Passed
Push — php8 ( d3508b...c61853 )
by Konrad
05:01 queued 02:47
created

RawDataParser::decodeXref()   C

Complexity

Conditions 15
Paths 134

Size

Total Lines 64
Code Lines 37

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 34
CRAP Score 15.0386

Importance

Changes 4
Bugs 2 Features 1
Metric Value
cc 15
eloc 37
c 4
b 2
f 1
nc 134
nop 3
dl 0
loc 64
ccs 34
cts 36
cp 0.9444
crap 15.0386
rs 5.6333

How to fix   Long Method    Complexity   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

1
<?php
2
3
/**
4
 * This file is based on code of tecnickcom/TCPDF PDF library.
5
 *
6
 * Original author Nicola Asuni ([email protected]) and
7
 * contributors (https://github.com/tecnickcom/TCPDF/graphs/contributors).
8
 *
9
 * @see https://github.com/tecnickcom/TCPDF
10
 *
11
 * Original code was licensed on the terms of the LGPL v3.
12
 *
13
 * ------------------------------------------------------------------------------
14
 *
15
 * @file This file is part of the PdfParser library.
16
 *
17
 * @author  Konrad Abicht <[email protected]>
18
 * @date    2020-01-06
19
 *
20
 * @license LGPLv3
21
 * @url     <https://github.com/smalot/pdfparser>
22
 *
23
 *  PdfParser is a pdf library written in PHP, extraction oriented.
24
 *  Copyright (C) 2017 - Sébastien MALOT <[email protected]>
25
 *
26
 *  This program is free software: you can redistribute it and/or modify
27
 *  it under the terms of the GNU Lesser General Public License as published by
28
 *  the Free Software Foundation, either version 3 of the License, or
29
 *  (at your option) any later version.
30
 *
31
 *  This program is distributed in the hope that it will be useful,
32
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
33
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
34
 *  GNU Lesser General Public License for more details.
35
 *
36
 *  You should have received a copy of the GNU Lesser General Public License
37
 *  along with this program.
38
 *  If not, see <http://www.pdfparser.org/sites/default/LICENSE.txt>.
39
 */
40
41
namespace Smalot\PdfParser\RawData;
42
43
use Exception;
44
45
class RawDataParser
46
{
47
    /**
48
     * Configuration array.
49
     */
50
    protected $cfg = [
51
        // if `true` ignore filter decoding errors
52
        'ignore_filter_decoding_errors' => true,
53
        // if `true` ignore missing filter decoding errors
54
        'ignore_missing_filter_decoders' => true,
55
    ];
56
57
    protected $filterHelper;
58
    protected $objects;
59
60
    /**
61
     * @param array $cfg Configuration array, default is []
62
     */
63 30
    public function __construct($cfg = [])
64
    {
65
        // merge given array with default values
66 30
        $this->cfg = array_merge($this->cfg, $cfg);
67
68 30
        $this->filterHelper = new FilterHelper();
69 30
    }
70
71
    /**
72
     * Decode the specified stream.
