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<?php |
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/** |
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* This file is based on code of tecnickcom/TCPDF PDF library. |
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* |
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* Original author Nicola Asuni ([email protected]) and |
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* contributors (https://github.com/tecnickcom/TCPDF/graphs/contributors). |
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* |
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* @see https://github.com/tecnickcom/TCPDF |
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* |
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* Original code was licensed on the terms of the LGPL v3. |
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* |
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* ------------------------------------------------------------------------------ |
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* |
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* @file This file is part of the PdfParser library. |
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* |
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* @author Konrad Abicht <[email protected]> |
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* @date 2020-01-06 |
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* |
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* @license LGPLv3 |
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* @url <https://github.com/smalot/pdfparser> |
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* |
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* PdfParser is a pdf library written in PHP, extraction oriented. |
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* Copyright (C) 2017 - Sébastien MALOT <[email protected]> |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Lesser General Public License as published by |
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* the Free Software Foundation, either version 3 of the License, or |
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* (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public License |
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* along with this program. |
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* If not, see <http://www.pdfparser.org/sites/default/LICENSE.txt>. |
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*/ |
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namespace Smalot\PdfParser\RawData; |
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use Exception; |
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use Smalot\PdfParser\Config; |
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class RawDataParser |
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{ |
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/** |
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* @var \Smalot\PdfParser\Config |
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*/ |
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private $config; |
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/** |
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* Configuration array. |
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*/ |
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protected $cfg = [ |
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// if `true` ignore filter decoding errors |
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'ignore_filter_decoding_errors' => true, |
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// if `true` ignore missing filter decoding errors |
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'ignore_missing_filter_decoders' => true, |
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]; |
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protected $filterHelper; |
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protected $objects; |
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/** |
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* @param array $cfg Configuration array, default is [] |
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*/ |
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public function __construct($cfg = [], Config $config = null) |
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{ |
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// merge given array with default values |
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$this->cfg = array_merge($this->cfg, $cfg); |
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$this->filterHelper = new FilterHelper(); |
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$this->config = $config ?: new Config(); |
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} |
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/** |
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* Decode the specified stream. |
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* |
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* @param string $pdfData PDF data |
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* @param array $sdic Stream's dictionary array |
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* @param string $stream Stream to decode |
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* |
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* @return array containing decoded stream data and remaining filters |
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* |
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* @throws Exception |
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*/ |
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protected function decodeStream(string $pdfData, array $xref, array $sdic, string $stream): array |
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{ |
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// get stream length and filters |
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$slength = \strlen($stream); |
