Commit | Line | Data |
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1 | |
2 | package Compress::Zlib; |
3 | |
4 | require 5.004 ; |
5 | require Exporter; |
f4c6fd49 |
6 | use AutoLoader; |
7 | use Carp ; |
8 | use IO::Handle ; |
642e522c |
9 | use Scalar::Util qw(dualvar); |
10 | |
11 | use Compress::Zlib::Common; |
12 | use Compress::Zlib::ParseParameters; |
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13 | |
14 | use strict ; |
8aa25532 |
15 | use warnings ; |
642e522c |
16 | use bytes ; |
17 | our ($VERSION, $XS_VERSION, @ISA, @EXPORT, $AUTOLOAD); |
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18 | |
642e522c |
19 | $VERSION = '2.000_05'; |
20 | $XS_VERSION = $VERSION; |
21 | $VERSION = eval $VERSION; |
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22 | |
06edba15 |
23 | @ISA = qw(Exporter); |
f4c6fd49 |
24 | # Items to export into callers namespace by default. Note: do not export |
25 | # names by default without a very good reason. Use EXPORT_OK instead. |
26 | # Do not simply export all your public functions/methods/constants. |
27 | @EXPORT = qw( |
642e522c |
28 | deflateInit inflateInit |
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29 | |
642e522c |
30 | compress uncompress |
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31 | |
642e522c |
32 | gzopen $gzerrno |
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33 | |
642e522c |
34 | adler32 crc32 |
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35 | |
642e522c |
36 | ZLIB_VERSION |
37 | ZLIB_VERNUM |
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38 | |
642e522c |
39 | DEF_WBITS |
40 | OS_CODE |
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41 | |
42 | MAX_MEM_LEVEL |
642e522c |
43 | MAX_WBITS |
44 | |
45 | Z_ASCII |
46 | Z_BEST_COMPRESSION |
47 | Z_BEST_SPEED |
48 | Z_BINARY |
49 | Z_BLOCK |
50 | Z_BUF_ERROR |
51 | Z_DATA_ERROR |
52 | Z_DEFAULT_COMPRESSION |
53 | Z_DEFAULT_STRATEGY |
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54 | Z_DEFLATED |
642e522c |
55 | Z_ERRNO |
56 | Z_FILTERED |
57 | Z_FIXED |
58 | Z_FINISH |
59 | Z_FULL_FLUSH |
60 | Z_HUFFMAN_ONLY |
61 | Z_MEM_ERROR |
62 | Z_NEED_DICT |
63 | Z_NO_COMPRESSION |
64 | Z_NO_FLUSH |
65 | Z_NULL |
66 | Z_OK |
67 | Z_PARTIAL_FLUSH |
68 | Z_RLE |
69 | Z_STREAM_END |
70 | Z_STREAM_ERROR |
71 | Z_SYNC_FLUSH |
72 | Z_UNKNOWN |
73 | Z_VERSION_ERROR |
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74 | ); |
75 | |
f4c6fd49 |
76 | sub AUTOLOAD { |
77 | my($constname); |
78 | ($constname = $AUTOLOAD) =~ s/.*:://; |
79 | my ($error, $val) = constant($constname); |
80 | Carp::croak $error if $error; |
81 | no strict 'refs'; |
82 | *{$AUTOLOAD} = sub { $val }; |
83 | goto &{$AUTOLOAD}; |
84 | } |
85 | |
642e522c |
86 | use constant FLAG_APPEND => 1 ; |
87 | use constant FLAG_CRC => 2 ; |
88 | use constant FLAG_ADLER => 4 ; |
89 | use constant FLAG_CONSUME_INPUT => 8 ; |
90 | |
06edba15 |
91 | eval { |
92 | require XSLoader; |
642e522c |
93 | XSLoader::load('Compress::Zlib', $XS_VERSION); |
94 | 1; |
95 | } |
96 | or do { |
06edba15 |
97 | require DynaLoader; |
98 | local @ISA = qw(DynaLoader); |
642e522c |
99 | bootstrap Compress::Zlib $XS_VERSION ; |
100 | }; |
101 | |
f4c6fd49 |
102 | # Preloaded methods go here. |
103 | |
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104 | require IO::Compress::Gzip; |
105 | require IO::Uncompress::Gunzip; |
106 | |
107 | our (@my_z_errmsg); |
108 | |
109 | @my_z_errmsg = ( |
110 | "need dictionary", # Z_NEED_DICT 2 |
111 | "stream end", # Z_STREAM_END 1 |
112 | "", # Z_OK 0 |
113 | "file error", # Z_ERRNO (-1) |
114 | "stream error", # Z_STREAM_ERROR (-2) |
115 | "data error", # Z_DATA_ERROR (-3) |
116 | "insufficient memory", # Z_MEM_ERROR (-4) |
117 | "buffer error", # Z_BUF_ERROR (-5) |
118 | "incompatible version",# Z_VERSION_ERROR(-6) |
119 | ); |
120 | |
121 | |
122 | sub _set_gzerr |
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123 | { |
642e522c |
124 | my $value = shift ; |
f4c6fd49 |
125 | |
642e522c |
126 | if ($value == 0) { |
127 | $Compress::Zlib::gzerrno = 0 ; |
128 | } |
129 | elsif ($value == Z_ERRNO() || $value > 2) { |
130 | $Compress::Zlib::gzerrno = $! ; |
131 | } |
132 | else { |
133 | $Compress::Zlib::gzerrno = dualvar($value+0, $my_z_errmsg[2 - $value]); |
134 | } |
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135 | |
642e522c |
136 | return $value ; |
f4c6fd49 |
137 | } |
138 | |
642e522c |
139 | sub _save_gzerr |
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140 | { |
642e522c |
141 | my $gz = shift ; |
142 | my $test_eof = shift ; |
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143 | |
642e522c |
144 | my $value = $gz->errorNo() || 0 ; |
145 | |
146 | if ($test_eof) { |
147 | #my $gz = $self->[0] ; |
148 | # gzread uses Z_STREAM_END to denote a successful end |
149 | $value = Z_STREAM_END() if $gz->eof() && $value == 0 ; |
150 | } |
151 | |
152 | _set_gzerr($value) ; |
f4c6fd49 |
153 | } |
154 | |
155 | sub gzopen($$) |
156 | { |
157 | my ($file, $mode) = @_ ; |
642e522c |
158 | |
159 | my $gz ; |
160 | my %defOpts = (Level => Z_DEFAULT_COMPRESSION(), |
161 | Strategy => Z_DEFAULT_STRATEGY(), |
162 | ); |
163 | |
164 | my $writing ; |
165 | $writing = ! ($mode =~ /r/i) ; |
166 | $writing = ($mode =~ /[wa]/i) ; |
167 | |
168 | $defOpts{Level} = $1 if $mode =~ /(\d)/; |
169 | $defOpts{Strategy} = Z_FILTERED() if $mode =~ /f/i; |
170 | $defOpts{Strategy} = Z_HUFFMAN_ONLY() if $mode =~ /h/i; |
171 | |
172 | my $infDef = $writing ? 'deflate' : 'inflate'; |
173 | my @params = () ; |
174 | |
175 | croak "gzopen: file parameter is not a filehandle or filename" |
176 | unless isaFilehandle $file || isaFilename $file ; |
177 | |
178 | return undef unless $mode =~ /[rwa]/i ; |
179 | |
180 | _set_gzerr(0) ; |
181 | |
182 | if ($writing) { |
183 | $gz = new IO::Compress::Gzip($file, Minimal => 1, AutoClose => 1, %defOpts) |
184 | or $Compress::Zlib::gzerrno = $IO::Compress::Gzip::GzipError; |
f4c6fd49 |
185 | } |
186 | else { |
642e522c |
187 | $gz = new IO::Uncompress::Gunzip($file, Append => 0, AutoClose => 1, Strict => 0) |
188 | or $Compress::Zlib::gzerrno = $IO::Uncompress::Gunzip::GunzipError; |
f4c6fd49 |
189 | } |
642e522c |
190 | |
191 | return undef |
192 | if ! defined $gz ; |
193 | |
194 | bless [$gz, $infDef], 'Compress::Zlib::gzFile'; |
195 | } |
196 | |
197 | sub Compress::Zlib::gzFile::gzread |
198 | { |
199 | my $self = shift ; |
200 | |
201 | return _set_gzerr(Z_STREAM_ERROR()) |
202 | if $self->[1] ne 'inflate'; |
203 | |
204 | return 0 if $self->gzeof(); |
205 | |
206 | my $gz = $self->[0] ; |
207 | my $status = $gz->read($_[0], defined $_[1] ? $_[1] : 4096) ; |
208 | $_[0] = "" if ! defined $_[0] ; |
209 | _save_gzerr($gz, 1); |
210 | return $status ; |
f4c6fd49 |
211 | } |
212 | |
642e522c |
213 | sub Compress::Zlib::gzFile::gzreadline |
f4c6fd49 |
214 | { |
642e522c |
215 | my $self = shift ; |
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216 | |
642e522c |
217 | my $gz = $self->[0] ; |
218 | $_[0] = $gz->getline() ; |
219 | _save_gzerr($gz, 1); |
220 | return defined $_[0] ? length $_[0] : 0 ; |
221 | } |
f4c6fd49 |
222 | |
642e522c |
223 | sub Compress::Zlib::gzFile::gzwrite |
224 | { |
225 | my $self = shift ; |
226 | my $gz = $self->[0] ; |
f4c6fd49 |
227 | |
642e522c |
228 | return _set_gzerr(Z_STREAM_ERROR()) |
229 | if $self->[1] ne 'deflate'; |
f4c6fd49 |
230 | |
642e522c |
231 | my $status = $gz->write($_[0]) ; |
232 | _save_gzerr($gz); |
233 | return $status ; |
234 | } |
f4c6fd49 |
235 | |
642e522c |
236 | sub Compress::Zlib::gzFile::gztell |
237 | { |
238 | my $self = shift ; |
239 | my $gz = $self->[0] ; |
240 | my $status = $gz->tell() ; |
241 | _save_gzerr($gz); |
242 | return $status ; |
243 | } |
244 | |
245 | sub Compress::Zlib::gzFile::gzseek |
246 | { |
247 | my $self = shift ; |
248 | my $offset = shift ; |
249 | my $whence = shift ; |
250 | |
251 | my $gz = $self->[0] ; |
252 | my $status ; |
253 | eval { $status = $gz->seek($offset, $whence) ; }; |
254 | if ($@) |
255 | { |
256 | my $error = $@; |
257 | $error =~ s/^.*: /gzseek: /; |
258 | $error =~ s/ at .* line \d+\s*$//; |
259 | croak $error; |
f4c6fd49 |
260 | } |
642e522c |
261 | _save_gzerr($gz); |
262 | return $status ; |
263 | } |
264 | |
265 | sub Compress::Zlib::gzFile::gzflush |
266 | { |
267 | my $self = shift ; |
268 | my $f = shift ; |
f4c6fd49 |
269 | |
642e522c |
270 | my $gz = $self->[0] ; |
271 | my $status = $gz->flush($f) ; |
272 | _save_gzerr($gz); |
273 | return $status ; |
f4c6fd49 |
274 | } |
275 | |
642e522c |
276 | sub Compress::Zlib::gzFile::gzclose |
277 | { |
278 | my $self = shift ; |
279 | my $gz = $self->[0] ; |
f4c6fd49 |
280 | |
642e522c |
281 | my $status = $gz->close() ; |
282 | _save_gzerr($gz); |
283 | return ! $status ; |
284 | } |
f4c6fd49 |
285 | |
642e522c |
286 | sub Compress::Zlib::gzFile::gzeof |
287 | { |
288 | my $self = shift ; |
289 | my $gz = $self->[0] ; |
290 | |
291 | return 0 |
292 | if $self->[1] ne 'inflate'; |
293 | |
294 | my $status = $gz->eof() ; |
295 | _save_gzerr($gz); |
296 | return $status ; |
297 | } |
298 | |
299 | sub Compress::Zlib::gzFile::gzsetparams |
300 | { |
301 | my $self = shift ; |
302 | croak "Usage: Compress::Zlib::gzFile::gzsetparams(file, level, strategy)" |
303 | unless @_ eq 2 ; |
304 | |
305 | my $gz = $self->[0] ; |
306 | my $level = shift ; |
307 | my $strategy = shift; |
308 | |
309 | return _set_gzerr(Z_STREAM_ERROR()) |
310 | if $self->[1] ne 'deflate'; |
311 | |
312 | my $status = *$gz->{Deflate}->deflateParams(-Level => $level, |
313 | -Strategy => $strategy); |
314 | _save_gzerr($gz); |
315 | return $status ; |
316 | } |
317 | |
318 | sub Compress::Zlib::gzFile::gzerror |
f4c6fd49 |
319 | { |
642e522c |
320 | my $self = shift ; |
321 | my $gz = $self->[0] ; |
322 | |
323 | return $Compress::Zlib::gzerrno ; |
f4c6fd49 |
324 | } |
325 | |
642e522c |
326 | sub Compress::Zlib::Deflate::new |
327 | { |
328 | my $pkg = shift ; |
329 | my ($got) = ParseParameters(0, |
330 | { |
331 | 'AppendOutput' => [Parse_boolean, 0], |
332 | 'CRC32' => [Parse_boolean, 0], |
333 | 'ADLER32' => [Parse_boolean, 0], |
334 | 'Bufsize' => [Parse_unsigned, 4096], |
335 | |
336 | 'Level' => [Parse_signed, Z_DEFAULT_COMPRESSION()], |
337 | 'Method' => [Parse_unsigned, Z_DEFLATED()], |
338 | 'WindowBits' => [Parse_signed, MAX_WBITS()], |
339 | 'MemLevel' => [Parse_unsigned, MAX_MEM_LEVEL()], |
340 | 'Strategy' => [Parse_unsigned, Z_DEFAULT_STRATEGY()], |