73
     *
74
     * @param string $pdfData PDF data
75
     * @param array  $xref
76
     * @param array  $sdic    Stream's dictionary array
77
     * @param string $stream  Stream to decode
78
     *
79
     * @return array containing decoded stream data and remaining filters
80
     */
81 26
    protected function decodeStream($pdfData, $xref, $sdic, $stream)
82
    {
83
        // get stream length and filters
84 26
        $slength = \strlen($stream);
85 26
        if ($slength <= 0) {
86
            return ['', []];
87
        }
88 26
        $filters = [];
89 26
        foreach ($sdic as $k => $v) {
90 26
            if ('/' == $v[0]) {
91 26
                if (('Length' == $v[1]) && (isset($sdic[($k + 1)])) && ('numeric' == $sdic[($k + 1)][0])) {
92
                    // get declared stream length
93 25
                    $declength = (int) ($sdic[($k + 1)][1]);
94 25
                    if ($declength < $slength) {
95 25
                        $stream = substr($stream, 0, $declength);
96 25
                        $slength = $declength;
97
                    }
98 26
                } elseif (('Filter' == $v[1]) && (isset($sdic[($k + 1)]))) {
99
                    // resolve indirect object
100 26
                    $objval = $this->getObjectVal($pdfData, $xref, $sdic[($k + 1)]);
101 26
                    if ('/' == $objval[0]) {
102
                        // single filter
103 26
                        $filters[] = $objval[1];
104 1
                    } elseif ('[' == $objval[0]) {
105
                        // array of filters
106 1
                        foreach ($objval[1] as $flt) {
107 1
                            if ('/' == $flt[0]) {
108 1
                                $filters[] = $flt[1];
109
                            }
110
                        }
111
                    }
112
                }
113
            }
114
        }
115
116
        // decode the stream
117 26
        $remaining_filters = [];
118 26
        foreach ($filters as $filter) {
119 26
            if (\in_array($filter, $this->filterHelper->getAvailableFilters())) {
120
                try {
121 26
                    $stream = $this->filterHelper->decodeFilter($filter, $stream);
122 1
                } catch (Exception $e) {
123 1
                    $emsg = $e->getMessage();
124 1
                    if ((('~' == $emsg[0]) && !$this->cfg['ignore_missing_filter_decoders'])
125 1
                        || (('~' != $emsg[0]) && !$this->cfg['ignore_filter_decoding_errors'])
126
                    ) {
127 26
                        throw new Exception($e->getMessage());
128
                    }
129
                }
130
            } else {
131
                // add missing filter to array
132 4
                $remaining_filters[] = $filter;
133
            }
134
        }
135
136 26
        return [$stream, $remaining_filters];
137
    }
138
139
    /**
140
     * Decode the Cross-Reference section
141
     *
142
     * @param string $pdfData   PDF data
143
     * @param int    $startxref Offset at which the xref section starts (position of the 'xref' keyword)
144
     * @param array  $xref      Previous xref array (if any)
145
     *
146
     * @return array containing xref and trailer data
147
     */
148 22
    protected function decodeXref($pdfData, $startxref, $xref = [])
149
    {
150 22
        $startxref += 4; // 4 is the length of the word 'xref'
151
        // skip initial white space chars: \x00 null (NUL), \x09 horizontal tab (HT), \x0A line feed (LF), \x0C form feed (FF), \x0D carriage return (CR), \x20 space (SP)
152 22
        $offset = $startxref + strspn($pdfData, "\x00\x09\x0a\x0c\x0d\x20", $startxref);
153
        // initialize object number
154 22
        $obj_num = 0;
155
        // search for cross-reference entries or subsection
156 22
        while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset) > 0) {
157 22
            if ($matches[0][1] != $offset) {
158
                // we are on another section
159 5
                break;
160
            }
161 22
            $offset += \strlen($matches[0][0]);
162 22
            if ('n' == $matches[3][0]) {
163
                // create unique object index: [object number]_[generation number]
164 22
                $index = $obj_num.'_'.(int) ($matches[2][0]);
165
                // check if object already exist
166 22
                if (!isset($xref['xref'][$index])) {
167
                    // store object offset position
168 22
                    $xref['xref'][$index] = (int) ($matches[1][0]);
169
                }
170 22
                ++$obj_num;
171 22
            } elseif ('f' == $matches[3][0]) {
172 22
                ++$obj_num;
173
            } else {
174
                // object number (index)
175 22
                $obj_num = (int) ($matches[1][0]);
176
            }
177
        }
178
        // get trailer data
179 22
        if (preg_match('/trailer[\s]*<<(.*)>>/isU', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset) > 0) {
180 22
            $trailer_data = $matches[1][0];
181 22
            if (!isset($xref['trailer']) || empty($xref['trailer'])) {
182
                // get only the last updated version
183 22
                $xref['trailer'] = [];
184
                // parse trailer_data
185 22