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if ($slength <= 0) { |
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return ['', []]; |
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} |
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$filters = []; |
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foreach ($sdic as $k => $v) { |
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if ('/' == $v[0]) { |
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if (('Length' == $v[1]) && (isset($sdic[($k + 1)])) && ('numeric' == $sdic[($k + 1)][0])) { |
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// get declared stream length |
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$declength = (int) ($sdic[($k + 1)][1]); |
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if ($declength < $slength) { |
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$stream = substr($stream, 0, $declength); |
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$slength = $declength; |
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} |
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} elseif (('Filter' == $v[1]) && (isset($sdic[($k + 1)]))) { |
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// resolve indirect object |
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$objval = $this->getObjectVal($pdfData, $xref, $sdic[($k + 1)]); |
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if ('/' == $objval[0]) { |
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// single filter |
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$filters[] = $objval[1]; |
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} elseif ('[' == $objval[0]) { |
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// array of filters |
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foreach ($objval[1] as $flt) { |
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if ('/' == $flt[0]) { |
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$filters[] = $flt[1]; |
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} |
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} |
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} |
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} |
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} |
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} |
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// decode the stream |
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$remaining_filters = []; |
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foreach ($filters as $filter) { |
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if (\in_array($filter, $this->filterHelper->getAvailableFilters())) { |
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try { |
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$stream = $this->filterHelper->decodeFilter($filter, $stream, $this->config->getDecodeMemoryLimit()); |
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} catch (Exception $e) { |
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$emsg = $e->getMessage(); |
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if ((('~' == $emsg[0]) && !$this->cfg['ignore_missing_filter_decoders']) |
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|| (('~' != $emsg[0]) && !$this->cfg['ignore_filter_decoding_errors']) |
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) { |
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throw new Exception($e->getMessage()); |
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} |
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} |
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} else { |
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// add missing filter to array |
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$remaining_filters[] = $filter; |
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} |
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} |
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return [$stream, $remaining_filters]; |
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} |
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/** |
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* Decode the Cross-Reference section |
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* |
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* @param string $pdfData PDF data |
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* @param int $startxref Offset at which the xref section starts (position of the 'xref' keyword) |
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* @param array $xref Previous xref array (if any) |
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* |
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* @return array containing xref and trailer data |
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* |
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* @throws Exception |
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*/ |
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protected function decodeXref(string $pdfData, int $startxref, array $xref = []): array |
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{ |
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$startxref += 4; // 4 is the length of the word 'xref' |
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// skip initial white space chars |
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$offset = $startxref + strspn($pdfData, $this->config->getPdfWhitespaces(), $startxref); |
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// initialize object number |
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$obj_num = 0; |
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// search for cross-reference entries or subsection |
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while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset) > 0) { |
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if ($matches[0][1] != $offset) { |
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// we are on another section |