341 | 'Dictionary' => [Parse_any, ""], |
342 | }, @_) ; |
343 | |
344 | |
345 | croak "Compress::Zlib::Deflate::new: Bufsize must be >= 1, you specified " . |
346 | $got->value('Bufsize') |
347 | unless $got->value('Bufsize') >= 1; |
348 | |
349 | my $flags = 0 ; |
350 | $flags |= FLAG_APPEND if $got->value('AppendOutput') ; |
351 | $flags |= FLAG_CRC if $got->value('CRC32') ; |
352 | $flags |= FLAG_ADLER if $got->value('ADLER32') ; |
353 | |
354 | _deflateInit($flags, |
355 | $got->value('Level'), |
356 | $got->value('Method'), |
357 | $got->value('WindowBits'), |
358 | $got->value('MemLevel'), |
359 | $got->value('Strategy'), |
360 | $got->value('Bufsize'), |
361 | $got->value('Dictionary')) ; |
362 | |
363 | } |
364 | |
365 | sub Compress::Zlib::Inflate::new |
366 | { |
367 | my $pkg = shift ; |
368 | my ($got) = ParseParameters(0, |
369 | { |
370 | 'AppendOutput' => [Parse_boolean, 0], |
371 | 'CRC32' => [Parse_boolean, 0], |
372 | 'ADLER32' => [Parse_boolean, 0], |
373 | 'ConsumeInput' => [Parse_boolean, 1], |
374 | 'Bufsize' => [Parse_unsigned, 4096], |
375 | |
376 | 'WindowBits' => [Parse_signed, MAX_WBITS()], |
377 | 'Dictionary' => [Parse_any, ""], |
378 | }, @_) ; |
379 | |
380 | |
381 | croak "Compress::Zlib::Inflate::new: Bufsize must be >= 1, you specified " . |
382 | $got->value('Bufsize') |
383 | unless $got->value('Bufsize') >= 1; |
384 | |
385 | my $flags = 0 ; |
386 | $flags |= FLAG_APPEND if $got->value('AppendOutput') ; |
387 | $flags |= FLAG_CRC if $got->value('CRC32') ; |
388 | $flags |= FLAG_ADLER if $got->value('ADLER32') ; |
389 | $flags |= FLAG_CONSUME_INPUT if $got->value('ConsumeInput') ; |
390 | |
391 | _inflateInit($flags, $got->value('WindowBits'), $got->value('Bufsize'), |
392 | $got->value('Dictionary')) ; |
393 | } |
394 | |
395 | sub Compress::Zlib::InflateScan::new |
396 | { |
397 | my $pkg = shift ; |
398 | my ($got) = ParseParameters(0, |
399 | { |
400 | 'CRC32' => [Parse_boolean, 0], |
401 | 'ADLER32' => [Parse_boolean, 0], |
402 | 'Bufsize' => [Parse_unsigned, 4096], |
403 | |
404 | 'WindowBits' => [Parse_signed, -MAX_WBITS()], |
405 | 'Dictionary' => [Parse_any, ""], |
406 | }, @_) ; |
407 | |
408 | |
409 | croak "Compress::Zlib::InflateScan::new: Bufsize must be >= 1, you specified " . |
410 | $got->value('Bufsize') |
411 | unless $got->value('Bufsize') >= 1; |
412 | |
413 | my $flags = 0 ; |
414 | #$flags |= FLAG_APPEND if $got->value('AppendOutput') ; |
415 | $flags |= FLAG_CRC if $got->value('CRC32') ; |
416 | $flags |= FLAG_ADLER if $got->value('ADLER32') ; |
417 | #$flags |= FLAG_CONSUME_INPUT if $got->value('ConsumeInput') ; |
418 | |
419 | _inflateScanInit($flags, $got->value('WindowBits'), $got->value('Bufsize'), |
420 | '') ; |
421 | } |
422 | |
423 | sub Compress::Zlib::inflateScanStream::createDeflateStream |
f4c6fd49 |
424 | { |
642e522c |
425 | my $pkg = shift ; |
426 | my ($got) = ParseParameters(0, |
427 | { |
428 | 'AppendOutput' => [Parse_boolean, 0], |
429 | 'CRC32' => [Parse_boolean, 0], |
430 | 'ADLER32' => [Parse_boolean, 0], |
431 | 'Bufsize' => [Parse_unsigned, 4096], |
f4c6fd49 |
432 | |
642e522c |
433 | 'Level' => [Parse_signed, Z_DEFAULT_COMPRESSION()], |
434 | 'Method' => [Parse_unsigned, Z_DEFLATED()], |
435 | 'WindowBits' => [Parse_signed, - MAX_WBITS()], |
436 | 'MemLevel' => [Parse_unsigned, MAX_MEM_LEVEL()], |
437 | 'Strategy' => [Parse_unsigned, Z_DEFAULT_STRATEGY()], |
438 | }, @_) ; |
439 | |
440 | croak "Compress::Zlib::InflateScan::createDeflateStream: Bufsize must be >= 1, you specified " . |
441 | $got->value('Bufsize') |
442 | unless $got->value('Bufsize') >= 1; |
443 | |
444 | my $flags = 0 ; |
445 | $flags |= FLAG_APPEND if $got->value('AppendOutput') ; |
446 | $flags |= FLAG_CRC if $got->value('CRC32') ; |
447 | $flags |= FLAG_ADLER if $got->value('ADLER32') ; |
448 | |
449 | $pkg->_createDeflateStream($flags, |
450 | $got->value('Level'), |
451 | $got->value('Method'), |
452 | $got->value('WindowBits'), |
453 | $got->value('MemLevel'), |
454 | $got->value('Strategy'), |
455 | $got->value('Bufsize'), |
456 | ) ; |
457 | |
f4c6fd49 |
458 | } |
459 | |
642e522c |
460 | |
f4c6fd49 |
461 | sub Compress::Zlib::deflateStream::deflateParams |
462 | { |
463 | my $self = shift ; |
642e522c |
464 | my ($got) = ParseParameters(0, { |
465 | 'Level' => [Parse_signed, undef], |
466 | 'Strategy' => [Parse_unsigned, undef], |
467 | 'Bufsize' => [Parse_unsigned, undef], |
468 | }, |
469 | @_) ; |
470 | |
471 | croak "Compress::Zlib::deflateParams needs Level and/or Strategy" |
472 | unless $got->parsed('Level') + $got->parsed('Strategy') + |
473 | $got->parsed('Bufsize'); |
474 | |
475 | croak "Compress::Zlib::Inflate::deflateParams: Bufsize must be >= 1, you specified " . |
476 | $got->value('Bufsize') |
477 | if $got->parsed('Bufsize') && $got->value('Bufsize') <= 1; |
f4c6fd49 |
478 | |
479 | my $flags = 0; |
642e522c |
480 | $flags |= 1 if $got->parsed('Level') ; |
481 | $flags |= 2 if $got->parsed('Strategy') ; |
482 | $flags |= 4 if $got->parsed('Bufsize') ; |
483 | |
484 | $self->_deflateParams($flags, $got->value('Level'), |
485 | $got->value('Strategy'), $got->value('Bufsize')); |
486 | |
f4c6fd49 |
487 | } |
488 | |
489 | sub compress($;$) |
490 | { |
642e522c |
491 | my ($x, $output, $err, $in) =('', '', '', '') ; |
f4c6fd49 |
492 | |
493 | if (ref $_[0] ) { |
494 | $in = $_[0] ; |
642e522c |
495 | croak "not a scalar reference" unless ref $in eq 'SCALAR' ; |
f4c6fd49 |
496 | } |
497 | else { |
498 | $in = \$_[0] ; |
499 | } |
500 | |
501 | my $level = (@_ == 2 ? $_[1] : Z_DEFAULT_COMPRESSION() ); |
502 | |
642e522c |
503 | $x = new Compress::Zlib::Deflate -AppendOutput => 1, -Level => $level |
504 | or return undef ; |
f4c6fd49 |
505 | |
642e522c |
506 | $err = $x->deflate($in, $output) ; |
507 | return undef unless $err == Z_OK() ; |
f4c6fd49 |
508 | |
642e522c |
509 | $err = $x->flush($output) ; |
510 | return undef unless $err == Z_OK() ; |
f4c6fd49 |
511 | |
642e522c |
512 | return $output ; |
f4c6fd49 |
513 | |
f4c6fd49 |
514 | } |
515 | |
f4c6fd49 |
516 | sub uncompress($) |
517 | { |
642e522c |
518 | my ($x, $output, $err, $in) =('', '', '', '') ; |
f4c6fd49 |
519 | |
520 | if (ref $_[0] ) { |
521 | $in = $_[0] ; |
642e522c |
522 | croak "not a scalar reference" unless ref $in eq 'SCALAR' ; |
f4c6fd49 |
523 | } |
524 | else { |
525 | $in = \$_[0] ; |
526 | } |
527 | |
642e522c |
528 | $x = new Compress::Zlib::Inflate -ConsumeInput => 0 or return undef ; |
f4c6fd49 |
529 | |
642e522c |
530 | $err = $x->inflate($in, $output) ; |
531 | return undef unless $err == Z_STREAM_END() ; |
f4c6fd49 |
532 | |
642e522c |
533 | return $output ; |
534 | } |
535 | |
536 | |
537 | ### This stuff is for backward compat. with Compress::Zlib 1.x |
538 | |
f4c6fd49 |
539 | |
642e522c |
540 | sub deflateInit(@) |
541 | { |
542 | my ($got) = ParseParameters(0, |
543 | { |
544 | 'Bufsize' => [Parse_unsigned, 4096], |
545 | 'Level' => [Parse_signed, Z_DEFAULT_COMPRESSION()], |
546 | 'Method' => [Parse_unsigned, Z_DEFLATED()], |
547 | 'WindowBits' => [Parse_signed, MAX_WBITS()], |
548 | 'MemLevel' => [Parse_unsigned, MAX_MEM_LEVEL()], |
549 | 'Strategy' => [Parse_unsigned, Z_DEFAULT_STRATEGY()], |
550 | 'Dictionary' => [Parse_any, ""], |
551 | }, @_ ) ; |
552 | |
553 | croak "Compress::Zlib::deflateInit: Bufsize must be >= 1, you specified " . |
554 | $got->value('Bufsize') |
555 | unless $got->value('Bufsize') >= 1; |
556 | |
557 | my (%obj) = () ; |
558 | |
559 | my $status = 0 ; |
560 | ($obj{def}, $status) = |
561 | _deflateInit(0, |
562 | $got->value('Level'), |
563 | $got->value('Method'), |
564 | $got->value('WindowBits'), |
565 | $got->value('MemLevel'), |
566 | $got->value('Strategy'), |
567 | $got->value('Bufsize'), |
568 | $got->value('Dictionary')) ; |
569 | |
570 | my $x = ($status == Z_OK() ? bless \%obj, "Zlib::OldDeflate" : undef) ; |
571 | return wantarray ? ($x, $status) : $x ; |
f4c6fd49 |
572 | } |
642e522c |
573 | |
574 | sub inflateInit(@) |
575 | { |
576 | my ($got) = ParseParameters(0, |
577 | { |
578 | 'Bufsize' => [Parse_unsigned, 4096], |
579 | 'WindowBits' => [Parse_signed, MAX_WBITS()], |
580 | 'Dictionary' => [Parse_any, ""], |
581 | }, @_) ; |
f4c6fd49 |
582 | |
583 | |
642e522c |
584 | croak "Compress::Zlib::inflateInit: Bufsize must be >= 1, you specified " . |
585 | $got->value('Bufsize') |
586 | unless $got->value('Bufsize') >= 1; |
f4c6fd49 |
587 | |
642e522c |
588 | my $status = 0 ; |
589 | my (%obj) = () ; |
590 | ($obj{def}, $status) = _inflateInit(FLAG_CONSUME_INPUT, |
591 | $got->value('WindowBits'), |
592 | $got->value('Bufsize'), |
593 | $got->value('Dictionary')) ; |
594 | |
595 | my $x = ($status == Z_OK() ? bless \%obj, "Zlib::OldInflate" : undef) ; |
596 | |
597 | wantarray ? ($x, $status) : $x ; |
598 | } |
599 | |
600 | package Zlib::OldDeflate ; |
601 | |
602 | sub deflate |
603 | { |
604 | my $self = shift ; |
605 | my $output ; |
606 | #my (@rest) = @_ ; |
607 | |
608 | my $status = $self->{def}->deflate($_[0], $output) ; |
609 | |
610 | wantarray ? ($output, $status) : $output ; |
611 | } |
612 | |
613 | sub flush |
614 | { |
615 | my $self = shift ; |
616 | my $output ; |
617 | my $flag = shift || Compress::Zlib::Z_FINISH(); |
618 | my $status = $self->{def}->flush($output, $flag) ; |
619 | |
620 | wantarray ? ($output, $status) : $output ; |
621 | } |
622 | |
623 | sub deflateParams |
624 | { |
625 | my $self = shift ; |
626 | $self->{def}->deflateParams(@_) ; |
627 | } |
628 | |
629 | sub msg |
630 | { |
631 | my $self = shift ; |
632 | $self->{def}->msg() ; |
633 | } |
634 | |
635 | sub total_in |
636 | { |
637 | my $self = shift ; |
638 | $self->{def}->total_in() ; |
639 | } |
640 | |
641 | sub total_out |
642 | { |
643 | my $self = shift ; |
644 | $self->{def}->total_out() ; |
645 | } |
646 | |
647 | sub dict_adler |
648 | { |
649 | my $self = shift ; |
650 | $self->{def}->dict_adler() ; |
651 | } |
652 | |
653 | sub get_Level |
654 | { |
655 | my $self = shift ; |
656 | $self->{def}->get_Level() ; |
657 | } |
658 | |
659 | sub get_Strategy |
660 | { |
661 | my $self = shift ; |
662 | $self->{def}->get_Strategy() ; |
663 | } |
664 | |
665 | #sub DispStream |
666 | #{ |
667 | # my $self = shift ; |
668 | # $self->{def}->DispStream($_[0]) ; |
669 | #} |
670 | |
671 | package Zlib::OldInflate ; |
672 | |
673 | sub inflate |
674 | { |
675 | my $self = shift ; |
676 | my $output ; |
677 | my $status = $self->{def}->inflate($_[0], $output) ; |
678 | wantarray ? ($output, $status) : $output ; |