                if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
186 22
                    $xref['trailer']['size'] = (int) ($matches[1]);
187
                }
188 22
                if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
189 22
                    $xref['trailer']['root'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
190
                }
191 22
                if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
192
                    $xref['trailer']['encrypt'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
193
                }
194 22
                if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
195 22
                    $xref['trailer']['info'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
196
                }
197 22
                if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) {
198 21
                    $xref['trailer']['id'] = [];
199 21
                    $xref['trailer']['id'][0] = $matches[1];
200 21
                    $xref['trailer']['id'][1] = $matches[2];
201
                }
202
            }
203 22
            if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
204
                // get previous xref
205 22
                $xref = $this->getXrefData($pdfData, (int) ($matches[1]), $xref);
206
            }
207
        } else {
208
            throw new Exception('Unable to find trailer');
209
        }
210
211 22
        return $xref;
212
    }
213
214
    /**
215
     * Decode the Cross-Reference Stream section
216
     *
217
     * @param string $pdfData   PDF data
218
     * @param int    $startxref Offset at which the xref section starts
219
     * @param array  $xref      Previous xref array (if any)
220
     *
221
     * @return array containing xref and trailer data
222
     *
223
     * @throws Exception if unknown PNG predictor detected
224
     */
225 5
    protected function decodeXrefStream($pdfData, $startxref, $xref = [])
226
    {
227
        // try to read Cross-Reference Stream
228 5
        $xrefobj = $this->getRawObject($pdfData, $startxref);
229 5
        $xrefcrs = $this->getIndirectObject($pdfData, $xref, $xrefobj[1], $startxref, true);
230 5
        if (!isset($xref['trailer']) || empty($xref['trailer'])) {
231
            // get only the last updated version
232 5
            $xref['trailer'] = [];
233 5
            $filltrailer = true;
234
        } else {
235 4
            $filltrailer = false;
236
        }
237 5
        if (!isset($xref['xref'])) {
238 5
            $xref['xref'] = [];
239
        }
240 5
        $valid_crs = false;
241 5
        $columns = 0;
242 5
        $sarr = $xrefcrs[0][1];
243 5
        if (!\is_array($sarr)) {
244
            $sarr = [];
245
        }
246
247 5
        $wb = [];
248
249 5
        foreach ($sarr as $k => $v) {
250
            if (
251 5
                ('/' == $v[0])
252 5
                && ('Type' == $v[1])
253
                && (
254 5
                    isset($sarr[($k + 1)])
255 5
                    && '/' == $sarr[($k + 1)][0]
256 5
                    && 'XRef' == $sarr[($k + 1)][1]
257
                )
258
            ) {
259 5
                $valid_crs = true;
260 5
            } elseif (('/' == $v[0]) && ('Index' == $v[1]) && (isset($sarr[($k + 1)]))) {
261
                // first object number in the subsection
262 4
                $index_first = (int) ($sarr[($k + 1)][1][0][1]);
263 5
            } elseif (('/' == $v[0]) && ('Prev' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) {
264
                // get previous xref offset
265 4
                $prevxref = (int) ($sarr[($k + 1)][1]);
266 5
            } elseif (('/' == $v[0]) && ('W' == $v[1]) && (isset($sarr[($k + 1)]))) {
267
                // number of bytes (in the decoded stream) of the corresponding field
268 5
                $wb[0] = (int) ($sarr[($k + 1)][1][0][1]);
269 5
                $wb[1] = (int) ($sarr[($k + 1)][1][1][1]);
270 5
                $wb[2] = (int) ($sarr[($k + 1)][1][2][1]);
271 5
            } elseif (('/' == $v[0]) && ('DecodeParms' == $v[1]) && (isset($sarr[($k + 1)][1]))) {
272 5
                $decpar = $sarr[($k + 1)][1];
273 5
                foreach ($decpar as $kdc => $vdc) {
274
                    if (
275 5
                        '/' == $vdc[0]
276 5
                        && 'Columns' == $vdc[1]
277
                        && (
278 5
                            isset($decpar[($kdc + 1)])
279 5
                            && 'numeric' == $decpar[($kdc + 1)][0]
280
                        )
281
                    ) {
282 5
                        $columns = (int) ($decpar[($kdc + 1)][1]);
283
                    } elseif (
284 5
                        '/' == $vdc[0]
285 5
                        && 'Predictor' == $vdc[1]
286
                        && (
287 5
                            isset($decpar[($kdc + 1)])
288 5
                            && 'numeric' == $decpar[($kdc + 1)][0]
289
                        )
290
                    ) {
291 5
                        $predictor = (int) ($decpar[($kdc + 1)][1]);
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292
                    }
293
                }
294 5
            } elseif ($filltrailer) {
295 5
                if (('/' == $v[0]) && ('Size' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) {