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break; |
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} |
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$offset += \strlen($matches[0][0]); |
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if ('n' == $matches[3][0]) { |
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// create unique object index: [object number]_[generation number] |
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$index = $obj_num.'_'.(int) ($matches[2][0]); |
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// check if object already exist |
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if (!isset($xref['xref'][$index])) { |
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// store object offset position |
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$xref['xref'][$index] = (int) ($matches[1][0]); |
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} |
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++$obj_num; |
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} elseif ('f' == $matches[3][0]) { |
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++$obj_num; |
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} else { |
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// object number (index) |
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$obj_num = (int) ($matches[1][0]); |
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} |
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} |
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// get trailer data |
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if (preg_match('/trailer[\s]*<<(.*)>>/isU', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset) > 0) { |
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$trailer_data = $matches[1][0]; |
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if (!isset($xref['trailer']) || empty($xref['trailer'])) { |
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// get only the last updated version |
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$xref['trailer'] = []; |
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// parse trailer_data |
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if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) { |
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$xref['trailer']['size'] = (int) ($matches[1]); |
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} |
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if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { |
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$xref['trailer']['root'] = (int) ($matches[1]).'_'.(int) ($matches[2]); |
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} |
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if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { |
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$xref['trailer']['encrypt'] = (int) ($matches[1]).'_'.(int) ($matches[2]); |
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} |
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if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { |
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$xref['trailer']['info'] = (int) ($matches[1]).'_'.(int) ($matches[2]); |
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} |
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if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) { |
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$xref['trailer']['id'] = []; |
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$xref['trailer']['id'][0] = $matches[1]; |
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$xref['trailer']['id'][1] = $matches[2]; |
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} |
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} |
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if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) { |
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// get previous xref |
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$xref = $this->getXrefData($pdfData, (int) ($matches[1]), $xref); |
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} |
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} else { |
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throw new Exception('Unable to find trailer'); |
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} |
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return $xref; |
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} |
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/** |
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* Decode the Cross-Reference Stream section |
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* |
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* @param string $pdfData PDF data |
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* @param int $startxref Offset at which the xref section starts |
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* @param array $xref Previous xref array (if any) |
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* |
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* @return array containing xref and trailer data |
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* |
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* @throws Exception if unknown PNG predictor detected |
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*/ |
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protected function decodeXrefStream(string $pdfData, int $startxref, array $xref = []): array |
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{ |
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// try to read Cross-Reference Stream |
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$xrefobj = $this->getRawObject($pdfData, $startxref); |
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$xrefcrs = $this->getIndirectObject($pdfData, $xref, $xrefobj[1], $startxref, true); |
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6 |
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if (!isset($xref['trailer']) || empty($xref['trailer'])) { |
