be append to the end if C<$output>. Otherwise C<$output> will be |
561 | cleared before any data is written to it. |
562 | |
563 | =item * A Filename |
564 | |
565 | If C<$output> is a filename and C<Append> is enabled, the file will be |
566 | opened in append mode. Otherwise the contents of the file, if any, will be |
567 | truncated before any compressed data is written to it. |
568 | |
569 | =item * A Filehandle |
570 | |
571 | If C<$output> is a filehandle, the file pointer will be positioned to the |
572 | end of the file via a call to C<seek> before any compressed data is written |
573 | to it. Otherwise the file pointer will not be moved. |
574 | |
575 | =back |
576 | |
577 | This parameter defaults to 0. |
578 | |
579 | |
580 | |
581 | |
582 | |
cb7abd7f |
583 | =item Merge =E<gt> 0|1 |
25f0751f |
584 | |
585 | This option is used to compress input data and append it to an existing |
586 | compressed data stream in C<$output>. The end result is a single compressed |
587 | data stream stored in C<$output>. |
588 | |
589 | |
590 | |
591 | It is a fatal error to attempt to use this option when C<$output> is not an |
592 | RFC 1950 data stream. |
593 | |
594 | |
595 | |
596 | There are a number of other limitations with the C<Merge> option: |
597 | |
598 | =over 5 |
599 | |
600 | =item 1 |
601 | |
602 | This module needs to have been built with zlib 1.2.1 or better to work. A |
603 | fatal error will be thrown if C<Merge> is used with an older version of |
604 | zlib. |
605 | |
606 | =item 2 |
607 | |
608 | If C<$output> is a file or a filehandle, it must be seekable. |
609 | |
610 | =back |
611 | |
612 | |
613 | This parameter defaults to 0. |
614 | |
615 | |
616 | |
617 | =item -Level |
618 | |
619 | Defines the compression level used by zlib. The value should either be |
620 | a number between 0 and 9 (0 means no compression and 9 is maximum |
621 | compression), or one of the symbolic constants defined below. |
622 | |
623 | Z_NO_COMPRESSION |
624 | Z_BEST_SPEED |
625 | Z_BEST_COMPRESSION |
626 | Z_DEFAULT_COMPRESSION |
627 | |
628 | The default is Z_DEFAULT_COMPRESSION. |
629 | |
630 | Note, these constants are not imported by C<IO::Compress::Deflate> by default. |
631 | |
632 | use IO::Compress::Deflate qw(:strategy); |
633 | use IO::Compress::Deflate qw(:constants); |
634 | use IO::Compress::Deflate qw(:all); |
635 | |
636 | =item -Strategy |
637 | |
638 | Defines the strategy used to tune the compression. Use one of the symbolic |
639 | constants defined below. |
640 | |
641 | Z_FILTERED |
642 | Z_HUFFMAN_ONLY |
643 | Z_RLE |
644 | Z_FIXED |
645 | Z_DEFAULT_STRATEGY |
646 | |
647 | The default is Z_DEFAULT_STRATEGY. |
648 | |
649 | |
650 | |
651 | |
652 | |
653 | |
654 | =item -Strict =E<gt> 0|1 |
655 | |
656 | |
657 | |
658 | This is a placeholder option. |
659 | |
660 | |
661 | |
662 | =back |
663 | |
664 | =head2 Examples |
665 | |
666 | TODO |
667 | |
668 | =head1 Methods |
669 | |
670 | =head2 print |
671 | |
672 | Usage is |
673 | |
674 | $z->print($data) |
675 | print $z $data |
676 | |
677 | Compresses and outputs the contents of the C<$data> parameter. This |
678 | has the same behaviour as the C<print> built-in. |
679 | |
680 | Returns true if successful. |
681 | |
682 | =head2 printf |
683 | |
684 | Usage is |
685 | |
686 | $z->printf($format, $data) |
687 | printf $z $format, $data |
688 | |
689 | Compresses and outputs the contents of the C<$data> parameter. |
690 | |
691 | Returns true if successful. |
692 | |
693 | =head2 syswrite |
694 | |
695 | Usage is |
696 | |
697 | $z->syswrite $data |
698 | $z->syswrite $data, $length |
699 | $z->syswrite $data, $length, $offset |
700 | |
701 | Compresses and outputs the contents of the C<$data> parameter. |
702 | |
703 | Returns the number of uncompressed bytes written, or C<undef> if |
704 | unsuccessful. |
705 | |
706 | =head2 write |
707 | |
708 | Usage is |
709 | |
710 | $z->write $data |
711 | $z->write $data, $length |
712 | $z->write $data, $length, $offset |
713 | |
714 | Compresses and outputs the contents of the C<$data> parameter. |