296 5
                    $xref['trailer']['size'] = $sarr[($k + 1)][1];
297 5
                } elseif (('/' == $v[0]) && ('Root' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
298 5
                    $xref['trailer']['root'] = $sarr[($k + 1)][1];
299 5
                } elseif (('/' == $v[0]) && ('Info' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
300 5
                    $xref['trailer']['info'] = $sarr[($k + 1)][1];
301 5
                } elseif (('/' == $v[0]) && ('Encrypt' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
302
                    $xref['trailer']['encrypt'] = $sarr[($k + 1)][1];
303 5
                } elseif (('/' == $v[0]) && ('ID' == $v[1]) && (isset($sarr[($k + 1)]))) {
304 5
                    $xref['trailer']['id'] = [];
305 5
                    $xref['trailer']['id'][0] = $sarr[($k + 1)][1][0][1];
306 5
                    $xref['trailer']['id'][1] = $sarr[($k + 1)][1][1][1];
307
                }
308
            }
309
        }
310
311
        // decode data
312 5
        if ($valid_crs && isset($xrefcrs[1][3][0])) {
313
            // number of bytes in a row
314 5
            $rowlen = ($columns + 1);
315
            // convert the stream into an array of integers
316 5
            $sdata = unpack('C*', $xrefcrs[1][3][0]);
317
            // split the rows
318 5
            $sdata = array_chunk($sdata, $rowlen);
319
            // initialize decoded array
320 5
            $ddata = [];
321
            // initialize first row with zeros
322 5
            $prev_row = array_fill(0, $rowlen, 0);
323
            // for each row apply PNG unpredictor
324 5
            foreach ($sdata as $k => $row) {
325
                // initialize new row
326 5
                $ddata[$k] = [];
327
                // get PNG predictor value
328 5
                $predictor = (10 + $row[0]);
329
                // for each byte on the row
330 5
                for ($i = 1; $i <= $columns; ++$i) {
331
                    // new index
332 5
                    $j = ($i - 1);
333 5
                    $row_up = $prev_row[$j];
334 5
                    if (1 == $i) {
335 5
                        $row_left = 0;
336 5
                        $row_upleft = 0;
337
                    } else {
338 5
                        $row_left = $row[($i - 1)];
339 5
                        $row_upleft = $prev_row[($j - 1)];
340
                    }
341 5
                    switch ($predictor) {
342 5
                        case 10:  // PNG prediction (on encoding, PNG None on all rows)
343
                            $ddata[$k][$j] = $row[$i];
344
                            break;
345
346 5
                        case 11:  // PNG prediction (on encoding, PNG Sub on all rows)
347
                            $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
348
                            break;
349
350 5
                        case 12:  // PNG prediction (on encoding, PNG Up on all rows)
351 5
                            $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
352 5
                            break;
353
354
                        case 13:  // PNG prediction (on encoding, PNG Average on all rows)
355
                            $ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff);
356
                            break;
357
358
                        case 14:  // PNG prediction (on encoding, PNG Paeth on all rows)
359
                            // initial estimate
360
                            $p = ($row_left + $row_up - $row_upleft);
361
                            // distances
362
                            $pa = abs($p - $row_left);
363
                            $pb = abs($p - $row_up);
364
                            $pc = abs($p - $row_upleft);
365
                            $pmin = min($pa, $pb, $pc);
366
                            // return minimum distance
367
                            switch ($pmin) {
368
                                case $pa:
369
                                    $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
370
                                    break;
371
372
                                case $pb:
373
                                    $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
374
                                    break;
375
376
                                case $pc:
377
                                    $ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff);
378
                                    break;
379
                            }
380
                            break;
381
382
                        default:  // PNG prediction (on encoding, PNG optimum)
383
                            throw new Exception('Unknown PNG predictor');
384
                    }
385
                }
386 5
                $prev_row = $ddata[$k];
387
            } // end for each row
388
            // complete decoding
389 5
            $sdata = [];
390
            // for every row
391 5
            foreach ($ddata as $k => $row) {
392
                // initialize new row
393 5
                $sdata[$k] = [0, 0, 0];
394 5
                if (0 == $wb[0]) {
395
                    // default type field
396
                    $sdata[$k][0] = 1;
397
                }
398 5
                $i = 0; // count bytes in the row