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// get only the last updated version |
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6 |
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$xref['trailer'] = []; |
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6 |
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$filltrailer = true; |
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} else { |
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$filltrailer = false; |
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} |
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6 |
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if (!isset($xref['xref'])) { |
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6 |
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$xref['xref'] = []; |
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} |
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6 |
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$valid_crs = false; |
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6 |
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$columns = 0; |
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6 |
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$predictor = null; |
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6 |
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$sarr = $xrefcrs[0][1]; |
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6 |
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if (!\is_array($sarr)) { |
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$sarr = []; |
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} |
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6 |
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$wb = []; |
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6 |
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foreach ($sarr as $k => $v) { |
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if ( |
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6 |
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('/' == $v[0]) |
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6 |
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&& ('Type' == $v[1]) |
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&& ( |
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6 |
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isset($sarr[($k + 1)]) |
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6 |
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&& '/' == $sarr[($k + 1)][0] |
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6 |
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&& 'XRef' == $sarr[($k + 1)][1] |
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) |
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) { |
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6 |
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$valid_crs = true; |
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6 |
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} elseif (('/' == $v[0]) && ('Index' == $v[1]) && (isset($sarr[($k + 1)]))) { |
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// initialize list for: first object number in the subsection / number of objects |
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4 |
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$index_blocks = []; |
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4 |
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for ($m = 0; $m < \count($sarr[($k + 1)][1]); $m += 2) { |
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4 |
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$index_blocks[] = [$sarr[($k + 1)][1][$m][1], $sarr[($k + 1)][1][$m + 1][1]]; |
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} |
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6 |
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} elseif (('/' == $v[0]) && ('Prev' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) { |
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// get previous xref offset |
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4 |
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$prevxref = (int) ($sarr[($k + 1)][1]); |
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6 |
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} elseif (('/' == $v[0]) && ('W' == $v[1]) && (isset($sarr[($k + 1)]))) { |
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// number of bytes (in the decoded stream) of the corresponding field |
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6 |
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$wb[0] = (int) ($sarr[($k + 1)][1][0][1]); |
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6 |
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$wb[1] = (int) ($sarr[($k + 1)][1][1][1]); |
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6 |
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$wb[2] = (int) ($sarr[($k + 1)][1][2][1]); |
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6 |
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} elseif (('/' == $v[0]) && ('DecodeParms' == $v[1]) && (isset($sarr[($k + 1)][1]))) { |
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5 |
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$decpar = $sarr[($k + 1)][1]; |
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5 |
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foreach ($decpar as $kdc => $vdc) { |
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if ( |
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289
|
5 |
|
'/' == $vdc[0] |
|
290
|
5 |
|
&& 'Columns' == $vdc[1] |
|
291
|
|
|
&& ( |
|
292
|
5 |
|
isset($decpar[($kdc + 1)]) |
|
293
|
5 |
|
&& 'numeric' == $decpar[($kdc + 1)][0] |
|
294
|
|
|
) |
|
295
|
|
|
) { |
|
296
|
5 |
|
$columns = (int) ($decpar[($kdc + 1)][1]); |
|
297
|
|
|
} elseif ( |
|
298
|
5 |
|
'/' == $vdc[0] |
|
299
|
5 |
|
&& 'Predictor' == $vdc[1] |
|
300
|
|
|
&& ( |
|
301
|
5 |
|
isset($decpar[($kdc + 1)]) |
|
302
|
5 |
|
&& 'numeric' == $decpar[($kdc + 1)][0] |
|
303
|
|
|
) |
