summaryrefslogtreecommitdiff
path: root/zipstream.php
blob: fdf923c5e09a1501c9a3dfbc3d7ba6e35ed30fe8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
<?php

##########################################################################
# ZipStream - Streamed, dynamically generated zip archives.              #
# by Paul Duncan <pabs@pablotron.org>                                    #
#                                                                        #
# Copyright (C) 2007-2009 Paul Duncan <pabs@pablotron.org>               #
#                                                                        #
# Permission is hereby granted, free of charge, to any person obtaining  #
# a copy of this software and associated documentation files (the        #
# "Software"), to deal in the Software without restriction, including    #
# without limitation the rights to use, copy, modify, merge, publish,    #
# distribute, sublicense, and/or sell copies of the Software, and to     #
# permit persons to whom the Software is furnished to do so, subject to  #
# the following conditions:                                              #
#                                                                        #
# The above copyright notice and this permission notice shall be         #
# included in all copies of the Software, its documentation and          #
# marketing & publicity materials, and acknowledgment shall be given in  #
# the documentation, materials and software packages that this Software  #
# was used.                                                              #
#                                                                        #
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        #
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     #
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. #
# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR      #
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,  #
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR  #
# OTHER DEALINGS IN THE SOFTWARE.                                        #
##########################################################################

#
# ZipStream - Streamed, dynamically generated zip archives.
# by Paul Duncan <pabs@pablotron.org>
#
# Requirements:
#
# * PHP version 5.1.2 or newer.
#
# Usage:
#
# Streaming zip archives is a simple, three-step process:
#
# 1.  Create the zip stream:
#
#     $zip = new ZipStream('example.zip');
#
# 2.  Add one or more files to the archive:
#
#     # add first file
#     $data = file_get_contents('some_file.gif');
#     $zip->add_file('some_file.gif', $data);
#
#     # add second file
#     $data = file_get_contents('some_file.gif');
#     $zip->add_file('another_file.png', $data);
#
# 3.  Finish the zip stream:
#
#     $zip->finish();
#
# You can also add an archive comment, add comments to individual files,
# and adjust the timestamp of files.  See the API documentation for each
# method below for additional information.
#
# Example:
#
#   # create a new zip stream object
#   $zip = new ZipStream('some_files.zip');
#
#   # list of local files
#   $files = array('foo.txt', 'bar.jpg');
#
#   # read and add each file to the archive
#   foreach ($files as $path)
#     $zip->add_file($path, file_get_contents($path));
# 
#   # write archive footer to stream
#   $zip->finish();
#
class ZipStream {
  const VERSION = '0.2.0';

  var $opt = array(),
      $files = array(),
      $cdr_ofs = 0,
      $ofs = 0; 

  #
  # Create a new ZipStream object.
  #
  # Parameters:
  #
  #   $name - Name of output file (optional).
  #   $opt  - Hash of archive options (optional, see "Archive Options"
  #           below).
  #
  # Archive Options:
  #
  #   comment             - Comment for this archive.
  #   content_type        - HTTP Content-Type.  Defaults to 'application/x-zip'.
  #   content_disposition - HTTP Content-Disposition.  Defaults to 
  #                         'attachment; filename=\"FILENAME\"', where
  #                         FILENAME is the specified filename.
  #   large_file_size     - Size, in bytes, of the largest file to try
  #                         and load into memory (used by
  #                         add_file_from_path()).  Large files may also
  #                         be compressed differently; see the
  #                         'large_file_method' option.
  #   large_file_method   - How to handle large files.  Legal values are
  #                         'store' (the default), or 'deflate'.  Store
  #                         sends the file raw and is significantly
  #                         faster, while 'deflate' compresses the file
  #                         and is much, much slower.  Note that deflate
  #                         must compress the file twice and extremely
  #                         slow.
  #   send_http_headers   - Boolean indicating whether or not to send
  #                         the HTTP headers for this file.
  #
  # Note that content_type and content_disposition do nothing if you are
  # not sending HTTP headers.
  #
  # Large File Support:
  #
  # By default, the method add_file_from_path() will send send files
  # larger than 20 megabytes along raw rather than attempting to
  # compress them.  You can change both the maximum size and the
  # compression behavior using the large_file_* options above, with the
  # following caveats:
  #
  # * For "small" files (e.g. files smaller than large_file_size), the
  #   memory use can be up to twice that of the actual file.  In other
  #   words, adding a 10 megabyte file to the archive could potentially
  #   occupty 20 megabytes of memory.
  #
  # * Enabling compression on large files (e.g. files larger than
  #   large_file_size) is extremely slow, because ZipStream has to pass
  #   over the large file once to calculate header information, and then
  #   again to compress and send the actual data.
  #
  # Examples:
  #
  #   # create a new zip file named 'foo.zip'
  #   $zip = new ZipStream('foo.zip');
  #
  #   # create a new zip file named 'bar.zip' with a comment
  #   $zip = new ZipStream('bar.zip', array(
  #     'comment' => 'this is a comment for the zip file.',
  #   ));
  #
  # Notes:
  #
  # If you do not set a filename, then this library _DOES NOT_ send HTTP
  # headers by default.  This behavior is to allow software to send its
  # own headers (including the filename), and still use this library.
  #
  function __construct($name = null, $opt = array()) {
    # save options
    $this->opt = $opt;