679 | } |
680 | |
681 | sub inflateSync |
682 | { |
683 | my $self = shift ; |
684 | $self->{def}->inflateSync($_[0]) ; |
685 | } |
686 | |
687 | sub msg |
688 | { |
689 | my $self = shift ; |
690 | $self->{def}->msg() ; |
691 | } |
692 | |
693 | sub total_in |
694 | { |
695 | my $self = shift ; |
696 | $self->{def}->total_in() ; |
697 | } |
698 | |
699 | sub total_out |
700 | { |
701 | my $self = shift ; |
702 | $self->{def}->total_out() ; |
703 | } |
704 | |
705 | sub dict_adler |
706 | { |
707 | my $self = shift ; |
708 | $self->{def}->dict_adler() ; |
709 | } |
710 | |
711 | #sub DispStream |
712 | #{ |
713 | # my $self = shift ; |
714 | # $self->{def}->DispStream($_[0]) ; |
715 | #} |
716 | |
717 | package Compress::Zlib ; |
718 | |
719 | use Compress::Gzip::Constants; |
f4c6fd49 |
720 | |
f4c6fd49 |
721 | sub memGzip($) |
722 | { |
642e522c |
723 | my $x = new Compress::Zlib::Deflate( |
724 | -AppendOutput => 1, |
725 | -CRC32 => 1, |
726 | -ADLER32 => 0, |
f4c6fd49 |
727 | -Level => Z_BEST_COMPRESSION(), |
642e522c |
728 | -WindowBits => - MAX_WBITS(), |
f4c6fd49 |
729 | ) |
730 | or return undef ; |
731 | |
732 | # write a minimal gzip header |
642e522c |
733 | my $output = GZIP_MINIMUM_HEADER ; |
f4c6fd49 |
734 | |
735 | # if the deflation buffer isn't a reference, make it one |
736 | my $string = (ref $_[0] ? $_[0] : \$_[0]) ; |
737 | |
642e522c |
738 | my $status = $x->deflate($string, \$output) ; |
f4c6fd49 |
739 | $status == Z_OK() |
740 | or return undef ; |
741 | |
642e522c |
742 | $status = $x->flush(\$output) ; |
f4c6fd49 |
743 | $status == Z_OK() |
744 | or return undef ; |
745 | |
642e522c |
746 | return $output . pack("V V", $x->crc32(), $x->total_in()) ; |
f4c6fd49 |
747 | |
f4c6fd49 |
748 | } |
749 | |
642e522c |
750 | |
f4c6fd49 |
751 | sub _removeGzipHeader($) |
752 | { |
753 | my $string = shift ; |
754 | |
755 | return Z_DATA_ERROR() |
642e522c |
756 | if length($$string) < GZIP_MIN_HEADER_SIZE ; |
f4c6fd49 |
757 | |
758 | my ($magic1, $magic2, $method, $flags, $time, $xflags, $oscode) = |
759 | unpack ('CCCCVCC', $$string); |
760 | |
761 | return Z_DATA_ERROR() |
642e522c |
762 | unless $magic1 == GZIP_ID1 and $magic2 == GZIP_ID2 and |
763 | $method == Z_DEFLATED() and !($flags & GZIP_FLG_RESERVED) ; |
764 | substr($$string, 0, GZIP_MIN_HEADER_SIZE) = '' ; |
f4c6fd49 |
765 | |
766 | # skip extra field |
642e522c |
767 | if ($flags & GZIP_FLG_FEXTRA) |
f4c6fd49 |
768 | { |
769 | return Z_DATA_ERROR() |
642e522c |
770 | if length($$string) < GZIP_FEXTRA_HEADER_SIZE ; |
f4c6fd49 |
771 | |
772 | my ($extra_len) = unpack ('v', $$string); |
642e522c |
773 | $extra_len += GZIP_FEXTRA_HEADER_SIZE; |
f4c6fd49 |
774 | return Z_DATA_ERROR() |
775 | if length($$string) < $extra_len ; |
776 | |
777 | substr($$string, 0, $extra_len) = ''; |
778 | } |
779 | |
780 | # skip orig name |
642e522c |
781 | if ($flags & GZIP_FLG_FNAME) |
f4c6fd49 |
782 | { |
642e522c |
783 | my $name_end = index ($$string, GZIP_NULL_BYTE); |
f4c6fd49 |
784 | return Z_DATA_ERROR() |
785 | if $name_end == -1 ; |
786 | substr($$string, 0, $name_end + 1) = ''; |
787 | } |
788 | |
789 | # skip comment |
642e522c |
790 | if ($flags & GZIP_FLG_FCOMMENT) |
f4c6fd49 |
791 | { |
642e522c |
792 | my $comment_end = index ($$string, GZIP_NULL_BYTE); |
f4c6fd49 |
793 | return Z_DATA_ERROR() |
794 | if $comment_end == -1 ; |
795 | substr($$string, 0, $comment_end + 1) = ''; |
796 | } |
797 | |
798 | # skip header crc |
642e522c |
799 | if ($flags & GZIP_FLG_FHCRC) |
f4c6fd49 |
800 | { |
801 | return Z_DATA_ERROR() |
642e522c |
802 | if length ($$string) < GZIP_FHCRC_SIZE ; |
803 | substr($$string, 0, GZIP_FHCRC_SIZE) = ''; |
f4c6fd49 |
804 | } |
805 | |
806 | return Z_OK(); |
807 | } |
808 | |
809 | |
810 | sub memGunzip($) |
811 | { |
812 | # if the buffer isn't a reference, make it one |
813 | my $string = (ref $_[0] ? $_[0] : \$_[0]); |
814 | |
815 | _removeGzipHeader($string) == Z_OK() |
816 | or return undef; |
817 | |
818 | my $bufsize = length $$string > 4096 ? length $$string : 4096 ; |
642e522c |
819 | my $x = new Compress::Zlib::Inflate({-WindowBits => - MAX_WBITS(), |
820 | -Bufsize => $bufsize}) |
821 | |
f4c6fd49 |
822 | or return undef; |
642e522c |
823 | |
824 | my $output = "" ; |
825 | my $status = $x->inflate($string, $output); |
f4c6fd49 |
826 | return undef |
827 | unless $status == Z_STREAM_END(); |
828 | |
829 | if (length $$string >= 8) |
830 | { |
831 | my ($crc, $len) = unpack ("VV", substr($$string, 0, 8)); |
832 | substr($$string, 0, 8) = ''; |
833 | return undef |
834 | unless $len == length($output) and |
835 | $crc == crc32($output); |
836 | } |
837 | else |
838 | { |
839 | $$string = ''; |
840 | } |
f4c6fd49 |
841 | return $output; |
842 | } |
843 | |
844 | # Autoload methods go after __END__, and are processed by the autosplit program. |
845 | |
846 | 1; |
847 | __END__ |
848 | |
f4c6fd49 |
849 | |
850 | =head1 NAME |
851 | |
852 | Compress::Zlib - Interface to zlib compression library |
853 | |
854 | =head1 SYNOPSIS |
855 | |
642e522c |
856 | use Compress::Zlib 2 ; |
f4c6fd49 |
857 | |
642e522c |
858 | ($d, $status) = new Compress::Zlib::Deflate( [OPT] ) ; |
859 | $status = $d->deflate($input, $output) ; |
860 | $status = $d->flush($output [, $flush_type]) ; |
861 | $d->deflateParams(OPTS) ; |
862 | $d->deflateTune(OPTS) ; |
f4c6fd49 |
863 | $d->dict_adler() ; |
642e522c |
864 | $d->crc32() ; |
865 | $d->adler32() ; |
f4c6fd49 |
866 | $d->total_in() ; |
867 | $d->total_out() ; |
868 | $d->msg() ; |
642e522c |
869 | $d->get_Strategy(); |
870 | $d->get_Level(); |
871 | $d->get_BufSize(); |
f4c6fd49 |
872 | |
642e522c |
873 | ($i, $status) = new Compress::Zlib::Inflate( [OPT] ) ; |
874 | $status = $i->inflate($input, $output) ; |
875 | $status = $i->inflateSync($input) ; |
f4c6fd49 |
876 | $i->dict_adler() ; |
642e522c |
877 | $d->crc32() ; |
878 | $d->adler32() ; |
f4c6fd49 |
879 | $i->total_in() ; |
880 | $i->total_out() ; |
881 | $i->msg() ; |
642e522c |
882 | $d->get_BufSize(); |
f4c6fd49 |
883 | |
642e522c |
884 | $dest = compress($source) ; |
f4c6fd49 |
885 | $dest = uncompress($source) ; |
886 | |
887 | $gz = gzopen($filename or filehandle, $mode) ; |
888 | $bytesread = $gz->gzread($buffer [,$size]) ; |
889 | $bytesread = $gz->gzreadline($line) ; |
890 | $byteswritten = $gz->gzwrite($buffer) ; |
891 | $status = $gz->gzflush($flush) ; |
642e522c |
892 | $offset = $gz->gztell() ; |
893 | $status = $gz->gzseek($offset, $whence) ; |
f4c6fd49 |
894 | $status = $gz->gzclose() ; |
895 | $status = $gz->gzeof() ; |
896 | $status = $gz->gzsetparams($level, $strategy) ; |
897 | $errstring = $gz->gzerror() ; |
898 | $gzerrno |
899 | |
900 | $dest = Compress::Zlib::memGzip($buffer) ; |
901 | $dest = Compress::Zlib::memGunzip($buffer) ; |
902 | |
903 | $crc = adler32($buffer [,$crc]) ; |
904 | $crc = crc32($buffer [,$crc]) ; |
905 | |
642e522c |
906 | $crc = adler32_combine($crc1, $crc2, $len2)l |
907 | $crc = crc32_combine($adler1, $adler2, $len2) |
908 | |
f4c6fd49 |
909 | ZLIB_VERSION |
642e522c |
910 | ZLIB_VERNUM |
911 | |
912 | # Compress::Zlib 1.x legacy interface |
913 | |
914 | ($d, $status) = deflateInit( [OPT] ) ; |
915 | ($out, $status) = $d->deflate($buffer) ; |
916 | $status = $d->deflateParams([OPT]) ; |
917 | ($out, $status) = $d->flush() ; |
918 | $d->dict_adler() ; |
919 | $d->total_in() ; |
920 | $d->total_out() ; |
921 | $d->msg() ; |
922 | |
923 | ($i, $status) = inflateInit( [OPT] ) ; |
924 | ($out, $status) = $i->inflate($buffer) ; |
925 | $status = $i->inflateSync($buffer) ; |
926 | $i->dict_adler() ; |
927 | $i->total_in() ; |
928 | $i->total_out() ; |
929 | $i->msg() ; |
930 | |
f4c6fd49 |
931 | |
932 | =head1 DESCRIPTION |
933 | |
934 | The I<Compress::Zlib> module provides a Perl interface to the I<zlib> |
935 | compression library (see L</AUTHOR> for details about where to get |
642e522c |
936 | I<zlib>). |
937 | The I<zlib> library allows reading and writing of |
938 | compressed data streams that conform to RFC1950, RFC1951 and RFC1952 |
939 | (aka gzip). |
940 | Most of the I<zlib> functionality is available in I<Compress::Zlib>. |
f4c6fd49 |
941 | |
642e522c |
942 | Unless you are working with legacy code, or you need to work directly |
943 | with the low-level zlib interface, it is recommended that applications |
944 | use one of the newer C<IO::*> interfaces provided with this module. |
f4c6fd49 |
945 | |
642e522c |
946 | The C<Compress::Zlib> module can be split into two general areas of |
947 | functionality, namely a low-level in-memory compression/decompression |
948 | interface and a simple read/write interface to I<gzip> files. |
f4c6fd49 |
949 | |
642e522c |
950 | Each of these areas will be discussed separately below. |
f4c6fd49 |
951 | |
f4c6fd49 |
952 | |
642e522c |
953 | =head1 GZIP INTERFACE |
f4c6fd49 |
954 | |
642e522c |
955 | A number of functions are supplied in I<zlib> for reading and writing |
956 | I<gzip> files that conform to RFC1952. This module provides an interface |
957 | to most of them. |
f4c6fd49 |
958 | |
642e522c |
959 | If you are upgrading from C<Compress::Zlib> 1.x, the following enhancements |
960 | have been made to the C<gzopen> interface: |
f4c6fd49 |
961 | |
642e522c |
962 | =over 5 |
f4c6fd49 |
963 | |
642e522c |
964 | =item 1 |
f4c6fd49 |
965 | |
642e522c |
966 | If you want to to open either STDIN or STDOUT with C<gzopen>, you can |
967 | optionally use the special filename "C<->" as a synonym for C<\*STDIN> and |
968 | C<\*STDOUT>. |
f4c6fd49 |
969 | |
642e522c |
970 | =item 2 |
f4c6fd49 |
971 | |
642e522c |
972 | In C<Compress::Zlib> version 1.x, C<gzopen> used the zlib library to open the |
973 | underlying file. This made things especially tricky when a Perl filehandle was |
974 | passed to C<gzopen>. Behind the scenes the numeric C file descriptor had to be |
975 | extracted from the Perl filehandle and this passed to the zlib library. |
f4c6fd49 |
976 | |
642e522c |
977 | Apart from being non-portable to some operating systems, this made it difficult |
978 | to use C<gzopen> in situations where you wanted to extract/create a gzip data |
979 | stream that is embedded in a larger file, without having to resort to opening |
980 | and closing the file multiple times. |
f4c6fd49 |
981 | |
642e522c |
982 | In C<Compress::Zlib> version 2.x, the C<gzopen> interface has been completely |
983 | rewritten to use the L<IO::Compress::Gzip|IO::Compress::Gzip> for writing gzip files and |