715 | |
716 | Returns the number of uncompressed bytes written, or C<undef> if |
717 | unsuccessful. |
718 | |
719 | =head2 flush |
720 | |
721 | Usage is |
722 | |
723 | |
724 | $z->flush; |
725 | $z->flush($flush_type); |
726 | |
727 | |
728 | Flushes any pending compressed data to the output file/buffer. |
729 | |
730 | |
731 | This method takes an optional parameter, C<$flush_type>, that controls |
732 | how the flushing will be carried out. By default the C<$flush_type> |
733 | used is C<Z_FINISH>. Other valid values for C<$flush_type> are |
734 | C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is |
735 | strongly recommended that you only set the C<flush_type> parameter if |
736 | you fully understand the implications of what it does - overuse of C<flush> |
737 | can seriously degrade the level of compression achieved. See the C<zlib> |
738 | documentation for details. |
739 | |
740 | |
741 | Returns true on success. |
742 | |
743 | |
744 | =head2 tell |
745 | |
746 | Usage is |
747 | |
748 | $z->tell() |
749 | tell $z |
750 | |
751 | Returns the uncompressed file offset. |
752 | |
753 | =head2 eof |
754 | |
755 | Usage is |
756 | |
757 | $z->eof(); |
758 | eof($z); |
759 | |
760 | |
761 | |
762 | Returns true if the C<close> method has been called. |
763 | |
764 | |
765 | |
766 | =head2 seek |
767 | |
768 | $z->seek($position, $whence); |
769 | seek($z, $position, $whence); |
770 | |
771 | |
772 | |
773 | |
774 | Provides a sub-set of the C<seek> functionality, with the restriction |
775 | that it is only legal to seek forward in the output file/buffer. |
776 | It is a fatal error to attempt to seek backward. |
777 | |
778 | Empty parts of the file/buffer will have NULL (0x00) bytes written to them. |
779 | |
780 | |
781 | |
782 | The C<$whence> parameter takes one the usual values, namely SEEK_SET, |
783 | SEEK_CUR or SEEK_END. |
784 | |
785 | Returns 1 on success, 0 on failure. |
786 | |
787 | =head2 binmode |
788 | |
789 | Usage is |
790 | |
791 | $z->binmode |
792 | binmode $z ; |
793 | |
794 | This is a noop provided for completeness. |
795 | |
796 | =head2 opened |
797 | |
798 | $z->opened() |
799 | |
800 | Returns true if the object currently refers to a opened file/buffer. |
801 | |
802 | =head2 autoflush |
803 | |
804 | my $prev = $z->autoflush() |
805 | my $prev = $z->autoflush(EXPR) |
806 | |
807 | If the C<$z> object is associated with a file or a filehandle, this method |
808 | returns the current autoflush setting for the underlying filehandle. If |
809 | C<EXPR> is present, and is non-zero, it will enable flushing after every |
810 | write/print operation. |
811 | |
812 | If C<$z> is associated with a buffer, this method has no effect and always |
813 | returns C<undef>. |
814 | |
815 | B<Note> that the special variable C<$|> B<cannot> be used to set or |
816 | retrieve the autoflush setting. |
817 | |
818 | =head2 input_line_number |
819 | |
820 | $z->input_line_number() |
821 | $z->input_line_number(EXPR) |
822 | |
823 | |
824 | This method always returns C<undef> when compressing. |
825 | |
826 | |
827 | |
828 | =head2 fileno |
829 | |
830 | $z->fileno() |
831 | fileno($z) |
832 | |
833 | If the C<$z> object is associated with a file or a filehandle, this method |
834 | will return the underlying file descriptor. |
835 | |
836 | If the C<$z> object is is associated with a buffer, this method will |
837 | return undef. |
838 | |
839 | =head2 close |
840 | |
841 | $z->close() ; |
842 | close $z ; |
843 | |
844 | |
845 | |
846 | Flushes any pending compressed data and then closes the output file/buffer. |
847 | |
848 | |
849 | |
850 | For most versions of Perl this method will be automatically invoked if |
851 | the IO::Compress::Deflate object is destroyed (either explicitly or by the |
852 | variable with the reference to the object going out of scope). The |
853 | exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In |
854 | these cases, the C<close> method will be called automatically, but |
855 | not until global destruction of all live objects when the program is |