    # set large file defaults: size = 20 megabytes, method = store
    if (!$this->opt['large_file_size'])
      $this->opt['large_file_size'] = 20 * 1024 * 1024;
    if (!$this->opt['large_file_method'])
      $this->opt['large_file_method'] = 'store';

    $this->output_name = $name;
    if ($name || $opt['send_http_headers'])
      $this->need_headers = true; 
  }

  #
  # add_file - add a file to the archive
  #
  # Parameters:
  #   
  #  $name - path of file in archive (including directory).
  #  $data - contents of file
  #  $opt  - Hash of options for file (optional, see "File Options"
  #          below).  
  #
  # File Options: 
  #  time     - Last-modified timestamp (seconds since the epoch) of
  #             this file.  Defaults to the current time.
  #  comment  - Comment related to this file.
  #
  # Examples:
  #
  #   # add a file named 'foo.txt'
  #   $data = file_get_contents('foo.txt');
  #   $zip->add_file('foo.txt', $data);
  # 
  #   # add a file named 'bar.jpg' with a comment and a last-modified
  #   # time of two hours ago
  #   $data = file_get_contents('bar.jpg');
  #   $zip->add_file('bar.jpg', $data, array(
  #     'time'    => time() - 2 * 3600,
  #     'comment' => 'this is a comment about bar.jpg',
  #   ));
  # 
  function add_file($name, $data, $opt = array()) {
    # compress data
    $zdata = gzdeflate($data);

    # calculate header attributes
    $crc  = crc32($data);
    $zlen = strlen($zdata);
    $len  = strlen($data);
    $meth = 0x08;

    # send file header
    $this->add_file_header($name, $opt, $meth, $crc, $zlen, $len);

    # print data
    $this->send($zdata);
  }

  #
  # add_file_from_path - add a file at path to the archive.
  #
  # Note that large files may be compresed differently than smaller
  # files; see the "Large File Support" section above for more
  # information.
  #
  # Parameters:
  #   
  #  $name - name of file in archive (including directory path).
  #  $path - path to file on disk (note: paths should be encoded using
  #          UNIX-style forward slashes -- e.g '/path/to/some/file').
  #  $opt  - Hash of options for file (optional, see "File Options"
  #          below).  
  #
  # File Options: 
  #  time     - Last-modified timestamp (seconds since the epoch) of
  #             this file.  Defaults to the current time.
  #  comment  - Comment related to this file.
  #
  # Examples:
  #
  #   # add a file named 'foo.txt' from the local file '/tmp/foo.txt'
  #   $zip->add_file_from_path('foo.txt', '/tmp/foo.txt');
  # 
  #   # add a file named 'bigfile.rar' from the local file
  #   # '/usr/share/bigfile.rar' with a comment and a last-modified
  #   # time of two hours ago
  #   $path = '/usr/share/bigfile.rar';
  #   $zip->add_file_from_path('bigfile.rar', $path, array(
  #     'time'    => time() - 2 * 3600,
  #     'comment' => 'this is a comment about bar.jpg',
  #   ));
  # 
  function add_file_from_path($name, $path, $opt = array()) {
    if ($this->is_large_file($path)) {
      # file is too large to be read into memory; add progressively
      $this->add_large_file($name, $path, $opt);
    } else {
      # file is small enough to read into memory; read file contents and
      # handle with add_file()
      $data = file_get_contents($path);
      $this->add_file($name, $data, $opt);
    }
  }