984 | L<IO::Uncompress::Gunzip|IO::Uncompress::Gunzip> for reading gzip files. |
f4c6fd49 |
985 | |
642e522c |
986 | =item 3 |
f4c6fd49 |
987 | |
642e522c |
988 | Addition of C<gzseek> to provide a restricted C<seek> interface. |
f4c6fd49 |
989 | |
642e522c |
990 | =item 4. |
f4c6fd49 |
991 | |
642e522c |
992 | Added C<gztell>. |
f4c6fd49 |
993 | |
642e522c |
994 | =back |
f4c6fd49 |
995 | |
642e522c |
996 | A more complete and flexible interface for reading/writing gzip files/buffers |
997 | is included with this module. See L<IO::Compress::Gzip|IO::Compress::Gzip> and |
998 | L<IO::Uncompress::Gunzip|IO::Uncompress::Gunzip> for more details. |
f4c6fd49 |
999 | |
642e522c |
1000 | =over 5 |
f4c6fd49 |
1001 | |
642e522c |
1002 | =item B<$gz = gzopen($filename, $mode)> |
f4c6fd49 |
1003 | |
642e522c |
1004 | =item B<$gz = gzopen($filehandle, $mode)> |
f4c6fd49 |
1005 | |
642e522c |
1006 | This function opens either the I<gzip> file C<$filename> for reading or writing |
1007 | or attaches to the opened filehandle, C<$filehandle>. It returns an object on |
1008 | success and C<undef> on failure. |
f4c6fd49 |
1009 | |
642e522c |
1010 | When writing a gzip file this interface will always create the smallest |
1011 | possible gzip header (exactly 10 bytes). If you want control over the |
1012 | information stored in the gzip header (like the original filename or a comment) |
1013 | use L<IO::Compress::Gzip|IO::Compress::Gzip> instead. |
f4c6fd49 |
1014 | |
642e522c |
1015 | The second parameter, C<$mode>, is used to specify whether the file is |
1016 | opened for reading or writing and to optionally specify a compression |
1017 | level and compression strategy when writing. The format of the C<$mode> |
1018 | parameter is similar to the mode parameter to the 'C' function C<fopen>, |
1019 | so "rb" is used to open for reading and "wb" for writing. |
f4c6fd49 |
1020 | |
642e522c |
1021 | To specify a compression level when writing, append a digit between 0 |
1022 | and 9 to the mode string -- 0 means no compression and 9 means maximum |
1023 | compression. |
1024 | If no compression level is specified Z_DEFAULT_COMPRESSION is used. |
f4c6fd49 |
1025 | |
642e522c |
1026 | To specify the compression strategy when writing, append 'f' for filtered |
1027 | data, 'h' for Huffman only compression, or 'R' for run-length encoding. |
1028 | If no strategy is specified Z_DEFAULT_STRATEGY is used. |
f4c6fd49 |
1029 | |
642e522c |
1030 | So, for example, "wb9" means open for writing with the maximum compression |
1031 | using the default strategy and "wb4R" means open for writing with compression |
1032 | level 4 and run-length encoding. |
f4c6fd49 |
1033 | |
642e522c |
1034 | Refer to the I<zlib> documentation for the exact format of the C<$mode> |
1035 | parameter. |
f4c6fd49 |
1036 | |
f4c6fd49 |
1037 | |
642e522c |
1038 | =item B<$bytesread = $gz-E<gt>gzread($buffer [, $size]) ;> |
1039 | |
1040 | Reads C<$size> bytes from the compressed file into C<$buffer>. If |
1041 | C<$size> is not specified, it will default to 4096. If the scalar |
1042 | C<$buffer> is not large enough, it will be extended automatically. |
1043 | |
1044 | Returns the number of bytes actually read. On EOF it returns 0 and in |
1045 | the case of an error, -1. |
1046 | |
1047 | =item B<$bytesread = $gz-E<gt>gzreadline($line) ;> |
1048 | |
1049 | Reads the next line from the compressed file into C<$line>. |
1050 | |
1051 | Returns the number of bytes actually read. On EOF it returns 0 and in |
1052 | the case of an error, -1. |
1053 | |
1054 | It is legal to intermix calls to C<gzread> and C<gzreadline>. |
1055 | |
1056 | In addition, C<gzreadline> fully supports the use of of the variable C<$/> |
1057 | (C<$INPUT_RECORD_SEPARATOR> or C<$RS> when C<English> is in use) to |
1058 | determine what constitutes an end of line. Both paragraph mode and file |
1059 | slurp mode are supported. |
1060 | |
1061 | |
1062 | =item B<$byteswritten = $gz-E<gt>gzwrite($buffer) ;> |
1063 | |
1064 | Writes the contents of C<$buffer> to the compressed file. Returns the |
1065 | number of bytes actually written, or 0 on error. |
1066 | |
1067 | =item B<$status = $gz-E<gt>gzflush($flush_type) ;> |
1068 | |
1069 | Flushes all pending output into the compressed file. |
1070 | |
1071 | This method takes an optional parameter, C<$flush_type>, that controls |
1072 | how the flushing will be carried out. By default the C<$flush_type> |
1073 | used is C<Z_FINISH>. Other valid values for C<$flush_type> are |
1074 | C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is |
1075 | strongly recommended that you only set the C<flush_type> parameter if |
1076 | you fully understand the implications of what it does - overuse of C<flush> |
1077 | can seriously degrade the level of compression achieved. See the C<zlib> |
1078 | documentation for details. |
1079 | |
1080 | Returns 1 on success, 0 on failure. |
1081 | |
1082 | |
1083 | =item B<$offset = $gz-E<gt>gztell() ;> |
1084 | |
1085 | Returns the uncompressed file offset. |
1086 | |
1087 | =item B<$status = $gz-E<gt>gzseek($offset, $whence) ;> |
1088 | |
1089 | Sets the file position of the |
1090 | |
1091 | Provides a sub-set of the C<seek> functionality, with the restriction |
1092 | that it is only legal to seek forward in the compressed file. |
1093 | It is a fatal error to attempt to seek backward. |
1094 | |
1095 | When opened for writing, empty parts of the file will have NULL (0x00) |
1096 | bytes written to them. |
1097 | |
1098 | The C<$whence> parameter should be one of SEEK_SET, SEEK_CUR or SEEK_END. |
1099 | |
1100 | Returns 1 on success, 0 on failure. |
1101 | |
1102 | =item B<$gz-E<gt>gzclose> |
1103 | |
1104 | Closes the compressed file. Any pending data is flushed to the file |
1105 | before it is closed. |
1106 | |
1107 | Returns 1 on success, 0 on failure. |
1108 | |
1109 | =item B<$gz-E<gt>gzsetparams($level, $strategy> |
1110 | |
1111 | Change settings for the deflate stream C<$gz>. |
1112 | |
1113 | The list of the valid options is shown below. Options not specified |
1114 | will remain unchanged. |
1115 | |
1116 | Note: This method is only available if you are running zlib 1.0.6 or better. |
1117 | |
1118 | =over 5 |
1119 | |
1120 | =item B<$level> |
1121 | |
1122 | Defines the compression level. Valid values are 0 through 9, |
1123 | C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, C<Z_BEST_COMPRESSION>, and |
1124 | C<Z_DEFAULT_COMPRESSION>. |
1125 | |
1126 | =item B<$strategy> |
1127 | |
1128 | Defines the strategy used to tune the compression. The valid values are |
1129 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED> and C<Z_HUFFMAN_ONLY>. |
1130 | |
1131 | =back |
1132 | |
1133 | =item B<$gz-E<gt>gzerror> |
1134 | |
1135 | Returns the I<zlib> error message or number for the last operation |
1136 | associated with C<$gz>. The return value will be the I<zlib> error |
1137 | number when used in a numeric context and the I<zlib> error message |
1138 | when used in a string context. The I<zlib> error number constants, |
1139 | shown below, are available for use. |
1140 | |
1141 | Z_OK |
1142 | Z_STREAM_END |
1143 | Z_ERRNO |
1144 | Z_STREAM_ERROR |
1145 | Z_DATA_ERROR |
1146 | Z_MEM_ERROR |
1147 | Z_BUF_ERROR |
1148 | |
1149 | =item B<$gzerrno> |
1150 | |
1151 | The C<$gzerrno> scalar holds the error code associated with the most |
1152 | recent I<gzip> routine. Note that unlike C<gzerror()>, the error is |
1153 | I<not> associated with a particular file. |
1154 | |
1155 | As with C<gzerror()> it returns an error number in numeric context and |
1156 | an error message in string context. Unlike C<gzerror()> though, the |
1157 | error message will correspond to the I<zlib> message when the error is |
1158 | associated with I<zlib> itself, or the UNIX error message when it is |
1159 | not (i.e. I<zlib> returned C<Z_ERRORNO>). |
1160 | |
1161 | As there is an overlap between the error numbers used by I<zlib> and |
1162 | UNIX, C<$gzerrno> should only be used to check for the presence of |
1163 | I<an> error in numeric context. Use C<gzerror()> to check for specific |
1164 | I<zlib> errors. The I<gzcat> example below shows how the variable can |
1165 | be used safely. |
1166 | |
1167 | =back |
1168 | |
1169 | |
1170 | =head2 Examples |
1171 | |
1172 | Here is an example script which uses the interface. It implements a |
1173 | I<gzcat> function. |
1174 | |
1175 | use strict ; |
1176 | use warnings ; |
1177 | |
1178 | use Compress::Zlib ; |
1179 | |
1180 | # use stdin if no files supplied |
1181 | @ARGV = '-' unless @ARGV ; |
1182 | |
1183 | foreach my $file (@ARGV) { |
1184 | my $buffer ; |
1185 | |
1186 | my $gz = gzopen($file, "rb") |
1187 | or die "Cannot open $file: $gzerrno\n" ; |
1188 | |
1189 | print $buffer while $gz->gzread($buffer) > 0 ; |
1190 | |
1191 | die "Error reading from $file: $gzerrno" . ($gzerrno+0) . "\n" |
1192 | if $gzerrno != Z_STREAM_END ; |
1193 | |
1194 | $gz->gzclose() ; |
1195 | } |
1196 | |
1197 | Below is a script which makes use of C<gzreadline>. It implements a |
1198 | very simple I<grep> like script. |
1199 | |
1200 | use strict ; |
1201 | use warnings ; |
1202 | |
1203 | use Compress::Zlib ; |
1204 | |
1205 | die "Usage: gzgrep pattern [file...]\n" |
1206 | unless @ARGV >= 1; |
1207 | |
1208 | my $pattern = shift ; |
1209 | |
1210 | # use stdin if no files supplied |
1211 | @ARGV = '-' unless @ARGV ; |
1212 | |
1213 | foreach my $file (@ARGV) { |
1214 | my $gz = gzopen($file, "rb") |
1215 | or die "Cannot open $file: $gzerrno\n" ; |
1216 | |
1217 | while ($gz->gzreadline($_) > 0) { |
1218 | print if /$pattern/ ; |
1219 | } |
1220 | |
1221 | die "Error reading from $file: $gzerrno\n" |
1222 | if $gzerrno != Z_STREAM_END ; |
1223 | |
1224 | $gz->gzclose() ; |
1225 | } |
1226 | |
1227 | This script, I<gzstream>, does the opposite of the I<gzcat> script |
1228 | above. It reads from standard input and writes a gzip data stream to |
1229 | standard output. |
1230 | |
1231 | use strict ; |
1232 | use warnings ; |
1233 | |
1234 | use Compress::Zlib ; |
1235 | |
1236 | binmode STDOUT; # gzopen only sets it on the fd |
1237 | |
1238 | my $gz = gzopen(\*STDOUT, "wb") |
1239 | or die "Cannot open stdout: $gzerrno\n" ; |
1240 | |
1241 | while (<>) { |
1242 | $gz->gzwrite($_) |
1243 | or die "error writing: $gzerrno\n" ; |
1244 | } |
1245 | |
1246 | $gz->gzclose ; |
1247 | |
1248 | =head2 Compress::Zlib::memGzip |
1249 | |
1250 | This function is used to create an in-memory gzip file with the minimum |