399
                // for every column
400 5
                for ($c = 0; $c < 3; ++$c) {
401
                    // for every byte on the column
402 5
                    for ($b = 0; $b < $wb[$c]; ++$b) {
403 5
                        if (isset($row[$i])) {
404 5
                            $sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8));
405
                        }
406 5
                        ++$i;
407
                    }
408
                }
409
            }
410 5
            $ddata = [];
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411
            // fill xref
412 5
            if (isset($index_first)) {
413 4
                $obj_num = $index_first;
414
            } else {
415 5
                $obj_num = 0;
416
            }
417 5
            foreach ($sdata as $k => $row) {
418 5
                switch ($row[0]) {
419 5
                    case 0:  // (f) linked list of free objects
420 5
                            break;
421
422 5
                    case 1:  // (n) objects that are in use but are not compressed
423
                            // create unique object index: [object number]_[generation number]
424 5
                            $index = $obj_num.'_'.$row[2];
425
                            // check if object already exist
426 5
                            if (!isset($xref['xref'][$index])) {
427
                                // store object offset position
428 5
                                $xref['xref'][$index] = $row[1];
429
                            }
430 5
                            break;
431
432 5
                    case 2:  // compressed objects
433
                            // $row[1] = object number of the object stream in which this object is stored
434
                            // $row[2] = index of this object within the object stream
435 5
                            $index = $row[1].'_0_'.$row[2];
436 5
                            $xref['xref'][$index] = -1;
437 5
                            break;
438
439
                    default:  // null objects
440
                            break;
441
                }
442 5
                ++$obj_num;
443
            }
444
        } // end decoding data
445 5
        if (isset($prevxref)) {
446
            // get previous xref
447 4
            $xref = $this->getXrefData($pdfData, $prevxref, $xref);
448
        }
449
450 5
        return $xref;
451
    }
452
453
    /**
454
     * Get content of indirect object.
455
     *
456
     * @param string $pdfData  PDF data
457
     * @param array  $xref
458
     * @param string $objRef   Object number and generation number separated by underscore character
459
     * @param int    $offset   Object offset
460
     * @param bool   $decoding If true decode streams
461
     *
462
     * @return array containing object data
463
     *
464
     * @throws Exception if invalid object reference found
465
     */
466 26
    protected function getIndirectObject($pdfData, $xref, $objRef, $offset = 0, $decoding = true)
467
    {
468
        /*
469
         * build indirect object header
470
         */
471
        // $objHeader = "[object number] [generation number] obj"
472 26
        $objRefArr = explode('_', $objRef);
473 26
        if (2 !== \count($objRefArr)) {
474
            throw new Exception('Invalid object reference for $obj.');
475
        }
476 26
        $objHeader = $objRefArr[0].' '.$objRefArr[1].' obj';
477
478
        /*
479
         * check if we are in position
480
         */
481
        // ignore whitespace characters at offset (NUL, HT, LF, FF, CR, SP)
482 26
        $offset += strspn($pdfData, "\0\t\n\f\r ", $offset);
483
        // ignore leading zeros for object number
484 26
        $offset += strspn($pdfData, '0', $offset);
485 26
        if (substr($pdfData, $offset, \strlen($objHeader)) !== $objHeader) {
486
            // an indirect reference to an undefined object shall be considered a reference to the null object
487 2
            return ['null', 'null', $offset];
488
        }
489
490
        /*
491
         * get content
492
         */
493
        // starting position of object content
494 26
        $offset += \strlen($objHeader);
495 26
        $objContentArr = [];
496 26
        $i = 0; // object main index
497
        do {
498 26
            $oldOffset = $offset;
499
            // get element
500 26
            $element = $this->getRawObject($pdfData, $offset);
501 26
            $offset = $element[2];
502
            // decode stream using stream's dictionary information
503 26
            if ($decoding && ('stream' === $element[0]) && (isset($objContentArr[($i - 1)][0])) && ('<<' === $objContentArr[($i - 1)][0])) {
504 26
                $element[3] = $this->decodeStream($pdfData, $xref, $objContentArr[($i - 1)][1], $element[1]);
505
            }
506 26
            $objContentArr[$i] = $element;
507 26
            ++$i;
508 26
        } while (('endobj' !== $element[0]) && ($offset !== $oldOffset));
509
        // remove closing delimiter
510 26
        array_pop($objContentArr);
511
512
        /*
513
         * return raw object content
514
         */
515 26
        return $objContentArr;
516
    }
517
518
    /**
519
     * Get the content of object, resolving indirect object reference if necessary.