  #
  # finish - Write zip footer to stream.
  #
  # Example:
  #
  #   # add a list of files to the archive
  #   $files = array('foo.txt', 'bar.jpg');
  #   foreach ($files as $path)
  #     $zip->add_file($path, file_get_contents($path));
  # 
  #   # write footer to stream
  #   $zip->finish();
  # 
  function finish() {
    # add trailing cdr record
    $this->add_cdr($this->opt);
    $this->clear();
  }

  ###################
  # PRIVATE METHODS #
  ###################

  #
  # Create and send zip header for this file.
  #
  private function add_file_header($name, $opt, $meth, $crc, $zlen, $len) {
    # strip leading slashes from file name
    # (fixes bug in windows archive viewer)
    $name = preg_replace('/^\\/+/', '', $name);

    # calculate name length
    $nlen = strlen($name);

    # create dos timestamp
    $opt['time'] = $opt['time'] ? $opt['time'] : time();
    $dts = $this->dostime($opt['time']);

    # build file header
    $fields = array(            # (from V.A of APPNOTE.TXT)
      array('V', 0x04034b50),     # local file header signature
      array('v', (6 << 8) + 3),   # version needed to extract
      array('v', 0x00),           # general purpose bit flag
      array('v', $meth),          # compresion method (deflate or store)
      array('V', $dts),           # dos timestamp
      array('V', $crc),           # crc32 of data
      array('V', $zlen),          # compressed data length
      array('V', $len),           # uncompressed data length
      array('v', $nlen),          # filename length
      array('v', 0),              # extra data len
    );

    # pack fields and calculate "total" length
    $ret = $this->pack_fields($fields);
    $cdr_len = strlen($ret) + $nlen + $zlen;

    # print header and filename
    $this->send($ret . $name);

    # add to central directory record and increment offset
    $this->add_to_cdr($name, $opt, $meth, $crc, $zlen, $len, $cdr_len);
  }

  #
  # Add a large file from the given path.
  #
  private function add_large_file($name, $path, $opt = array()) {
    $st = stat($path);
    $block_size = 1048576; # process in 1 megabyte chunks
    $algo = 'crc32b';

    # calculate header attributes
    $zlen = $len = $st['size'];

    $meth_str = $this->opt['large_file_method'];
    if ($meth_str == 'store') {
      # store method
      $meth = 0x00;
      $crc  = unpack('V', hash_file($algo, $path, true));
      $crc = $crc[1];
    } elseif ($meth_str == 'deflate') {
      # deflate method
      $meth = 0x08;

      # open file, calculate crc and compressed file length
      $fh = fopen($path, 'rb');
      $hash_ctx = hash_init($algo);
      $zlen = 0;

      # read each block, update crc and zlen
      while ($data = fgets($fh, $block_size)) {
        hash_update($hash_ctx, $data);
        $data = gzdeflate($data);
        $zlen += strlen($data);
      }

      # close file and finalize crc
      fclose($fh);
      $crc = unpack('V', hash_final($hash_ctx, true));
      $crc = $crc[1];
    } else {
      die("unknown large_file_method: $meth_str");
    }

    # send file header
    $this->add_file_header($name, $opt, $meth, $crc, $zlen, $len);

    # open input file
    $fh = fopen($path, 'rb');

    # send file blocks
    while ($data = fgets($fh, $block_size)) {
      if ($meth_str == 'deflate') 
        $data = gzdeflate($data);

      # send data
      $this->send($data);
    }

    # close input file
    fclose($fh);
  }

  #
  # Is this file larger than large_file_size?
  #
  function is_large_file($path) {
    $st = stat($path);
    return ($this->opt['large_file_size'] > 0) && 
           ($st['size'] > $this->opt['large_file_size']);
  }

  #
  # Save file attributes for trailing CDR record.
  #
  private function add_to_cdr($name, $opt, $meth, $crc, $zlen, $len, $rec_len) {
    $this->files[] = array($name, $opt, $meth, $crc, $zlen, $len, $this->ofs);
    $this->ofs += $rec_len;
  }

  #
  # Send CDR record for specified file.
  #
  private function add_cdr_file($args) {
    list ($name, $opt, $meth, $crc, $zlen, $len, $ofs) = $args;