856 | terminating. |
857 | |
858 | Therefore, if you want your scripts to be able to run on all versions |
859 | of Perl, you should call C<close> explicitly and not rely on automatic |
860 | closing. |
861 | |
862 | Returns true on success, otherwise 0. |
863 | |
864 | If the C<AutoClose> option has been enabled when the IO::Compress::Deflate |
865 | object was created, and the object is associated with a file, the |
866 | underlying file will also be closed. |
867 | |
868 | |
869 | |
870 | |
871 | =head2 newStream([OPTS]) |
872 | |
873 | Usage is |
874 | |
875 | $z->newStream( [OPTS] ) |
876 | |
877 | Closes the current compressed data stream and starts a new one. |
878 | |
879 | OPTS consists of the following sub-set of the the options that are |
880 | available when creating the C<$z> object, |
881 | |
882 | =over 5 |
883 | |
884 | |
885 | |
886 | =item * Level |
887 | |
888 | |
889 | |
890 | =back |
891 | |
892 | |
893 | =head2 deflateParams |
894 | |
895 | Usage is |
896 | |
897 | $z->deflateParams |
898 | |
899 | TODO |
900 | |
901 | |
902 | =head1 Importing |
903 | |
904 | |
905 | A number of symbolic constants are required by some methods in |
906 | C<IO::Compress::Deflate>. None are imported by default. |
907 | |
908 | |
909 | |
910 | =over 5 |
911 | |
912 | =item :all |
913 | |
914 | |
915 | Imports C<deflate>, C<$DeflateError> and all symbolic |
916 | constants that can be used by C<IO::Compress::Deflate>. Same as doing this |
917 | |
918 | use IO::Compress::Deflate qw(deflate $DeflateError :constants) ; |
919 | |
920 | =item :constants |
921 | |
922 | Import all symbolic constants. Same as doing this |
923 | |
2b4e0969 |
924 | |
25f0751f |
925 | use IO::Compress::Deflate qw(:flush :level :strategy) ; |
926 | |
2b4e0969 |
927 | |
25f0751f |
928 | =item :flush |
929 | |
930 | These symbolic constants are used by the C<flush> method. |
931 | |
932 | Z_NO_FLUSH |
933 | Z_PARTIAL_FLUSH |
934 | Z_SYNC_FLUSH |
935 | Z_FULL_FLUSH |
936 | Z_FINISH |
937 | Z_BLOCK |
938 | |
939 | =item :level |
940 | |
941 | These symbolic constants are used by the C<Level> option in the constructor. |
942 | |
943 | Z_NO_COMPRESSION |
944 | Z_BEST_SPEED |
945 | Z_BEST_COMPRESSION |
946 | Z_DEFAULT_COMPRESSION |
947 | |
948 | |
949 | =item :strategy |
950 | |
951 | These symbolic constants are used by the C<Strategy> option in the constructor. |
952 | |
953 | Z_FILTERED |
954 | Z_HUFFMAN_ONLY |
955 | Z_RLE |
956 | Z_FIXED |
957 | Z_DEFAULT_STRATEGY |
2b4e0969 |
958 | |
959 | |
25f0751f |
960 | |
961 | |
962 | =back |
963 | |
964 | For |
965 | |
966 | =head1 EXAMPLES |
967 | |
968 | TODO |
969 | |
970 | |
971 | |
972 | |
973 | |
974 | |
975 | =head1 SEE ALSO |
976 | |
977 | 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> |
978 | |
979 | L<Compress::Zlib::FAQ|Compress::Zlib::FAQ> |
980 | |
981 | L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>, |
982 | L<Archive::Tar|Archive::Tar>, |
983 | L<IO::Zlib|IO::Zlib> |
984 | |
985 | |
986 | For RFC 1950, 1951 and 1952 see |
987 | F<http://www.faqs.org/rfcs/rfc1950.html>, |
988 | F<http://www.faqs.org/rfcs/rfc1951.html> and |
989 | F<http://www.faqs.org/rfcs/rfc1952.html> |
990 | |
991 | The I<zlib> compression library was written by Jean-loup Gailly |
992 | F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>. |
993 | |
994 | The primary site for the I<zlib> compression library is |
995 | F<http://www.zlib.org>. |
996 | |
997 | The primary site for gzip is F<http://www.gzip.org>. |
998 | |
999 | |
1000 | |
1001 | |
25f0751f |
1002 | =head1 AUTHOR |
1003 | |
cb7abd7f |
1004 | This module was written by Paul Marquess, F<pmqs@cpan.org>. |
25f0751f |
1005 | |
1006 | |
1007 | |
1008 | =head1 MODIFICATION HISTORY |
1009 | |
1010 | See the Changes file. |
1011 | |
1012 | =head1 COPYRIGHT AND LICENSE |
25f0751f |
1013 | |
1014 | Copyright (c) 2005-2006 Paul Marquess. All rights reserved. |
1015 | |
1016 | This program is free software; you can redistribute it and/or |
1017 | modify it under the same terms as Perl itself. |
1018 | |
1019 | |