|
304
|
|
|
) { |
|
305
|
5 |
|
$predictor = (int) ($decpar[($kdc + 1)][1]); |
|
306
|
|
|
} |
|
307
|
|
|
} |
|
308
|
6 |
|
} elseif ($filltrailer) { |
|
309
|
6 |
|
if (('/' == $v[0]) && ('Size' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) { |
|
310
|
6 |
|
$xref['trailer']['size'] = $sarr[($k + 1)][1]; |
|
311
|
6 |
|
} elseif (('/' == $v[0]) && ('Root' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) { |
|
312
|
6 |
|
$xref['trailer']['root'] = $sarr[($k + 1)][1]; |
|
313
|
6 |
|
} elseif (('/' == $v[0]) && ('Info' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) { |
|
314
|
6 |
|
$xref['trailer']['info'] = $sarr[($k + 1)][1]; |
|
315
|
6 |
|
} elseif (('/' == $v[0]) && ('Encrypt' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) { |
|
316
|
|
|
$xref['trailer']['encrypt'] = $sarr[($k + 1)][1]; |
|
317
|
6 |
|
} elseif (('/' == $v[0]) && ('ID' == $v[1]) && (isset($sarr[($k + 1)]))) { |
|
318
|
6 |
|
$xref['trailer']['id'] = []; |
|
319
|
6 |
|
$xref['trailer']['id'][0] = $sarr[($k + 1)][1][0][1]; |
|
320
|
6 |
|
$xref['trailer']['id'][1] = $sarr[($k + 1)][1][1][1]; |
|
321
|
|
|
} |
|
322
|
|
|
} |
|
323
|
|
|
} |
|
324
|
|
|
|
|
325
|
|
|
// decode data |
|
326
|
6 |
|
if ($valid_crs && isset($xrefcrs[1][3][0])) { |
|
327
|
6 |
|
if (null !== $predictor) { |
|
328
|
|
|
// number of bytes in a row |
|
329
|
5 |
|
$rowlen = ($columns + 1); |
|
330
|
|
|
// convert the stream into an array of integers |
|
331
|
5 |
|
$sdata = unpack('C*', $xrefcrs[1][3][0]); |
|
332
|
|
|
// split the rows |
|
333
|
5 |
|
$sdata = array_chunk($sdata, $rowlen); |
|
334
|
|
|
|
|
335
|
|
|
// initialize decoded array |
|
336
|
5 |
|
$ddata = []; |
|
337
|
|
|
// initialize first row with zeros |
|
338
|
5 |
|
$prev_row = array_fill(0, $rowlen, 0); |
|
339
|
|
|
// for each row apply PNG unpredictor |
|
340
|
5 |
|
foreach ($sdata as $k => $row) { |
|
341
|
|
|
// initialize new row |
|
342
|
5 |
|
$ddata[$k] = []; |
|
343
|
|
|
// get PNG predictor value |
|
344
|
5 |
|
$predictor = (10 + $row[0]); |
|
345
|
|
|
// for each byte on the row |
|
346
|
5 |
|
for ($i = 1; $i <= $columns; ++$i) { |
|
347
|
|
|
// new index |
|
348
|
5 |
|
$j = ($i - 1); |
|
349
|
5 |
|
$row_up = $prev_row[$j]; |
|
350
|
5 |
|
if (1 == $i) { |
|
351
|
5 |
|
$row_left = 0; |
|
352
|
5 |
|
$row_upleft = 0; |
|
353
|
|
|
} else { |
|
354
|
5 |
|
$row_left = $row[($i - 1)]; |
|
355
|
5 |
|
$row_upleft = $prev_row[($j - 1)]; |
|
356
|
|
|
} |
|
357
|
5 |
|
switch ($predictor) { |
|
358
|
5 |
|
case 10: // PNG prediction (on encoding, PNG None on all rows) |
|
359
|
|
|
$ddata[$k][$j] = $row[$i]; |
|
360
|
|
|
break; |
|
361
|
|
|
|
|
362
|
5 |
|
case 11: // PNG prediction (on encoding, PNG Sub on all rows) |
|
363
|
|
|
$ddata[$k][$j] = (($row[$i] + $row_left) & 0xff); |
|
364
|
|
|
break; |
|
365
|
|
|
|
|
366
|
5 |
|
case 12: // PNG prediction (on encoding, PNG Up on all rows) |
|
367
|
5 |
|
$ddata[$k][$j] = (($row[$i] + $row_up) & 0xff); |
|
368
|
5 |
|
break; |
|
369
|
|
|
|
|
370
|
|
|
case 13: // PNG prediction (on encoding, PNG Average on all rows) |
|
371
|
|
|
$ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff); |
|
372
|
|
|
break; |
|
373
|
|
|
|
|
374
|
|
|
case 14: // PNG prediction (on encoding, PNG Paeth on all rows) |
|
375
|
|
|
// initial estimate |
|
376
|
|
|
$p = ($row_left + $row_up - $row_upleft); |
|
377
|
|
|
// distances |
|
378
|
|
|
$pa = abs($p - $row_left); |
|
379
|
|
|
$pb = abs($p - $row_up); |
|
380
|
|
|
$pc = abs($p - $row_upleft); |
|
381
|
|
|
$pmin = min($pa, $pb, $pc); |
|
382
|
|
|
// return minimum distance |
|
383
|
|
|
switch ($pmin) { |
|
384
|
|
|
case $pa: |
|
385
|
|
|
$ddata[$k][$j] = (($row[$i] + $row_left) & 0xff); |
|
386
|
|
|
break; |
|
387
|
|
|
|
|
388
|
|
|
case $pb: |
|
389
|
|
|
$ddata[$k][$j] = (($row[$i] + $row_up) & 0xff); |
|
390
|
|
|
break; |
|
391
|
|
|
|
|
392
|
|
|
case $pc: |
|
393
|
|
|
$ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff); |
|
394
|
|
|
break; |
|
395
|
|
|
} |
|
396
|
|
|
break; |
|
397
|
|
|
|
|
398
|
|
|
default: // PNG prediction (on encoding, PNG optimum) |
|
399
|
|
|
throw new Exception('Unknown PNG predictor: '.$predictor); |
|
400
|
|
|
} |
|
401
|
|
|
} |
|
402
|
5 |
|
$prev_row = $ddata[$k]; |
|
403
|
|
|
} // end for each row |
|
404
|
|
|
// complete decoding |
|
405
|
|
|
} else { |
|
406
|
|
|
// number of bytes in a row |
|
407
|
1 |
|
$rowlen = array_sum($wb); |
|
408
|
|
|
// convert the stream into an array of integers |
|
409
|
1 |
|
$sdata = unpack('C*', $xrefcrs[1][3][0]); |
|
410
|
|
|
// split the rows |
|
411
|
1 |
|
$ddata = array_chunk($sdata, $rowlen); |
|
|
|
|
|
|
412
|
|
|
} |
|
413
|
|
|
|
|
414
|
6 |
|
$sdata = []; |
|
415
|
|
|
|
|
416
|
|
|
// for every row |
|
417
|
6 |
|
foreach ($ddata as $k => $row) { |
|
418
|
|
|
// initialize new row |
|
419
|
6 |
|
$sdata[$k] = [0, 0, 0]; |
|
420
|
6 |
|
if (0 == $wb[0]) { |
|
421
|
|
|
// default type field |
|
422
|
|
|
$sdata[$k][0] = 1; |
|
423
|
|
|
} |
|
424
|
6 |
|
$i = 0; // count bytes in the row |
|
425
|
|
|
// for every column |
|
426
|
6 |
|
for ($c = 0; $c < 3; ++$c) { |
|
427
|
|
|
// for every byte on the column |
|
428
|
6 |
|
for ($b = 0; $b < $wb[$c]; ++$b) { |
|
429
|
6 |
|
if (isset($row[$i])) { |
|
430
|
6 |
|
$sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8)); |
|
431
|
|
|
} |
|
432
|
6 |
|
++$i; |
|
433
|
|
|
} |
|
434
|
|
|
} |
|
435
|
|
|
} |
|
436
|
|
|
|
|
437
|
|
|
// fill xref |
|
438
|
6 |
|
if (isset($index_blocks)) { |
|
439
|
|
|
// load the first object number of the first /Index entry |
|
440
|
4 |
|
$obj_num = $index_blocks[0][0]; |
|
441
|
|
|
} else { |
|
442
|
6 |
|
$obj_num = 0; |
|
443
|
|
|
} |
|
444
|
6 |
|
foreach ($sdata as $k => $row) { |
|
445
|
6 |
|
switch ($row[0]) { |
|
446
|
6 |
|
case 0: // (f) linked list of free objects |
|
447
|
6 |
|
break; |
|
448
|
|
|
|
|
449
|
6 |
|
case 1: // (n) objects that are in use but are not compressed |
|
450
|
|
|
// create unique object index: [object number]_[generation number] |
|
451
|
6 |
|
$index = $obj_num.'_'.$row[2]; |
|
452
|
|
|
// check if object already exist |
|
453
|
6 |
|
if (!isset($xref['xref'][$index])) { |