520
     *
521
     * @param string $pdfData PDF data
522
     * @param array  $obj     Object value
523
     *
524
     * @return array containing object data
525
     *
526
     * @throws Exception
527
     */
528 26
    protected function getObjectVal($pdfData, $xref, $obj)
529
    {
530 26
        if ('objref' == $obj[0]) {
531
            // reference to indirect object
532
            if (isset($this->objects[$obj[1]])) {
533
                // this object has been already parsed
534
                return $this->objects[$obj[1]];
535
            } elseif (isset($xref[$obj[1]])) {
536
                // parse new object
537
                $this->objects[$obj[1]] = $this->getIndirectObject($pdfData, $xref, $obj[1], $xref[$obj[1]], false);
538
539
                return $this->objects[$obj[1]];
540
            }
541
        }
542
543 26
        return $obj;
544
    }
545
546
    /**
547
     * Get object type, raw value and offset to next object
548
     *
549
     * @param int $offset Object offset
550
     *
551
     * @return array containing object type, raw value and offset to next object
552
     */
553 27
    protected function getRawObject($pdfData, $offset = 0)
554
    {
555 27
        $objtype = ''; // object type to be returned
556 27
        $objval = ''; // object value to be returned
557
558
        /*
559
         * skip initial white space chars:
560
         *      \x00 null (NUL)
561
         *      \x09 horizontal tab (HT)
562
         *      \x0A line feed (LF)
563
         *      \x0C form feed (FF)
564
         *      \x0D carriage return (CR)
565
         *      \x20 space (SP)
566
         */
567 27
        $offset += strspn($pdfData, "\x00\x09\x0a\x0c\x0d\x20", $offset);
568
569
        // get first char
570 27
        $char = $pdfData[$offset];
571
        // get object type
572 27
        switch ($char) {
573 27
            case '%':  // \x25 PERCENT SIGN
574
                    // skip comment and search for next token
575
                    $next = strcspn($pdfData, "\r\n", $offset);
576
                    if ($next > 0) {
577
                        $offset += $next;
578
579
                        return $this->getRawObject($pdfData, $offset);
580
                    }
581
                    break;
582
583 27
            case '/':  // \x2F SOLIDUS
584
                    // name object
585 27
                    $objtype = $char;
586 27
                    ++$offset;
587 27
                    $pregResult = preg_match(
588 27
                        '/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/',
589 27
                        substr($pdfData, $offset, 256),
590
                        $matches
591
                    );
592 27
                    if (1 == $pregResult) {
593 27
                        $objval = $matches[1]; // unescaped value
594 27
                        $offset += \strlen($objval);
595
                    }
596 27
                    break;
597
598 27
            case '(':   // \x28 LEFT PARENTHESIS
599 27
            case ')':  // \x29 RIGHT PARENTHESIS
600
                    // literal string object
601 25
                    $objtype = $char;
602 25
                    ++$offset;
603 25
                    $strpos = $offset;
604 25
                    if ('(' == $char) {
605 25
                        $open_bracket = 1;
606 25
                        while ($open_bracket > 0) {
607 25
                            if (!isset($pdfData[$strpos])) {
608
                                break;
609
                            }
610 25
                            $ch = $pdfData[$strpos];
611 25
                            switch ($ch) {
612 25
                                case '\\':  // REVERSE SOLIDUS (5Ch) (Backslash)
613
                                        // skip next character
614 15
                                        ++$strpos;
615 15
                                        break;
616
617 25
                                case '(':  // LEFT PARENHESIS (28h)
618
                                        ++$open_bracket;
619
                                        break;
620
621 25
                                case ')':  // RIGHT PARENTHESIS (29h)
622 25
                                        --$open_bracket;
623 25
                                        break;
624
                            }
625 25
                            ++$strpos;
626
                        }
627 25
                        $objval = substr($pdfData, $offset, ($strpos - $offset - 1));
628 25
                        $offset = $strpos;
629
                    }
630 25
                    break;
631
632 27
            case '[':   // \x5B LEFT SQUARE BRACKET
633 27
            case ']':  // \x5D RIGHT SQUARE BRACKET
634
                // array object
635 26
                $objtype = $char;
636 26
                ++$offset;
637 26
                if ('[' == $char) {
638
                    // get array content
639 26
                    $objval = [];
640
                    do {
641 26
                        $oldOffset = $offset;
642
                        // get element
643 26
                        $element = $this->getRawObject($pdfData, $offset);
644 26
                        $offset = $element[2];
645 26
                        $objval[] = $element;
646 26
                    } while ((']' != $element[0]) && ($offset != $oldOffset));
647
                    // remove closing delimiter
648 26
                    array_pop($objval);
649
                }
650 26
                break;
651
652 27
            case '<':  // \x3C LESS-THAN SIGN