1251 | possible gzip header (exactly 10 bytes). |
1252 | |
1253 | $dest = Compress::Zlib::memGzip($buffer) ; |
1254 | |
1255 | If successful, it returns the in-memory gzip file, otherwise it returns |
1256 | undef. |
1257 | |
1258 | The C<$buffer> parameter can either be a scalar or a scalar reference. |
1259 | |
1260 | See L<IO::Compress::Gzip|IO::Compress::Gzip> for an alternative way to carry out in-memory gzip |
1261 | compression. |
1262 | |
1263 | =head2 Compress::Zlib::memGunzip |
1264 | |
1265 | This function is used to uncompress an in-memory gzip file. |
1266 | |
1267 | $dest = Compress::Zlib::memGunzip($buffer) ; |
1268 | |
1269 | If successful, it returns the uncompressed gzip file, otherwise it |
1270 | returns undef. |
1271 | |
1272 | The C<$buffer> parameter can either be a scalar or a scalar reference. The |
1273 | contents of the C<$buffer> parameter are destroyed after calling this function. |
1274 | |
1275 | See L<IO::Uncompress::Gunzip|IO::Uncompress::Gunzip> for an alternative way to carry out in-memory gzip |
1276 | uncompression. |
1277 | |
1278 | =head1 COMPRESS/UNCOMPRESS |
1279 | |
1280 | Two functions are provided to perform in-memory compression/uncompression of |
1281 | RFC 1950 data streams. They are called C<compress> and C<uncompress>. |
1282 | |
1283 | =over 5 |
1284 | |
1285 | =item B<$dest = compress($source [, $level] ) ;> |
1286 | |
1287 | Compresses C<$source>. If successful it returns the compressed |
1288 | data. Otherwise it returns I<undef>. |
1289 | |
1290 | The source buffer, C<$source>, can either be a scalar or a scalar |
1291 | reference. |
1292 | |
1293 | The C<$level> parameter defines the compression level. Valid values are |
1294 | 0 through 9, C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, |
1295 | C<Z_BEST_COMPRESSION>, and C<Z_DEFAULT_COMPRESSION>. |
1296 | If C<$level> is not specified C<Z_DEFAULT_COMPRESSION> will be used. |
1297 | |
1298 | |
1299 | =item B<$dest = uncompress($source) ;> |
1300 | |
1301 | Uncompresses C<$source>. If successful it returns the uncompressed |
1302 | data. Otherwise it returns I<undef>. |
1303 | |
1304 | The source buffer can either be a scalar or a scalar reference. |
1305 | |
1306 | =back |
1307 | |
1308 | Please note: the two functions defined above are I<not> compatible with |
1309 | the Unix commands of the same name. |
1310 | |
1311 | See L<IO::Compress::Deflate|IO::Compress::Deflate> and L<IO::Uncompress::Inflate|IO::Uncompress::Inflate> included with |
1312 | this distribution for an alternative interface for reading/writing RFC 1950 |
1313 | files/buffers. |
1314 | |
1315 | =head1 CHECKSUM FUNCTIONS |
1316 | |
1317 | Two functions are provided by I<zlib> to calculate checksums. For the |
1318 | Perl interface, the order of the two parameters in both functions has |
1319 | been reversed. This allows both running checksums and one off |
1320 | calculations to be done. |
1321 | |
1322 | $crc = adler32($buffer [,$crc]) ; |
1323 | $crc = crc32($buffer [,$crc]) ; |
1324 | |
1325 | The buffer parameters can either be a scalar or a scalar reference. |
1326 | |
1327 | If the $crc parameters is C<undef>, the crc value will be reset. |
1328 | |
1329 | If you have built this module with zlib 1.2.3 or better, two more |
1330 | CRC-related functions are available. |
1331 | |
1332 | $crc = adler32_combine($crc1, $crc2, $len2)l |
1333 | $crc = crc32_combine($adler1, $adler2, $len2) |
1334 | |
1335 | These functions allow checksums to be merged. |
1336 | |
1337 | =head1 Compress::Zlib::Deflate |
1338 | |
1339 | This section defines an interface that allows in-memory compression using |
1340 | the I<deflate> interface provided by zlib. |
1341 | |
1342 | Note: The interface defined in this section is different from version |
1343 | 1.x of this module. The original deflate interface is still available |
1344 | for backward compatibility and is documented in the section |
1345 | L<Compress::Zlib 1.x Deflate Interface>. |
1346 | |
1347 | Here is a definition of the interface available: |
1348 | |
1349 | |
1350 | =head2 B<($d, $status) = new Compress::Zlib::Deflate( [OPT] ) > |
1351 | |
1352 | Initialises a deflation object. |
1353 | |
1354 | If you are familiar with the I<zlib> library, it combines the |
1355 | features of the I<zlib> functions C<deflateInit>, C<deflateInit2> |
1356 | and C<deflateSetDictionary>. |
1357 | |
1358 | If successful, it will return the initialised deflation object, C<$d> |
1359 | and a C<$status> of C<Z_OK> in a list context. In scalar context it |
1360 | returns the deflation object, C<$d>, only. |
1361 | |
1362 | If not successful, the returned deflation object, C<$d>, will be |
1363 | I<undef> and C<$status> will hold the a I<zlib> error code. |
1364 | |
1365 | The function optionally takes a number of named options specified as |
1366 | C<-Name =E<gt> value> pairs. This allows individual options to be |
1367 | tailored without having to specify them all in the parameter list. |
1368 | |
1369 | For backward compatibility, it is also possible to pass the parameters |
1370 | as a reference to a hash containing the name=>value pairs. |
1371 | |
1372 | Below is a list of the valid options: |
1373 | |
1374 | =over 5 |
1375 | |
1376 | =item B<-Level> |
1377 | |
1378 | Defines the compression level. Valid values are 0 through 9, |
1379 | C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, C<Z_BEST_COMPRESSION>, and |
1380 | C<Z_DEFAULT_COMPRESSION>. |
1381 | |
1382 | The default is C<-Level =E<gt> Z_DEFAULT_COMPRESSION>. |
1383 | |
1384 | =item B<-Method> |
1385 | |
1386 | Defines the compression method. The only valid value at present (and |
1387 | the default) is C<-Method =E<gt> Z_DEFLATED>. |
1388 | |
1389 | =item B<-WindowBits> |
1390 | |
1391 | For a definition of the meaning and valid values for C<WindowBits> |
1392 | refer to the I<zlib> documentation for I<deflateInit2>. |
1393 | |
1394 | Defaults to C<-WindowBits =E<gt> MAX_WBITS>. |
1395 | |
1396 | =item B<-MemLevel> |
1397 | |
1398 | For a definition of the meaning and valid values for C<MemLevel> |
1399 | refer to the I<zlib> documentation for I<deflateInit2>. |
1400 | |
1401 | Defaults to C<-MemLevel =E<gt> MAX_MEM_LEVEL>. |
1402 | |
1403 | =item B<-Strategy> |
1404 | |
1405 | Defines the strategy used to tune the compression. The valid values are |
1406 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED>, C<Z_RLE>, C<Z_FIXED> and |
1407 | C<Z_HUFFMAN_ONLY>. |
1408 | |
1409 | The default is C<-Strategy =E<gt>Z_DEFAULT_STRATEGY>. |
1410 | |
1411 | =item B<-Dictionary> |
1412 | |
1413 | When a dictionary is specified I<Compress::Zlib> will automatically |
1414 | call C<deflateSetDictionary> directly after calling C<deflateInit>. The |
1415 | Adler32 value for the dictionary can be obtained by calling the method |
1416 | C<$d-E<gt>dict_adler()>. |
f4c6fd49 |
1417 | |
1418 | The default is no dictionary. |
1419 | |
1420 | =item B<-Bufsize> |
1421 | |
642e522c |
1422 | Sets the initial size for the output buffer used by the C<$d-E<gt>deflate> |
1423 | and C<$d-E<gt>flush> methods. If the buffer has to be |
f4c6fd49 |
1424 | reallocated to increase the size, it will grow in increments of |
642e522c |
1425 | C<Bufsize>. |
1426 | |
1427 | The default buffer size is 4096. |
1428 | |
1429 | =item B<-AppendOutput> |
1430 | |
1431 | This option controls how data is written to the output buffer by the |
1432 | C<$d-E<gt>deflate> and C<$d-E<gt>flush> methods. |
1433 | |
1434 | If the C<AppendOutput> option is set to false, the output buffers in the |
1435 | C<$d-E<gt>deflate> and C<$d-E<gt>flush> methods will be truncated before |
1436 | uncompressed data is written to them. |
1437 | |
1438 | If the option is set to true, uncompressed data will be appended to the |
1439 | output buffer in the C<$d-E<gt>deflate> and C<$d-E<gt>flush> methods. |
1440 | |
1441 | This option defaults to false. |
1442 | |
1443 | =item B<-CRC32> |
1444 | |
1445 | If set to true, a crc32 checksum of the uncompressed data will be |
1446 | calculated. Use the C<$d-E<gt>crc32> method to retrieve this value. |
1447 | |
1448 | This option defaults to false. |
1449 | |
1450 | |
1451 | =item B<-ADLER32> |
1452 | |
1453 | If set to true, an adler32 checksum of the uncompressed data will be |
1454 | calculated. Use the C<$d-E<gt>adler32> method to retrieve this value. |
1455 | |
1456 | This option defaults to false. |
f4c6fd49 |
1457 | |
f4c6fd49 |
1458 | |
1459 | =back |
1460 | |
642e522c |
1461 | Here is an example of using the C<Compress::Zlib::Deflate> optional |
1462 | parameter list to override the default buffer size and compression |
1463 | level. All other options will take their default values. |
f4c6fd49 |
1464 | |
642e522c |
1465 | my $d = new Compress::Zlib::Deflate ( -Bufsize => 300, |
1466 | -Level => Z_BEST_SPEED ) ; |
f4c6fd49 |
1467 | |
1468 | |
642e522c |
1469 | =head2 B<$status = $d-E<gt>deflate($input, $output)> |
f4c6fd49 |
1470 | |
642e522c |
1471 | Deflates the contents of C<$input> and writes the compressed data to |
1472 | C<$output>. |
f4c6fd49 |
1473 | |
642e522c |
1474 | The C<$input> and C<$output> parameters can be either scalars or scalar |
1475 | references. |
f4c6fd49 |
1476 | |
642e522c |
1477 | When finished, C<$input> will be completely processed (assuming there |
1478 | were no errors). If the deflation was successful it writes the deflated |
1479 | data to C<$output> and returns a status value of C<Z_OK>. |
f4c6fd49 |
1480 | |
642e522c |
1481 | On error, it returns a I<zlib> error code. |
f4c6fd49 |
1482 | |
642e522c |
1483 | If the C<AppendOutput> option is set to true in the constructor for |
1484 | the C<$d> object, the compressed data will be appended to C<$output>. If |
1485 | it is false, C<$output> will be truncated before any compressed data is |
1486 | written to it. |
f4c6fd49 |
1487 | |
642e522c |
1488 | B<Note>: This method will not necessarily write compressed data to |
1489 | C<$output> every time it is called. So do not assume that there has been |
1490 | an error if the contents of C<$output> is empty on returning from |
1491 | this method. As long as the return code from the method is C<Z_OK>, |
1492 | the deflate has succeeded. |
f4c6fd49 |
1493 | |
642e522c |
1494 | =head2 B<$status = $d-E<gt>flush($output [, $flush_type]) > |
f4c6fd49 |
1495 | |
1496 | Typically used to finish the deflation. Any pending output will be |
642e522c |
1497 | written to C<$output>. |