|
454
|
|
|
// store object offset position |
|
455
|
6 |
|
$xref['xref'][$index] = $row[1]; |
|
456
|
|
|
} |
|
457
|
6 |
|
break; |
|
458
|
|
|
|
|
459
|
6 |
|
case 2: // compressed objects |
|
460
|
|
|
// $row[1] = object number of the object stream in which this object is stored |
|
461
|
|
|
// $row[2] = index of this object within the object stream |
|
462
|
6 |
|
$index = $row[1].'_0_'.$row[2]; |
|
463
|
6 |
|
$xref['xref'][$index] = -1; |
|
464
|
6 |
|
break; |
|
465
|
|
|
|
|
466
|
|
|
default: // null objects |
|
467
|
|
|
break; |
|
468
|
|
|
} |
|
469
|
6 |
|
++$obj_num; |
|
470
|
6 |
|
if (isset($index_blocks)) { |
|
471
|
|
|
// reduce the number of remaining objects |
|
472
|
4 |
|
--$index_blocks[0][1]; |
|
473
|
4 |
|
if (0 == $index_blocks[0][1]) { |
|
|
|
|
|
|
474
|
|
|
// remove the actual used /Index entry |
|
475
|
4 |
|
array_shift($index_blocks); |
|
476
|
4 |
|
if (0 < \count($index_blocks)) { |
|
477
|
|
|
// load the first object number of the following /Index entry |
|
478
|
2 |
|
$obj_num = $index_blocks[0][0]; |
|
479
|
|
|
} else { |
|
480
|
|
|
// if there are no more entries, remove $index_blocks to avoid actions on an empty array |
|
481
|
4 |
|
unset($index_blocks); |
|
482
|
|
|
} |
|
483
|
|
|
} |
|
484
|
|
|
} |
|
485
|
|
|
} |
|
486
|
|
|
} // end decoding data |
|
487
|
6 |
|
if (isset($prevxref)) { |
|
488
|
|
|
// get previous xref |
|
489
|
4 |
|
$xref = $this->getXrefData($pdfData, $prevxref, $xref); |
|
490
|
|
|
} |
|
491
|
|
|
|
|
492
|
6 |
|
return $xref; |
|
493
|
|
|
} |
|
494
|
|
|
|
|
495
|
35 |
|
protected function getObjectHeaderPattern(array $objRefs): string |
|
496
|
|
|
{ |
|
497
|
|
|
// consider all whitespace character (PDF specifications) |
|
498
|
35 |
|
return '/'.$objRefs[0].$this->config->getPdfWhitespacesRegex().$objRefs[1].$this->config->getPdfWhitespacesRegex().'obj'.'/'; |
|
499
|
|
|
} |
|
500
|
|
|
|
|
501
|
35 |
|
protected function getObjectHeaderLen(array $objRefs): int |
|
502
|
|
|
{ |
|
503
|
|
|
// "4 0 obj" |
|
504
|
|
|
// 2 whitespaces + strlen("obj") = 5 |
|
505
|
35 |
|
return 5 + \strlen($objRefs[0]) + \strlen($objRefs[1]); |
|
506
|
|
|
} |
|
507
|
|
|
|
|
508
|
|
|
/** |
|
509
|
|
|
* Get content of indirect object. |
|
510
|
|
|
* |
|
511
|
|
|
* @param string $pdfData PDF data |
|
512
|
|
|
* @param string $objRef Object number and generation number separated by underscore character |
|
513
|
|
|
* @param int $offset Object offset |
|
514
|
|
|
* @param bool $decoding If true decode streams |
|
515
|
|
|
* |
|
516
|
|
|
* @return array containing object data |
|
517
|
|
|
* |
|
518
|
|
|
* @throws Exception if invalid object reference found |
|
519
|
|
|
*/ |
|
520
|
35 |
|
protected function getIndirectObject(string $pdfData, array $xref, string $objRef, int $offset = 0, bool $decoding = true): array |
|
521
|
|
|
{ |
|
522
|
|
|
/* |
|
523
|
|
|
* build indirect object header |
|
524
|
|
|
*/ |
|
525
|
|
|
// $objHeader = "[object number] [generation number] obj" |
|
526
|
35 |
|
$objRefArr = explode('_', $objRef); |
|
527
|
35 |
|
if (2 !== \count($objRefArr)) { |
|
528
|
|
|
throw new Exception('Invalid object reference for $obj.'); |
|
529
|
|
|
} |
|
530
|
|
|
|
|
531
|
35 |
|
$objHeaderLen = $this->getObjectHeaderLen($objRefArr); |
|
532
|
|
|
|
|
533
|
|
|
/* |
|
534
|
|
|
* check if we are in position |
|
535
|
|
|
*/ |
|
536
|
|
|
// ignore whitespace characters at offset |
|
537
|
35 |
|
$offset += strspn($pdfData, $this->config->getPdfWhitespaces(), $offset); |
|
538
|
|
|
// ignore leading zeros for object number |
|
539
|
35 |
|
$offset += strspn($pdfData, '0', $offset); |
|
540
|
35 |
|
if (0 == preg_match($this->getObjectHeaderPattern($objRefArr), substr($pdfData, $offset, $objHeaderLen))) { |
|
541
|
|
|
// an indirect reference to an undefined object shall be considered a reference to the null object |
|
542
|
|
|
return ['null', 'null', $offset]; |
|
543
|
|
|
} |
|
544
|
|
|
|
|
545
|
|
|
/* |
|
546
|
|
|
* get content |
|
547
|
|
|
*/ |
|
548
|
|
|
// starting position of object content |
|
549
|
35 |
|
$offset += $objHeaderLen; |
|
550
|
35 |
|
$objContentArr = []; |
|
551
|
35 |
|
$i = 0; // object main index |
|
552
|
|
|
do { |
|
553
|
35 |
|
$oldOffset = $offset; |
|
554
|
|
|
// get element |
|
555
|
35 |
|
$element = $this->getRawObject($pdfData, $offset); |
|
556
|
35 |
|
$offset = $element[2]; |
|
557
|
|
|
// decode stream using stream's dictionary information |
|
558
|
35 |
|
if ($decoding && ('stream' === $element[0]) && (isset($objContentArr[($i - 1)][0])) && ('<<' === $objContentArr[($i - 1)][0])) { |
|
559
|
35 |
|
$element[3] = $this->decodeStream($pdfData, $xref, $objContentArr[($i - 1)][1], $element[1]); |
|
560
|
|
|
} |
|
561
|
35 |
|
$objContentArr[$i] = $element; |
|
562
|
35 |
|
++$i; |
|
563
|
35 |
|
} while (('endobj' !== $element[0]) && ($offset !== $oldOffset)); |
|
564
|
|
|
// remove closing delimiter |
|
565
|
35 |
|
array_pop($objContentArr); |
|
566
|
|
|
|
|
567
|
|
|
/* |
|
568
|
|
|
* return raw object content |
|
569
|
|
|
*/ |
|
570
|
35 |
|
return $objContentArr; |
|
571
|
|
|
} |
|
572
|
|
|
|
|
573
|
|
|
/** |
|
574
|
|
|
* Get the content of object, resolving indirect object reference if necessary. |
|
575
|
|
|
* |
|
576
|
|
|
* @param string $pdfData PDF data |
|
577
|
|
|
* @param array $obj Object value |
|
578
|
|
|
* |
|
579
|
|
|
* @return array containing object data |
|
580
|
|
|
* |
|
581
|
|
|
* @throws Exception |
|
582
|
|
|
*/ |
|
583
|
34 |
|
protected function getObjectVal(string $pdfData, $xref, array $obj): array |
|
584
|
|
|
{ |
|
585
|
34 |
|
if ('objref' == $obj[0]) { |
|
586
|
|
|
// reference to indirect object |
|
587
|
|
|
if (isset($this->objects[$obj[1]])) { |
|
588
|
|
|
// this object has been already parsed |
|
589
|
|
|
return $this->objects[$obj[1]]; |
|
590
|
|
|
} elseif (isset($xref[$obj[1]])) { |
|
591
|
|
|
// parse new object |
|
592
|
|
|
$this->objects[$obj[1]] = $this->getIndirectObject($pdfData, $xref, $obj[1], $xref[$obj[1]], false); |
|
593
|
|
|
|
|
594
|
|
|
return $this->objects[$obj[1]]; |
|
595
|
|
|
} |
|
596
|
|
|
} |
|
597
|
|
|
|
|
598
|
34 |
|
return $obj; |
|