653 27
            case '>':  // \x3E GREATER-THAN SIGN
654 27
                if (isset($pdfData[($offset + 1)]) && ($pdfData[($offset + 1)] == $char)) {
655
                    // dictionary object
656 27
                    $objtype = $char.$char;
657 27
                    $offset += 2;
658 27
                    if ('<' == $char) {
659
                        // get array content
660 27
                        $objval = [];
661
                        do {
662 27
                            $oldOffset = $offset;
663
                            // get element
664 27
                            $element = $this->getRawObject($pdfData, $offset);
665 27
                            $offset = $element[2];
666 27
                            $objval[] = $element;
667 27
                        } while (('>>' != $element[0]) && ($offset != $oldOffset));
668
                        // remove closing delimiter
669 27
                        array_pop($objval);
670
                    }
671
                } else {
672
                    // hexadecimal string object
673 9
                    $objtype = $char;
674 9
                    ++$offset;
675 9
                    $pregResult = preg_match(
676 9
                            '/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU',
677 9
                            substr($pdfData, $offset),
678
                            $matches
679
                        );
680 9
                    if (('<' == $char) && 1 == $pregResult) {
681
                        // remove white space characters
682 9
                        $objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
683 9
                        $offset += \strlen($matches[0]);
684
                    } elseif (false !== ($endpos = strpos($pdfData, '>', $offset))) {
685
                        $offset = $endpos + 1;
686
                    }
687
                }
688 27
                    break;
689
690
            default:
691 27
                    if ('endobj' == substr($pdfData, $offset, 6)) {
692
                        // indirect object
693 26
                        $objtype = 'endobj';
694 26
                        $offset += 6;
695 27
                    } elseif ('null' == substr($pdfData, $offset, 4)) {
696
                        // null object
697 3
                        $objtype = 'null';
698 3
                        $offset += 4;
699 3
                        $objval = 'null';
700 27
                    } elseif ('true' == substr($pdfData, $offset, 4)) {
701
                        // boolean true object
702 8
                        $objtype = 'boolean';
703 8
                        $offset += 4;
704 8
                        $objval = 'true';
705 27
                    } elseif ('false' == substr($pdfData, $offset, 5)) {
706
                        // boolean false object
707 2
                        $objtype = 'boolean';
708 2
                        $offset += 5;
709 2
                        $objval = 'false';
710 27
                    } elseif ('stream' == substr($pdfData, $offset, 6)) {
711
                        // start stream object
712 26
                        $objtype = 'stream';
713 26
                        $offset += 6;
714 26
                        if (1 == preg_match('/^([\r]?[\n])/isU', substr($pdfData, $offset), $matches)) {
715 26
                            $offset += \strlen($matches[0]);
716 26
                            $pregResult = preg_match(
717 26
                                '/(endstream)[\x09\x0a\x0c\x0d\x20]/isU',
718 26
                                substr($pdfData, $offset),
719
                                $matches,
720 26
                                \PREG_OFFSET_CAPTURE
721
                            );
722 26
                            if (1 == $pregResult) {
723 26
                                $objval = substr($pdfData, $offset, $matches[0][1]);
724 26
                                $offset += $matches[1][1];
725
                            }
726
                        }
727 27
                    } elseif ('endstream' == substr($pdfData, $offset, 9)) {
728
                        // end stream object
729 26
                        $objtype = 'endstream';
730 26
                        $offset += 9;
731 27
                    } elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($pdfData, $offset, 33), $matches)) {
732
                        // indirect object reference
733 26
                        $objtype = 'objref';
734 26
                        $offset += \strlen($matches[0]);
735 26
                        $objval = (int) ($matches[1]).'_'.(int) ($matches[2]);
736 27
                    } elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($pdfData, $offset, 33), $matches)) {
737
                        // object start
738 5
                        $objtype = 'obj';
739 5
                        $objval = (int) ($matches[1]).'_'.(int) ($matches[2]);
740 5
                        $offset += \strlen($matches[0]);
741 27
                    } elseif (($numlen = strspn($pdfData, '+-.0123456789', $offset)) > 0) {
742
                        // numeric object
743 26
                        $objtype = 'numeric';
744 26
                        $objval = substr($pdfData, $offset, $numlen);
745 26
                        $offset += $numlen;
746
                    }
747 27
                    break;
748
        }
749
750 27
        return [$objtype, $objval, $offset];
751
    }
752
753
    /**
754
     * Get Cross-Reference (xref) table and trailer data from PDF document data.