f4c6fd49 |
1498 | |
642e522c |
1499 | Returns C<Z_OK> if successful. |
f4c6fd49 |
1500 | |
1501 | Note that flushing can seriously degrade the compression ratio, so it |
1502 | should only be used to terminate a decompression (using C<Z_FINISH>) or |
1503 | when you want to create a I<full flush point> (using C<Z_FULL_FLUSH>). |
1504 | |
1505 | By default the C<flush_type> used is C<Z_FINISH>. Other valid values |
1506 | for C<flush_type> are C<Z_NO_FLUSH>, C<Z_PARTIAL_FLUSH>, C<Z_SYNC_FLUSH> |
1507 | and C<Z_FULL_FLUSH>. It is strongly recommended that you only set the |
1508 | C<flush_type> parameter if you fully understand the implications of |
1509 | what it does. See the C<zlib> documentation for details. |
1510 | |
642e522c |
1511 | If the C<AppendOutput> option is set to true in the constructor for |
1512 | the C<$d> object, the compressed data will be appended to C<$output>. If |
1513 | it is false, C<$output> will be truncated before any compressed data is |
1514 | written to it. |
1515 | |
f4c6fd49 |
1516 | =head2 B<$status = $d-E<gt>deflateParams([OPT])> |
1517 | |
642e522c |
1518 | Change settings for the deflate object C<$d>. |
f4c6fd49 |
1519 | |
1520 | The list of the valid options is shown below. Options not specified |
1521 | will remain unchanged. |
1522 | |
642e522c |
1523 | |
f4c6fd49 |
1524 | =over 5 |
1525 | |
1526 | =item B<-Level> |
1527 | |
1528 | Defines the compression level. Valid values are 0 through 9, |
1529 | C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, C<Z_BEST_COMPRESSION>, and |
1530 | C<Z_DEFAULT_COMPRESSION>. |
1531 | |
1532 | =item B<-Strategy> |
1533 | |
1534 | Defines the strategy used to tune the compression. The valid values are |
1535 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED> and C<Z_HUFFMAN_ONLY>. |
1536 | |
642e522c |
1537 | =item B<-BufSize> |
1538 | |
1539 | Sets the initial size for the output buffer used by the C<$d-E<gt>deflate> |
1540 | and C<$d-E<gt>flush> methods. If the buffer has to be |
1541 | reallocated to increase the size, it will grow in increments of |
1542 | C<Bufsize>. |
1543 | |
1544 | |
f4c6fd49 |
1545 | =back |
1546 | |
642e522c |
1547 | =head2 B<$status = $d-E<gt>deflateTune($good_length, $max_lazy, $nice_length, $max_chain)> |
1548 | |
1549 | Tune the internal settings for the deflate object C<$d>. This option is |
1550 | only available if you are running zlib 1.2.2.3 or better. |
1551 | |
1552 | Refer to the documentation in zlib.h for instructions on how to fly |
1553 | C<deflateTune>. |
1554 | |
f4c6fd49 |
1555 | =head2 B<$d-E<gt>dict_adler()> |
1556 | |
1557 | Returns the adler32 value for the dictionary. |
1558 | |
642e522c |
1559 | =head2 B<$d-E<gt>crc32()> |
1560 | |
1561 | Returns the crc32 value for the uncompressed data to date. |
1562 | |
1563 | If the C<CRC32> option is not enabled in the constructor for this object, |
1564 | this method will always return 0; |
1565 | |
1566 | =head2 B<$d-E<gt>adler32()> |
1567 | |
1568 | Returns the adler32 value for the uncompressed data to date. |
1569 | |
f4c6fd49 |
1570 | =head2 B<$d-E<gt>msg()> |
1571 | |
1572 | Returns the last error message generated by zlib. |
1573 | |
1574 | =head2 B<$d-E<gt>total_in()> |
1575 | |
1576 | Returns the total number of bytes uncompressed bytes input to deflate. |
1577 | |
1578 | =head2 B<$d-E<gt>total_out()> |
1579 | |
1580 | Returns the total number of compressed bytes output from deflate. |
1581 | |
642e522c |
1582 | =head2 B<$d-E<gt>get_Strategy()> |
1583 | |
1584 | Returns the deflation strategy currently used. Valid values are |
1585 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED> and C<Z_HUFFMAN_ONLY>. |
1586 | |
1587 | |
1588 | =head2 B<$d-E<gt>get_Level()> |
1589 | |
1590 | Returns the compression level being used. |
1591 | |
1592 | =head2 B<$d-E<gt>get_BufSize()> |
1593 | |
1594 | Returns the buffer size used to carry out the compression. |
1595 | |
f4c6fd49 |
1596 | =head2 Example |
1597 | |
1598 | |
642e522c |
1599 | Here is a trivial example of using C<deflate>. It simply reads standard |
f4c6fd49 |
1600 | input, deflates it and writes it to standard output. |
1601 | |
1602 | use strict ; |
1603 | use warnings ; |
1604 | |
642e522c |
1605 | use Compress::Zlib 2 ; |
f4c6fd49 |
1606 | |
1607 | binmode STDIN; |
1608 | binmode STDOUT; |
642e522c |
1609 | my $x = new Compress::Zlib::Deflate |
f4c6fd49 |
1610 | or die "Cannot create a deflation stream\n" ; |
1611 | |
1612 | my ($output, $status) ; |
1613 | while (<>) |
1614 | { |
642e522c |
1615 | $status = $x->deflate($_, $output) ; |
f4c6fd49 |
1616 | |
1617 | $status == Z_OK |
1618 | or die "deflation failed\n" ; |
1619 | |
1620 | print $output ; |
1621 | } |
1622 | |
642e522c |
1623 | $status = $x->flush($output) ; |
f4c6fd49 |
1624 | |
1625 | $status == Z_OK |
1626 | or die "deflation failed\n" ; |
1627 | |
1628 | print $output ; |
1629 | |
642e522c |
1630 | =head1 Compress::Zlib::Inflate |
1631 | |
1632 | This section defines an interface that allows in-memory uncompression using |
1633 | the I<inflate> interface provided by zlib. |
1634 | |
1635 | Note: The interface defined in this section is different from version |
1636 | 1.x of this module. The original inflate interface is still available |
1637 | for backward compatibility and is documented in the section |
1638 | L<Compress::Zlib 1.x Inflate Interface>. |
f4c6fd49 |
1639 | |
1640 | Here is a definition of the interface: |
1641 | |
1642 | |
642e522c |
1643 | =head2 B< ($i, $status) = new Compress::Zlib::Inflate( [OPT] ) > |
f4c6fd49 |
1644 | |
642e522c |
1645 | Initialises an inflation object. |
f4c6fd49 |
1646 | |
642e522c |
1647 | In a list context it returns the inflation object, C<$i>, and the |
1648 | I<zlib> status code (C<$status>). In a scalar context it returns the |
1649 | inflation object only. |
f4c6fd49 |
1650 | |
642e522c |
1651 | If successful, C<$i> will hold the inflation object and C<$status> will |
f4c6fd49 |
1652 | be C<Z_OK>. |
1653 | |
642e522c |
1654 | If not successful, C<$i> will be I<undef> and C<$status> will hold the |
f4c6fd49 |
1655 | I<zlib> error code. |
1656 | |
1657 | The function optionally takes a number of named options specified as |
642e522c |
1658 | C<-Name =E<gt> value> pairs. This allows individual options to be |
f4c6fd49 |
1659 | tailored without having to specify them all in the parameter list. |
642e522c |
1660 | |
f4c6fd49 |
1661 | For backward compatibility, it is also possible to pass the parameters |
642e522c |
1662 | as a reference to a hash containing the name=E<gt>value pairs. |
1663 | |
f4c6fd49 |
1664 | Here is a list of the valid options: |
1665 | |
1666 | =over 5 |
1667 | |
1668 | =item B<-WindowBits> |
1669 | |
642e522c |
1670 | For a definition of the meaning and valid values for C<WindowBits> |
f4c6fd49 |
1671 | refer to the I<zlib> documentation for I<inflateInit2>. |
1672 | |
1673 | Defaults to C<-WindowBits =E<gt>MAX_WBITS>. |
1674 | |
1675 | =item B<-Bufsize> |
1676 | |
642e522c |
1677 | Sets the initial size for the output buffer used by the C<$i-E<gt>inflate> |
1678 | method. If the output buffer in this method has to be reallocated to |
1679 | increase the size, it will grow in increments of C<Bufsize>. |
f4c6fd49 |
1680 | |
1681 | Default is 4096. |
1682 | |
1683 | =item B<-Dictionary> |
1684 | |
1685 | The default is no dictionary. |
1686 | |
642e522c |
1687 | =item B<-AppendOutput> |
1688 | |
1689 | This option controls how data is written to the output buffer by the |
1690 | C<$i-E<gt>inflate> method. |
1691 | |
1692 | If the option is set to false, the output buffer in the C<$i-E<gt>inflate> |
1693 | method will be truncated before uncompressed data is written to it. |
1694 | |
1695 | If the option is set to true, uncompressed data will be appended to the |
1696 | output buffer by the C<$i-E<gt>inflate> method. |
1697 | |
1698 | This option defaults to false. |
1699 | |
1700 | |
1701 | =item B<-CRC32> |
1702 | |
1703 | If set to true, a crc32 checksum of the uncompressed data will be |
1704 | calculated. Use the C<$i-E<gt>crc32> method to retrieve this value. |
1705 | |
1706 | This option defaults to false. |
1707 | |
1708 | =item B<-ADLER32> |
1709 | |
1710 | If set to true, an adler32 checksum of the uncompressed data will be |
1711 | calculated. Use the C<$i-E<gt>adler32> method to retrieve this value. |
1712 | |
1713 | This option defaults to false. |
1714 | |
1715 | =item B<-ConsumeInput> |
1716 | |
1717 | If set to true, this option will remove compressed data from the input |
1718 | buffer of the the C< $i-E<gt>inflate > method as the inflate progresses. |
1719 | |
1720 | This option can be useful when you are processing compressed data that is |
1721 | embedded in another file/buffer. In this case the data that immediately |
1722 | follows the compressed stream will be left in the input buffer. |
1723 | |
1724 | This option defaults to true. |
1725 | |
f4c6fd49 |
1726 | =back |
1727 | |
642e522c |
1728 | Here is an example of using an optional parameter to override the default |
1729 | buffer size. |
f4c6fd49 |
1730 | |
642e522c |
1731 | my ($i, $status) = new Compress::Zlib::Inflate( -Bufsize => 300 ) ; |
f4c6fd49 |
1732 | |
642e522c |
1733 | =head2 B< $status = $i-E<gt>inflate($input, $output) > |
f4c6fd49 |
1734 | |
642e522c |
1735 | Inflates the complete contents of C<$input> and writes the uncompressed |
1736 | data to C<$output>. The C<$input> and C<$output> parameters can either be |
1737 | scalars or scalar references. |
f4c6fd49 |
1738 | |
1739 | Returns C<Z_OK> if successful and C<Z_STREAM_END> if the end of the |
1740 | compressed data has been successfully reached. |
f4c6fd49 |
1741 | |
642e522c |
1742 | If not successful C<$status> will hold the I<zlib> error code. |
1743 | |
1744 | If the C<ConsumeInput> option has been set to true when the |
1745 | C<Compress::Zlib::Inflate> object is created, the C<$input> parameter |
1746 | is modified by C<inflate>. On completion it will contain what remains |
1747 | of the input buffer after inflation. In practice, this means that when |
1748 | the return status is C<Z_OK> the C<$input> parameter will contain an |
1749 | empty string, and when the return status is C<Z_STREAM_END> the C<$input> |
1750 | parameter will contains what (if anything) was stored in the input buffer |
1751 | after the deflated data stream. |
f4c6fd49 |
1752 | |
1753 | This feature is useful when processing a file format that encapsulates |
642e522c |