599
|
|
|
} |
|
600
|
|
|
|
|
601
|
|
|
/** |
|
602
|
|
|
* Get object type, raw value and offset to next object |
|
603
|
|
|
* |
|
604
|
|
|
* @param int $offset Object offset |
|
605
|
|
|
* |
|
606
|
|
|
* @return array containing object type, raw value and offset to next object |
|
607
|
|
|
*/ |
|
608
|
36 |
|
protected function getRawObject(string $pdfData, int $offset = 0): array |
|
609
|
|
|
{ |
|
610
|
36 |
|
$objtype = ''; // object type to be returned |
|
611
|
36 |
|
$objval = ''; // object value to be returned |
|
612
|
|
|
|
|
613
|
|
|
// skip initial white space chars |
|
614
|
36 |
|
$offset += strspn($pdfData, $this->config->getPdfWhitespaces(), $offset); |
|
615
|
|
|
|
|
616
|
|
|
// get first char |
|
617
|
36 |
|
$char = $pdfData[$offset]; |
|
618
|
|
|
// get object type |
|
619
|
36 |
|
switch ($char) { |
|
620
|
36 |
|
case '%': // \x25 PERCENT SIGN |
|
621
|
|
|
// skip comment and search for next token |
|
622
|
1 |
|
$next = strcspn($pdfData, "\r\n", $offset); |
|
623
|
1 |
|
if ($next > 0) { |
|
624
|
1 |
|
$offset += $next; |
|
625
|
|
|
|
|
626
|
1 |
|
return $this->getRawObject($pdfData, $offset); |
|
627
|
|
|
} |
|
628
|
|
|
break; |
|
629
|
|
|
|
|
630
|
36 |
|
case '/': // \x2F SOLIDUS |
|
631
|
|
|
// name object |
|
632
|
36 |
|
$objtype = $char; |
|
633
|
36 |
|
++$offset; |
|
634
|
36 |
|
$pregResult = preg_match( |
|
635
|
36 |
|
'/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/', |
|
636
|
36 |
|
substr($pdfData, $offset, 256), |
|
637
|
|
|
$matches |
|
638
|
|
|
); |
|
639
|
36 |
|
if (1 == $pregResult) { |
|
640
|
36 |
|
$objval = $matches[1]; // unescaped value |
|
641
|
36 |
|
$offset += \strlen($objval); |
|
642
|
|
|
} |
|
643
|
36 |
|
break; |
|
644
|
|
|
|
|
645
|
36 |
|
case '(': // \x28 LEFT PARENTHESIS |
|
646
|
36 |
|
case ')': // \x29 RIGHT PARENTHESIS |
|
647
|
|
|
// literal string object |
|
648
|
33 |
|
$objtype = $char; |
|
649
|
33 |
|
++$offset; |
|
650
|
33 |
|
$strpos = $offset; |
|
651
|
33 |
|
if ('(' == $char) { |
|
652
|
33 |
|
$open_bracket = 1; |
|
653
|
33 |
|
while ($open_bracket > 0) { |
|
654
|
33 |
|
if (!isset($pdfData[$strpos])) { |
|
655
|
|
|
break; |
|
656
|
|
|
} |
|
657
|
33 |
|
$ch = $pdfData[$strpos]; |
|
658
|
33 |
|
switch ($ch) { |
|
659
|
33 |
|
case '\\': // REVERSE SOLIDUS (5Ch) (Backslash) |
|
660
|
|
|
// skip next character |
|
661
|
17 |
|
++$strpos; |
|
662
|
17 |
|
break; |
|
663
|
|
|
|
|
664
|
33 |
|
case '(': // LEFT PARENHESIS (28h) |
|
665
|
|
|
++$open_bracket; |
|
666
|
|
|
break; |
|
667
|
|
|
|
|
668
|
33 |
|
case ')': // RIGHT PARENTHESIS (29h) |
|
669
|
33 |
|
--$open_bracket; |
|
670
|
33 |
|
break; |
|
671
|
|
|
} |
|
672
|
33 |
|
++$strpos; |
|
673
|
|
|
} |
|
674
|
33 |
|
$objval = substr($pdfData, $offset, ($strpos - $offset - 1)); |
|
675
|
33 |
|
$offset = $strpos; |
|
676
|
|
|
} |
|
677
|
33 |
|
break; |
|
678
|
|
|
|
|
679
|
36 |
|
case '[': // \x5B LEFT SQUARE BRACKET |
|
680
|
36 |
|
case ']': // \x5D RIGHT SQUARE BRACKET |
|
681
|
|
|
// array object |
|
682
|
35 |
|
$objtype = $char; |
|
683
|
35 |
|
++$offset; |
|
684
|
35 |
|
if ('[' == $char) { |
|
685
|
|
|
// get array content |
|
686
|
35 |
|
$objval = []; |
|
687
|
|
|
do { |
|
688
|
35 |
|
$oldOffset = $offset; |
|
689
|
|
|
// get element |
|
690
|
35 |
|
$element = $this->getRawObject($pdfData, $offset); |
|
691
|
35 |
|
$offset = $element[2]; |
|
692
|
35 |
|
$objval[] = $element; |
|
693
|
35 |
|
} while ((']' != $element[0]) && ($offset != $oldOffset)); |
|
694
|
|
|
// remove closing delimiter |
|
695
|
35 |
|
array_pop($objval); |
|
696
|
|
|
} |
|
697
|
35 |
|
break; |
|
698
|
|
|
|
|
699
|
36 |
|
case '<': // \x3C LESS-THAN SIGN |
|
700
|
36 |
|
case '>': // \x3E GREATER-THAN SIGN |
|
701
|
36 |
|
if (isset($pdfData[($offset + 1)]) && ($pdfData[($offset + 1)] == $char)) { |
|
702
|
|
|
// dictionary object |
|
703
|
36 |
|
$objtype = $char.$char; |
|
704
|
36 |
|
$offset += 2; |
|
705
|
36 |
|
if ('<' == $char) { |
|
706
|
|
|
// get array content |
|
707
|
36 |
|
$objval = []; |
|
708
|
|
|
do { |
|
709
|
36 |
|
$oldOffset = $offset; |
|
710
|
|
|
// get element |
|
711
|
36 |
|
$element = $this->getRawObject($pdfData, $offset); |
|
712
|
36 |
|
$offset = $element[2]; |
|
713
|
36 |
|
$objval[] = $element; |
|
714
|
36 |
|
} while (('>>' != $element[0]) && ($offset != $oldOffset)); |
|
715
|
|
|
// remove closing delimiter |
|
716
|
36 |
|
array_pop($objval); |
|
717
|
|
|
} |
|
718
|
|
|
} else { |
|
719
|
|
|
// hexadecimal string object |
|
720
|
13 |
|
$objtype = $char; |
|
721
|
13 |
|
++$offset; |
|
722
|
13 |
|
$pregResult = preg_match( |
|
723
|
13 |
|
'/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', |
|
724
|
13 |
|
substr($pdfData, $offset), |
|
725
|
|
|
$matches |
|
726
|
|
|
); |
|
727
|
13 |
|
if (('<' == $char) && 1 == $pregResult) { |
|
728
|
|
|
// remove white space characters |
|
729
|
13 |
|
$objval = strtr($matches[1], $this->config->getPdfWhitespaces(), ''); |
|
730
|
13 |
|
$offset += \strlen($matches[0]); |
|
731
|
|
|
} elseif (false !== ($endpos = strpos($pdfData, '>', $offset))) { |
|
732
|
|
|
$offset = $endpos + 1; |
|
733
|
|
|
} |
|
734
|
|
|
} |
|
735
|
36 |
|
break; |
|
736
|
|
|
|
|
737
|
|
|
default: |
|
738
|
36 |
|
if ('endobj' == substr($pdfData, $offset, 6)) { |
|
739
|
|
|
// indirect object |
|
740
|
35 |
|
$objtype = 'endobj'; |
|
741
|
35 |
|
$offset += 6; |
|
742
|
36 |
|
} elseif ('null' == substr($pdfData, $offset, 4)) { |
|
743
|
|
|
// null object |
|
744
|
3 |
|
$objtype = 'null'; |
|
745
|
3 |
|
$offset += 4; |
|
746
|
3 |
|
$objval = 'null'; |
|
747
|
36 |
|
} elseif ('true' == substr($pdfData, $offset, 4)) { |
|
748
|
|
|
// boolean true object |
|
749
|
11 |
|
$objtype = 'boolean'; |
|
750
|
11 |
|
$offset += 4; |
|
751
|
11 |
|
$objval = 'true'; |
|
752
|
36 |
|
} elseif ('false' == substr($pdfData, $offset, 5)) { |
|
753
|
|
|
// boolean false object |
|
754
|
2 |
|
$objtype = 'boolean'; |
|
755
|
2 |
|
$offset += 5; |
|
756
|
2 |
|
$objval = 'false'; |
|
757
|
36 |
|
} elseif ('stream' == substr($pdfData, $offset, 6)) { |
|
758
|
|
|
// start stream object |
|
759
|
35 |
|
$objtype = 'stream'; |
|
760
|
35 |
|