    # get attributes
    $comment = $opt['comment'] ? $opt['comment'] : '';

    # get dos timestamp
    $dts = $this->dostime($opt['time']);

    $fields = array(                  # (from V,F of APPNOTE.TXT)
      array('V', 0x02014b50),           # central file header signature
      array('v', (6 << 8) + 3),         # version made by
      array('v', (6 << 8) + 3),         # version needed to extract
      array('v', 0x00),                 # general purpose bit flag
      array('v', $meth),                # compresion method (deflate or store)
      array('V', $dts),                 # dos timestamp
      array('V', $crc),                 # crc32 of data
      array('V', $zlen),                # compressed data length
      array('V', $len),                 # uncompressed data length
      array('v', strlen($name)),        # filename length
      array('v', 0),                    # extra data len
      array('v', strlen($comment)),     # file comment length
      array('v', 0),                    # disk number start
      array('v', 0),                    # internal file attributes
      array('V', 32),                   # external file attributes
      array('V', $ofs),                 # relative offset of local header
    );

    # pack fields, then append name and comment
    $ret = $this->pack_fields($fields) . $name . $comment;

    $this->send($ret);

    # increment cdr offset
    $this->cdr_ofs += strlen($ret);
  }

  #
  # Send CDR EOF (Central Directory Record End-of-File) record.
  #
  private function add_cdr_eof($opt = null) {
    $num = count($this->files);
    $cdr_len = $this->cdr_ofs;
    $cdr_ofs = $this->ofs;

    # grab comment (if specified)
    $comment = '';
    if ($opt && $opt['comment'])
      $comment = $opt['comment'];

    $fields = array(                # (from V,F of APPNOTE.TXT)
      array('V', 0x06054b50),         # end of central file header signature
      array('v', 0x00),               # this disk number
      array('v', 0x00),               # number of disk with cdr
      array('v', $num),               # number of entries in the cdr on this disk
      array('v', $num),               # number of entries in the cdr
      array('V', $cdr_len),           # cdr size
      array('V', $cdr_ofs),           # cdr ofs
      array('v', strlen($comment)),   # zip file comment length
    );

    $ret = $this->pack_fields($fields) . $comment;
    $this->send($ret);
  }

  #
  # Add CDR (Central Directory Record) footer.
  #
  private function add_cdr($opt = null) {
    foreach ($this->files as $file)
      $this->add_cdr_file($file);
    $this->add_cdr_eof($opt);
  }

  #
  # Clear all internal variables.  Note that the stream object is not
  # usable after this.
  #
  function clear() {
    $this->files = array();
    $this->ofs = 0;
    $this->cdr_ofs = 0;
    $this->opt = array();
  }

  ###########################
  # PRIVATE UTILITY METHODS #
  ###########################

  #
  # Send HTTP headers for this stream.
  #
  private function send_http_headers() {
    # grab options
    $opt = $this->opt;
    
    # grab content type from options
    $content_type = 'application/x-zip';
    if ($opt['content_type'])
      $content_type = $this->opt['content_type'];

    # grab content disposition 
    $disposition = 'attachment';
    if ($opt['content_disposition'])
      $disposition = $opt['content_disposition'];

    if ($this->output_name) 
      $disposition .= "; filename=\"{$this->output_name}\"";

    $headers = array(
      'Content-Type'              => $content_type,
      'Content-Disposition'       => $disposition,
      'Pragma'                    => 'public',
      'Cache-Control'             => 'public, must-revalidate',
      'Content-Transfer-Encoding' => 'binary',
    );

    foreach ($headers as $key => $val)
      header("$key: $val");
  }

  #
  # Send string, sending HTTP headers if necessary.
  #
  private function send($str) {
    if ($this->need_headers)
      $this->send_http_headers();
    $this->need_headers = false;

    echo $str;
  }

  #
  # Convert a UNIX timestamp to a DOS timestamp.
  #
  function dostime($when = 0) {
    # get date array for timestamp
    $d = getdate($when);

    # set lower-bound on dates
    if ($d['year'] < 1980) {
      $d = array('year' => 1980, 'mon' => 1, 'mday' => 1, 
                 'hours' => 0, 'minutes' => 0, 'seconds' => 0);
    }

    # remove extra years from 1980
    $d['year'] -= 1980;

    # return date string
    return ($d['year'] << 25) | ($d['mon'] << 21) | ($d['mday'] << 16) |
           ($d['hours'] << 11) | ($d['minutes'] << 5) | ($d['seconds'] >> 1);
  }

  #
  # Create a format string and argument list for pack(), then call
  # pack() and return the result.
  #
  function pack_fields($fields) {
    list ($fmt, $args) = array('', array());

    # populate format string and argument list
    foreach ($fields as $field) {
      $fmt .= $field[0];
      $args[] = $field[1];
    }

    # prepend format string to argument list
    array_unshift($args, $fmt);

    # build output string from header and compressed data
    return call_user_func_array('pack', $args);
  }
};

?>