1754 | a compressed data stream (e.g. gzip, zip) and there is useful data |
1755 | immediately after the deflation stream. |
f4c6fd49 |
1756 | |
642e522c |
1757 | If the C<AppendOutput> option is set to true in the constructor for |
1758 | this object, the uncompressed data will be appended to C<$output>. If |
1759 | it is false, C<$output> will be truncated before any uncompressed data |
1760 | is written to it. |
f4c6fd49 |
1761 | |
642e522c |
1762 | =head2 B<$status = $i-E<gt>inflateSync($input)> |
1763 | |
1764 | This method can be used to attempt to recover good data from a compressed |
1765 | data stream that is partially corrupt. |
1766 | It scans C<$input> until it reaches either a I<full flush point> or the |
f4c6fd49 |
1767 | end of the buffer. |
1768 | |
642e522c |
1769 | If a I<full flush point> is found, C<Z_OK> is returned and C<$input> |
1770 | will be have all data up to the flush point removed. This data can then be |
1771 | passed to the C<$i-E<gt>inflate> method to be uncompressed. |
f4c6fd49 |
1772 | |
1773 | Any other return code means that a flush point was not found. If more |
1774 | data is available, C<inflateSync> can be called repeatedly with more |
1775 | compressed data until the flush point is found. |
1776 | |
642e522c |
1777 | Note I<full flush points> are not present by default in compressed |
1778 | data streams. They must have been added explicitly when the data stream |
1779 | was created by calling C<Compress::Deflate::flush> with C<Z_FULL_FLUSH>. |
1780 | |
f4c6fd49 |
1781 | |
1782 | =head2 B<$i-E<gt>dict_adler()> |
1783 | |
1784 | Returns the adler32 value for the dictionary. |
1785 | |
642e522c |
1786 | =head2 B<$i-E<gt>crc32()> |
1787 | |
1788 | Returns the crc32 value for the uncompressed data to date. |
1789 | |
1790 | If the C<CRC32> option is not enabled in the constructor for this object, |
1791 | this method will always return 0; |
1792 | |
1793 | =head2 B<$i-E<gt>adler32()> |
1794 | |
1795 | Returns the adler32 value for the uncompressed data to date. |
1796 | |
1797 | If the C<ADLER32> option is not enabled in the constructor for this object, |
1798 | this method will always return 0; |
1799 | |
f4c6fd49 |
1800 | =head2 B<$i-E<gt>msg()> |
1801 | |
1802 | Returns the last error message generated by zlib. |
1803 | |
1804 | =head2 B<$i-E<gt>total_in()> |
1805 | |
1806 | Returns the total number of bytes compressed bytes input to inflate. |
1807 | |
1808 | =head2 B<$i-E<gt>total_out()> |
1809 | |
1810 | Returns the total number of uncompressed bytes output from inflate. |
1811 | |
642e522c |
1812 | =head2 B<$d-E<gt>get_BufSize()> |
1813 | |
1814 | Returns the buffer size used to carry out the decompression. |
1815 | |
f4c6fd49 |
1816 | =head2 Example |
1817 | |
642e522c |
1818 | Here is an example of using C<inflate>. |
f4c6fd49 |
1819 | |
1820 | use strict ; |
1821 | use warnings ; |
1822 | |
642e522c |
1823 | use Compress::Zlib 2 ; |
f4c6fd49 |
1824 | |
642e522c |
1825 | my $x = new Compress::Zlib::Inflate() |
f4c6fd49 |
1826 | or die "Cannot create a inflation stream\n" ; |
1827 | |
1828 | my $input = '' ; |
1829 | binmode STDIN; |
1830 | binmode STDOUT; |
1831 | |
1832 | my ($output, $status) ; |
1833 | while (read(STDIN, $input, 4096)) |
1834 | { |
642e522c |
1835 | $status = $x->inflate(\$input, $output) ; |
f4c6fd49 |
1836 | |
1837 | print $output |
1838 | if $status == Z_OK or $status == Z_STREAM_END ; |
1839 | |
1840 | last if $status != Z_OK ; |
1841 | } |
1842 | |
1843 | die "inflation failed\n" |
1844 | unless $status == Z_STREAM_END ; |
1845 | |
642e522c |
1846 | =head1 Compress::Zlib 1.x Deflate Interface |
1847 | |
1848 | This section defines the interface available in C<Compress::Zlib> version |
1849 | 1.x that allows in-memory compression using the I<deflate> interface |
1850 | provided by zlib. |
1851 | |
1852 | Here is a definition of the interface available: |
1853 | |
1854 | |
1855 | =head2 B<($d, $status) = deflateInit( [OPT] )> |
f4c6fd49 |
1856 | |
642e522c |
1857 | Initialises a deflation stream. |
1858 | |
1859 | It combines the features of the I<zlib> functions C<deflateInit>, |
1860 | C<deflateInit2> and C<deflateSetDictionary>. |
1861 | |
1862 | If successful, it will return the initialised deflation stream, C<$d> |
1863 | and C<$status> of C<Z_OK> in a list context. In scalar context it |
1864 | returns the deflation stream, C<$d>, only. |
1865 | |
1866 | If not successful, the returned deflation stream (C<$d>) will be |
1867 | I<undef> and C<$status> will hold the exact I<zlib> error code. |
bdd93743 |
1868 | |
642e522c |
1869 | The function optionally takes a number of named options specified as |
1870 | C<-Name=E<gt>value> pairs. This allows individual options to be |
1871 | tailored without having to specify them all in the parameter list. |
1872 | |
1873 | For backward compatibility, it is also possible to pass the parameters |
1874 | as a reference to a hash containing the name=>value pairs. |
1875 | |
1876 | The function takes one optional parameter, a reference to a hash. The |
1877 | contents of the hash allow the deflation interface to be tailored. |
1878 | |
1879 | Here is a list of the valid options: |
f4c6fd49 |
1880 | |
1881 | =over 5 |
1882 | |
642e522c |
1883 | =item B<-Level> |
f4c6fd49 |
1884 | |
642e522c |
1885 | Defines the compression level. Valid values are 0 through 9, |
1886 | C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, C<Z_BEST_COMPRESSION>, and |
1887 | C<Z_DEFAULT_COMPRESSION>. |
f4c6fd49 |
1888 | |
642e522c |
1889 | The default is C<-Level =E<gt>Z_DEFAULT_COMPRESSION>. |
f4c6fd49 |
1890 | |
642e522c |
1891 | =item B<-Method> |
f4c6fd49 |
1892 | |
642e522c |
1893 | Defines the compression method. The only valid value at present (and |
1894 | the default) is C<-Method =E<gt>Z_DEFLATED>. |
f4c6fd49 |
1895 | |
642e522c |
1896 | =item B<-WindowBits> |
f4c6fd49 |
1897 | |
642e522c |
1898 | For a definition of the meaning and valid values for C<WindowBits> |
1899 | refer to the I<zlib> documentation for I<deflateInit2>. |
f4c6fd49 |
1900 | |
642e522c |
1901 | Defaults to C<-WindowBits =E<gt>MAX_WBITS>. |
f4c6fd49 |
1902 | |
642e522c |
1903 | =item B<-MemLevel> |
f4c6fd49 |
1904 | |
642e522c |
1905 | For a definition of the meaning and valid values for C<MemLevel> |
1906 | refer to the I<zlib> documentation for I<deflateInit2>. |
bdd93743 |
1907 | |
642e522c |
1908 | Defaults to C<-MemLevel =E<gt>MAX_MEM_LEVEL>. |
f4c6fd49 |
1909 | |
642e522c |
1910 | =item B<-Strategy> |
f4c6fd49 |
1911 | |
642e522c |
1912 | Defines the strategy used to tune the compression. The valid values are |
1913 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED> and C<Z_HUFFMAN_ONLY>. |
f4c6fd49 |
1914 | |
642e522c |
1915 | The default is C<-Strategy =E<gt>Z_DEFAULT_STRATEGY>. |
f4c6fd49 |
1916 | |
642e522c |
1917 | =item B<-Dictionary> |
1918 | |
1919 | When a dictionary is specified I<Compress::Zlib> will automatically |
1920 | call C<deflateSetDictionary> directly after calling C<deflateInit>. The |
1921 | Adler32 value for the dictionary can be obtained by calling the method |
1922 | C<$d->dict_adler()>. |
f4c6fd49 |
1923 | |
642e522c |
1924 | The default is no dictionary. |
f4c6fd49 |
1925 | |
642e522c |
1926 | =item B<-Bufsize> |
f4c6fd49 |
1927 | |
642e522c |
1928 | Sets the initial size for the deflation buffer. If the buffer has to be |
1929 | reallocated to increase the size, it will grow in increments of |
1930 | C<Bufsize>. |
f4c6fd49 |
1931 | |
642e522c |
1932 | The default is 4096. |
f4c6fd49 |
1933 | |
642e522c |
1934 | =back |
f4c6fd49 |
1935 | |
642e522c |
1936 | Here is an example of using the C<deflateInit> optional parameter list |
1937 | to override the default buffer size and compression level. All other |
1938 | options will take their default values. |
f4c6fd49 |
1939 | |
642e522c |
1940 | deflateInit( -Bufsize => 300, |
1941 | -Level => Z_BEST_SPEED ) ; |
f4c6fd49 |
1942 | |
f4c6fd49 |
1943 | |
642e522c |
1944 | =head2 B<($out, $status) = $d-E<gt>deflate($buffer)> |
f4c6fd49 |
1945 | |
f4c6fd49 |
1946 | |
642e522c |
1947 | Deflates the contents of C<$buffer>. The buffer can either be a scalar |
1948 | or a scalar reference. When finished, C<$buffer> will be |
1949 | completely processed (assuming there were no errors). If the deflation |
1950 | was successful it returns the deflated output, C<$out>, and a status |
1951 | value, C<$status>, of C<Z_OK>. |
f4c6fd49 |
1952 | |
642e522c |
1953 | On error, C<$out> will be I<undef> and C<$status> will contain the |
1954 | I<zlib> error code. |
f4c6fd49 |
1955 | |
642e522c |
1956 | In a scalar context C<deflate> will return C<$out> only. |
f4c6fd49 |
1957 | |
642e522c |
1958 | As with the I<deflate> function in I<zlib>, it is not necessarily the |
1959 | case that any output will be produced by this method. So don't rely on |
1960 | the fact that C<$out> is empty for an error test. |
f4c6fd49 |
1961 | |
f4c6fd49 |
1962 | |
642e522c |
1963 | =head2 B<($out, $status) = $d-E<gt>flush([flush_type])> |
f4c6fd49 |
1964 | |
642e522c |
1965 | Typically used to finish the deflation. Any pending output will be |
1966 | returned via C<$out>. |
1967 | C<$status> will have a value C<Z_OK> if successful. |
f4c6fd49 |
1968 | |
642e522c |
1969 | In a scalar context C<flush> will return C<$out> only. |
f4c6fd49 |
1970 | |
642e522c |
1971 | Note that flushing can seriously degrade the compression ratio, so it |
1972 | should only be used to terminate a decompression (using C<Z_FINISH>) or |
1973 | when you want to create a I<full flush point> (using C<Z_FULL_FLUSH>). |
f4c6fd49 |
1974 | |
642e522c |
1975 | By default the C<flush_type> used is C<Z_FINISH>. Other valid values |
1976 | for C<flush_type> are C<Z_NO_FLUSH>, C<Z_PARTIAL_FLUSH>, C<Z_SYNC_FLUSH> |
1977 | and C<Z_FULL_FLUSH>. It is strongly recommended that you only set the |
1978 | C<flush_type> parameter if you fully understand the implications of |
1979 | what it does. See the C<zlib> documentation for details. |
f4c6fd49 |
1980 | |
642e522c |
1981 | =head2 B<$status = $d-E<gt>deflateParams([OPT])> |
f4c6fd49 |
1982 | |
642e522c |
1983 | Change settings for the deflate stream C<$d>. |
f4c6fd49 |
1984 | |
1985 | The list of the valid options is shown below. Options not specified |
1986 | will remain unchanged. |
1987 | |
f4c6fd49 |
1988 | =over 5 |
1989 | |
642e522c |
1990 | =item B<-Level> |
f4c6fd49 |
1991 | |
1992 | Defines the compression level. Valid values are 0 through 9, |