755
     *
756
     * @param string $pdfData
757
     * @param int    $offset  xref offset (if know)
758
     * @param array  $xref    previous xref array (if any)
759
     *
760
     * @return array containing xref and trailer data
761
     *
762
     * @throws Exception if it was unable to find startxref
763
     * @throws Exception if it was unable to find xref
764
     */
765 27
    protected function getXrefData($pdfData, $offset = 0, $xref = [])
766
    {
767 27
        $startxrefPreg = preg_match(
768 27
            '/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i',
769
            $pdfData,
770
            $matches,
771 27
            \PREG_OFFSET_CAPTURE,
772
            $offset
773
        );
774
775 27
        if (0 == $offset) {
776
            // find last startxref
777 27
            $pregResult = preg_match_all(
778 27
                '/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i',
779
                $pdfData, $matches,
780 27
                \PREG_SET_ORDER,
781
                $offset
782
            );
783 27
            if (0 == $pregResult) {
784
                throw new Exception('Unable to find startxref');
785
            }
786 27
            $matches = array_pop($matches);
787 27
            $startxref = $matches[1];
788 8
        } elseif (strpos($pdfData, 'xref', $offset) == $offset) {
789
            // Already pointing at the xref table
790 5
            $startxref = $offset;
791 4
        } elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset)) {
792
            // Cross-Reference Stream object
793 4
            $startxref = $offset;
794
        } elseif ($startxrefPreg) {
795
            // startxref found
796
            $startxref = $matches[1][0];
797
        } else {
798
            throw new Exception('Unable to find startxref');
799
        }
800
801 27
        if ($startxref > \strlen($pdfData)) {
802 1
            throw new Exception('Unable to find xref (PDF corrupted?)');
803
        }
804
805
        // check xref position
806 26
        if (strpos($pdfData, 'xref', $startxref) == $startxref) {
807
            // Cross-Reference
808 22
            $xref = $this->decodeXref($pdfData, $startxref, $xref);
809
        } else {
810
            // Cross-Reference Stream
811 5
            $xref = $this->decodeXrefStream($pdfData, $startxref, $xref);
812
        }
813 26
        if (empty($xref)) {
814
            throw new Exception('Unable to find xref');
815
        }
816
817 26
        return $xref;
818
    }
819
820
    /**
821
     * Parses PDF data and returns extracted data as array.
822
     *
823
     * @param string $data PDF data to parse
824
     *
825
     * @return array array of parsed PDF document objects
826
     *
827
     * @throws Exception if empty PDF data given
828
     * @throws Exception if PDF data missing %PDF header
829
     */
830 27
    public function parseData($data)
831
    {
832 27
        if (empty($data)) {
833
            throw new Exception('Empty PDF data given.');
834
        }
835
        // find the pdf header starting position
836 27
        if (false === ($trimpos = strpos($data, '%PDF-'))) {
837
            throw new Exception('Invalid PDF data: missing %PDF header.');
838
        }
839
840
        // get PDF content string
841 27
        $pdfData = substr($data, $trimpos);
842
843
        // get xref and trailer data
844 27
        $xref = $this->getXrefData($pdfData);
845
846
        // parse all document objects
847 26
        $objects = [];
848 26
        foreach ($xref['xref'] as $obj => $offset) {
849 26
            if (!isset($objects[$obj]) && ($offset > 0)) {
850
                // decode objects with positive offset
851 26
                $objects[$obj] = $this->getIndirectObject($pdfData, $xref, $obj, $offset, true);
852
            }
853
        }
854
855 26
        return [$xref, $objects];
856
    }
857
}
858