1993 | C<Z_NO_COMPRESSION>, C<Z_BEST_SPEED>, C<Z_BEST_COMPRESSION>, and |
1994 | C<Z_DEFAULT_COMPRESSION>. |
1995 | |
642e522c |
1996 | =item B<-Strategy> |
f4c6fd49 |
1997 | |
1998 | Defines the strategy used to tune the compression. The valid values are |
1999 | C<Z_DEFAULT_STRATEGY>, C<Z_FILTERED> and C<Z_HUFFMAN_ONLY>. |
2000 | |
2001 | =back |
2002 | |
642e522c |
2003 | =head2 B<$d-E<gt>dict_adler()> |
f4c6fd49 |
2004 | |
642e522c |
2005 | Returns the adler32 value for the dictionary. |
f4c6fd49 |
2006 | |
642e522c |
2007 | =head2 B<$d-E<gt>msg()> |
f4c6fd49 |
2008 | |
642e522c |
2009 | Returns the last error message generated by zlib. |
f4c6fd49 |
2010 | |
642e522c |
2011 | =head2 B<$d-E<gt>total_in()> |
f4c6fd49 |
2012 | |
642e522c |
2013 | Returns the total number of bytes uncompressed bytes input to deflate. |
f4c6fd49 |
2014 | |
642e522c |
2015 | =head2 B<$d-E<gt>total_out()> |
f4c6fd49 |
2016 | |
642e522c |
2017 | Returns the total number of compressed bytes output from deflate. |
f4c6fd49 |
2018 | |
642e522c |
2019 | =head2 Example |
f4c6fd49 |
2020 | |
f4c6fd49 |
2021 | |
642e522c |
2022 | Here is a trivial example of using C<deflate>. It simply reads standard |
2023 | input, deflates it and writes it to standard output. |
f4c6fd49 |
2024 | |
2025 | use strict ; |
2026 | use warnings ; |
642e522c |
2027 | |
f4c6fd49 |
2028 | use Compress::Zlib ; |
f4c6fd49 |
2029 | |
642e522c |
2030 | binmode STDIN; |
2031 | binmode STDOUT; |
2032 | my $x = deflateInit() |
2033 | or die "Cannot create a deflation stream\n" ; |
f4c6fd49 |
2034 | |
642e522c |
2035 | my ($output, $status) ; |
2036 | while (<>) |
2037 | { |
2038 | ($output, $status) = $x->deflate($_) ; |
f4c6fd49 |
2039 | |
642e522c |
2040 | $status == Z_OK |
2041 | or die "deflation failed\n" ; |
f4c6fd49 |
2042 | |
642e522c |
2043 | print $output ; |
f4c6fd49 |
2044 | } |
f4c6fd49 |
2045 | |
642e522c |
2046 | ($output, $status) = $x->flush() ; |
f4c6fd49 |
2047 | |
642e522c |
2048 | $status == Z_OK |
2049 | or die "deflation failed\n" ; |
f4c6fd49 |
2050 | |
642e522c |
2051 | print $output ; |
f4c6fd49 |
2052 | |
642e522c |
2053 | =head1 Compress::Zlib 1.x Inflate Interface |
f4c6fd49 |
2054 | |
642e522c |
2055 | This section defines the interface available in C<Compress::Zlib> version |
2056 | 1.x that allows in-memory uncompression using the I<deflate> interface |
2057 | provided by zlib. |
f4c6fd49 |
2058 | |
642e522c |
2059 | Here is a definition of the interface: |
f4c6fd49 |
2060 | |
f4c6fd49 |
2061 | |
642e522c |
2062 | =head2 B<($i, $status) = inflateInit()> |
f4c6fd49 |
2063 | |
642e522c |
2064 | Initialises an inflation stream. |
f4c6fd49 |
2065 | |
642e522c |
2066 | In a list context it returns the inflation stream, C<$i>, and the |
2067 | I<zlib> status code (C<$status>). In a scalar context it returns the |
2068 | inflation stream only. |
f4c6fd49 |
2069 | |
642e522c |
2070 | If successful, C<$i> will hold the inflation stream and C<$status> will |
2071 | be C<Z_OK>. |
f4c6fd49 |
2072 | |
642e522c |
2073 | If not successful, C<$i> will be I<undef> and C<$status> will hold the |
2074 | I<zlib> error code. |
f4c6fd49 |
2075 | |
642e522c |
2076 | The function optionally takes a number of named options specified as |
2077 | C<-Name=E<gt>value> pairs. This allows individual options to be |
2078 | tailored without having to specify them all in the parameter list. |
2079 | |
2080 | For backward compatibility, it is also possible to pass the parameters |
2081 | as a reference to a hash containing the name=>value pairs. |
2082 | |
2083 | The function takes one optional parameter, a reference to a hash. The |
2084 | contents of the hash allow the deflation interface to be tailored. |
2085 | |
2086 | Here is a list of the valid options: |
f4c6fd49 |
2087 | |
642e522c |
2088 | =over 5 |
f4c6fd49 |
2089 | |
642e522c |
2090 | =item B<-WindowBits> |
f4c6fd49 |
2091 | |
642e522c |
2092 | For a definition of the meaning and valid values for C<WindowBits> |
2093 | refer to the I<zlib> documentation for I<inflateInit2>. |
f4c6fd49 |
2094 | |
642e522c |
2095 | Defaults to C<-WindowBits =E<gt>MAX_WBITS>. |
f4c6fd49 |
2096 | |
642e522c |
2097 | =item B<-Bufsize> |
f4c6fd49 |
2098 | |
642e522c |
2099 | Sets the initial size for the inflation buffer. If the buffer has to be |
2100 | reallocated to increase the size, it will grow in increments of |
2101 | C<Bufsize>. |
f4c6fd49 |
2102 | |
642e522c |
2103 | Default is 4096. |
5993747c |
2104 | |
642e522c |
2105 | =item B<-Dictionary> |
5993747c |
2106 | |
642e522c |
2107 | The default is no dictionary. |
5993747c |
2108 | |
642e522c |
2109 | =back |
5993747c |
2110 | |
642e522c |
2111 | Here is an example of using the C<inflateInit> optional parameter to |
2112 | override the default buffer size. |
5993747c |
2113 | |
642e522c |
2114 | inflateInit( -Bufsize => 300 ) ; |
5993747c |
2115 | |
642e522c |
2116 | =head2 B<($out, $status) = $i-E<gt>inflate($buffer)> |
5993747c |
2117 | |
642e522c |
2118 | Inflates the complete contents of C<$buffer>. The buffer can either be |
2119 | a scalar or a scalar reference. |
5993747c |
2120 | |
642e522c |
2121 | Returns C<Z_OK> if successful and C<Z_STREAM_END> if the end of the |
2122 | compressed data has been successfully reached. |
2123 | If not successful, C<$out> will be I<undef> and C<$status> will hold |
2124 | the I<zlib> error code. |
5993747c |
2125 | |
642e522c |
2126 | The C<$buffer> parameter is modified by C<inflate>. On completion it |
2127 | will contain what remains of the input buffer after inflation. This |
2128 | means that C<$buffer> will be an empty string when the return status is |
2129 | C<Z_OK>. When the return status is C<Z_STREAM_END> the C<$buffer> |
2130 | parameter will contains what (if anything) was stored in the input |
2131 | buffer after the deflated data stream. |
5993747c |
2132 | |
642e522c |
2133 | This feature is useful when processing a file format that encapsulates |
2134 | a compressed data stream (e.g. gzip, zip). |
5993747c |
2135 | |
642e522c |
2136 | =head2 B<$status = $i-E<gt>inflateSync($buffer)> |
5993747c |
2137 | |
642e522c |
2138 | Scans C<$buffer> until it reaches either a I<full flush point> or the |
2139 | end of the buffer. |
5993747c |
2140 | |
642e522c |
2141 | If a I<full flush point> is found, C<Z_OK> is returned and C<$buffer> |
2142 | will be have all data up to the flush point removed. This can then be |
2143 | passed to the C<deflate> method. |
5993747c |
2144 | |
642e522c |
2145 | Any other return code means that a flush point was not found. If more |
2146 | data is available, C<inflateSync> can be called repeatedly with more |
2147 | compressed data until the flush point is found. |
5993747c |
2148 | |
5993747c |
2149 | |
642e522c |
2150 | =head2 B<$i-E<gt>dict_adler()> |
5993747c |
2151 | |
642e522c |
2152 | Returns the adler32 value for the dictionary. |
5993747c |
2153 | |
642e522c |
2154 | =head2 B<$i-E<gt>msg()> |
5993747c |
2155 | |
642e522c |
2156 | Returns the last error message generated by zlib. |
5993747c |
2157 | |
642e522c |
2158 | =head2 B<$i-E<gt>total_in()> |
5993747c |
2159 | |
642e522c |
2160 | Returns the total number of bytes compressed bytes input to inflate. |
f4c6fd49 |
2161 | |
642e522c |
2162 | =head2 B<$i-E<gt>total_out()> |
f4c6fd49 |
2163 | |
642e522c |
2164 | Returns the total number of uncompressed bytes output from inflate. |
f4c6fd49 |
2165 | |
642e522c |
2166 | =head2 Example |
f4c6fd49 |
2167 | |
642e522c |
2168 | Here is an example of using C<inflate>. |
f4c6fd49 |
2169 | |
642e522c |
2170 | use strict ; |
2171 | use warnings ; |
2172 | |
2173 | use Compress::Zlib ; |
2174 | |
2175 | my $x = inflateInit() |
2176 | or die "Cannot create a inflation stream\n" ; |
2177 | |
2178 | my $input = '' ; |
2179 | binmode STDIN; |
2180 | binmode STDOUT; |
2181 | |
2182 | my ($output, $status) ; |
2183 | while (read(STDIN, $input, 4096)) |
2184 | { |
2185 | ($output, $status) = $x->inflate(\$input) ; |
2186 | |
2187 | print $output |
2188 | if $status == Z_OK or $status == Z_STREAM_END ; |
2189 | |
2190 | last if $status != Z_OK ; |
2191 | } |
2192 | |
2193 | die "inflation failed\n" |
2194 | unless $status == Z_STREAM_END ; |
f4c6fd49 |
2195 | |
642e522c |
2196 | =head1 ACCESSING ZIP FILES |
f4c6fd49 |
2197 | |
642e522c |
2198 | Although it is possible (with some effort on your part) to use this |
2199 | module to access .zip files, there is a module on CPAN that will do all |
2200 | the hard work for you. Check out the C<Archive::Zip> module on CPAN at |
f4c6fd49 |
2201 | |
642e522c |
2202 | http://www.cpan.org/modules/by-module/Archive/Archive-Zip-*.tar.gz |
f4c6fd49 |
2203 | |
f4c6fd49 |
2204 | |
2205 | =head1 CONSTANTS |
2206 | |
2207 | All the I<zlib> constants are automatically imported when you make use |
2208 | of I<Compress::Zlib>. |
2209 | |
642e522c |
2210 | |
2211 | =head1 SEE ALSO |
2212 | |
2213 | L<IO::Compress::Gzip>, L<IO::Uncompress::Gunzip>, L<IO::Compress::Deflate>, L<IO::Uncompress::Inflate>, L<IO::Compress::RawDeflate>, L<IO::Uncompress::RawInflate>, L<IO::Uncompress::AnyInflate> |
2214 | |
2215 | L<Compress::Zlib::FAQ|Compress::Zlib::FAQ> |
2216 | |
2217 | L<File::GlobMapper|File::GlobMapper>, L<Archive::Tar|Archive::Zip>, |
2218 | L<IO::Zlib|IO::Zlib> |
2219 | |
2220 | For RFC 1950, 1951 and 1952 see |
2221 | F<http://www.faqs.org/rfcs/rfc1950.html>, |
2222 | F<http://www.faqs.org/rfcs/rfc1951.html> and |
2223 | F<http://www.faqs.org/rfcs/rfc1952.html> |
2224 | |
2225 | The primary site for the gzip program is F<http://www.gzip.org>. |
2226 | |
f4c6fd49 |
2227 | =head1 AUTHOR |
2228 | |
2229 | The I<Compress::Zlib> module was written by Paul Marquess, |
2230 | F<pmqs@cpan.org>. The latest copy of the module can be |
2231 | found on CPAN in F<modules/by-module/Compress/Compress-Zlib-x.x.tar.gz>. |
2232 | |
642e522c |
2233 | The I<zlib> compression library was written by Jean-loup Gailly |
2234 | F<gzip@prep.ai.mit.edu> and Mark Adler F<madler@alumni.caltech.edu>. |
2235 | |
f4c6fd49 |
2236 | The primary site for the I<zlib> compression library is |
2237 | F<http://www.zlib.org>. |
2238 | |
2239 | =head1 MODIFICATION HISTORY |
2240 | |
2241 | See the Changes file. |
642e522c |
2242 | |
2243 | =head1 COPYRIGHT AND LICENSE |
2244 | |
2245 | |
2246 | Copyright (c) 1995-2005 Paul Marquess. All rights reserved. |
2247 | This program is free software; you can redistribute it and/or |
2248 | modify it under the same terms as Perl itself. |
2249 | |
2250 | |
2251 | |
2252 | |
2253 | |