$offset += 6; |
|
761
|
35 |
|
if (1 == preg_match('/^([\r]?[\n])/isU', substr($pdfData, $offset), $matches)) { |
|
762
|
35 |
|
$offset += \strlen($matches[0]); |
|
763
|
35 |
|
$pregResult = preg_match( |
|
764
|
35 |
|
'/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', |
|
765
|
35 |
|
substr($pdfData, $offset), |
|
766
|
|
|
$matches, |
|
767
|
35 |
|
\PREG_OFFSET_CAPTURE |
|
768
|
|
|
); |
|
769
|
35 |
|
if (1 == $pregResult) { |
|
770
|
35 |
|
$objval = substr($pdfData, $offset, $matches[0][1]); |
|
771
|
35 |
|
$offset += $matches[1][1]; |
|
772
|
|
|
} |
|
773
|
|
|
} |
|
774
|
36 |
|
} elseif ('endstream' == substr($pdfData, $offset, 9)) { |
|
775
|
|
|
// end stream object |
|
776
|
35 |
|
$objtype = 'endstream'; |
|
777
|
35 |
|
$offset += 9; |
|
778
|
36 |
|
} elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($pdfData, $offset, 33), $matches)) { |
|
779
|
|
|
// indirect object reference |
|
780
|
35 |
|
$objtype = 'objref'; |
|
781
|
35 |
|
$offset += \strlen($matches[0]); |
|
782
|
35 |
|
$objval = (int) ($matches[1]).'_'.(int) ($matches[2]); |
|
783
|
36 |
|
} elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($pdfData, $offset, 33), $matches)) { |
|
784
|
|
|
// object start |
|
785
|
6 |
|
$objtype = 'obj'; |
|
786
|
6 |
|
$objval = (int) ($matches[1]).'_'.(int) ($matches[2]); |
|
787
|
6 |
|
$offset += \strlen($matches[0]); |
|
788
|
36 |
|
} elseif (($numlen = strspn($pdfData, '+-.0123456789', $offset)) > 0) { |
|
789
|
|
|
// numeric object |
|
790
|
35 |
|
$objtype = 'numeric'; |
|
791
|
35 |
|
$objval = substr($pdfData, $offset, $numlen); |
|
792
|
35 |
|
$offset += $numlen; |
|
793
|
|
|
} |
|
794
|
36 |
|
break; |
|
795
|
|
|
} |
|
796
|
|
|
|
|
797
|
36 |
|
return [$objtype, $objval, $offset]; |
|
798
|
|
|
} |
|
799
|
|
|
|
|
800
|
|
|
/** |
|
801
|
|
|
* Get Cross-Reference (xref) table and trailer data from PDF document data. |
|
802
|
|
|
* |
|
803
|
|
|
* @param int $offset xref offset (if known) |
|
804
|
|
|
* @param array $xref previous xref array (if any) |
|
805
|
|
|
* |
|
806
|
|
|
* @return array containing xref and trailer data |
|
807
|
|
|
* |
|
808
|
|
|
* @throws Exception if it was unable to find startxref |
|
809
|
|
|
* @throws Exception if it was unable to find xref |
|
810
|
|
|
*/ |
|
811
|
36 |
|
protected function getXrefData(string $pdfData, int $offset = 0, array $xref = []): array |
|
812
|
|
|
{ |
|
813
|
36 |
|
$startxrefPreg = preg_match( |
|
814
|
36 |
|
'/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', |
|
815
|
|
|
$pdfData, |
|
816
|
|
|
$matches, |
|
817
|
36 |
|
\PREG_OFFSET_CAPTURE, |
|
818
|
|
|
$offset |
|
819
|
|
|
); |
|
820
|
|
|
|
|
821
|
36 |
|
if (0 == $offset) { |
|
822
|
|
|
// find last startxref |
|
823
|
36 |
|
$pregResult = preg_match_all( |
|
824
|
36 |
|
'/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', |
|
825
|
|
|
$pdfData, $matches, |
|
826
|
36 |
|
\PREG_SET_ORDER, |
|
827
|
|
|
$offset |
|
828
|
|
|
); |
|
829
|
36 |
|
if (0 == $pregResult) { |
|
|
|
|
|
|
830
|
|
|
throw new Exception('Unable to find startxref'); |
|
831
|
|
|
} |
|
832
|
36 |
|
$matches = array_pop($matches); |
|
833
|
36 |
|
$startxref = $matches[1]; |
|
834
|
9 |
|
} elseif (strpos($pdfData, 'xref', $offset) == $offset) { |
|
835
|
|
|
// Already pointing at the xref table |
|
836
|
5 |
|
$startxref = $offset; |
|
837
|
4 |
|
} elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $pdfData, $matches, \PREG_OFFSET_CAPTURE, $offset)) { |
|
838
|
|
|
// Cross-Reference Stream object |
|
839
|
4 |
|
$startxref = $offset; |
|
840
|
|
|
} elseif ($startxrefPreg) { |
|
841
|
|
|
// startxref found |
|
842
|
|
|
$startxref = $matches[1][0]; |
|
843
|
|
|
} else { |
|
844
|
|
|
throw new Exception('Unable to find startxref'); |
|
845
|
|
|
} |
|
846
|
|
|
|
|
847
|
36 |
|
if ($startxref > \strlen($pdfData)) { |
|
848
|
1 |
|
throw new Exception('Unable to find xref (PDF corrupted?)'); |
|
849
|
|
|
} |
|
850
|
|
|
|
|
851
|
|
|
// check xref position |
|
852
|
35 |
|
if (strpos($pdfData, 'xref', $startxref) == $startxref) { |
|
853
|
|
|
// Cross-Reference |
|
854
|
29 |
|
$xref = $this->decodeXref($pdfData, $startxref, $xref); |
|
855
|
|
|
} else { |
|
856
|
|
|
// Cross-Reference Stream |
|
857
|
6 |
|
$xref = $this->decodeXrefStream($pdfData, $startxref, $xref); |
|
858
|
|
|
} |
|
859
|
35 |
|
if (empty($xref)) { |
|
860
|
|
|
throw new Exception('Unable to find xref'); |
|
861
|
|
|
} |
|
862
|
|
|
|
|
863
|
35 |
|
return $xref; |
|
864
|
|
|
} |
|
865
|
|
|
|
|
866
|
|
|
/** |
|
867
|
|
|
* Parses PDF data and returns extracted data as array. |
|
868
|
|
|
* |
|
869
|
|
|
* @param string $data PDF data to parse |
|
870
|
|
|
* |
|
871
|
|
|
* @return array array of parsed PDF document objects |
|
872
|
|
|
* |
|
873
|
|
|
* @throws Exception if empty PDF data given |
|
874
|
|
|
* @throws Exception if PDF data missing %PDF header |
|
875
|
|
|
*/ |
|
876
|
36 |
|
public function parseData(string $data): array |
|
877
|
|
|
{ |
|
878
|
36 |
|
if (empty($data)) { |
|
879
|
|
|
throw new Exception('Empty PDF data given.'); |
|
880
|
|
|
} |
|
881
|
|
|
// find the pdf header starting position |
|
882
|
36 |
|
if (false === ($trimpos = strpos($data, '%PDF-'))) { |
|
883
|
|
|
throw new Exception('Invalid PDF data: missing %PDF header.'); |
|
884
|
|
|
} |
|
885
|
|
|
|
|
886
|
|
|
// get PDF content string |
|
887
|
36 |
|
$pdfData = substr($data, $trimpos); |
|
888
|
|
|
|
|
889
|
|
|
// get xref and trailer data |
|
890
|
36 |
|
$xref = $this->getXrefData($pdfData); |
|
891
|
|
|
|
|
892
|
|
|
// parse all document objects |
|
893
|
35 |
|
$objects = []; |
|
894
|
35 |
|
foreach ($xref['xref'] as $obj => $offset) { |
|
895
|
35 |
|
if (!isset($objects[$obj]) && ($offset > 0)) { |
|
896
|
|
|
// decode objects with positive offset |
|
897
|
35 |
|
$objects[$obj] = $this->getIndirectObject($pdfData, $xref, $obj, $offset, true); |
|
898
|
|
|
} |
|
899
|
|
|
} |
|
900
|
|
|
|
|
901
|
35 |
|
return [$xref, $objects]; |
|
902
|
|
|
} |
|
903
|
|
|
} |
|
904
|
|
|
|
smalot /
pdfparser
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If the size of the collection does not change during the iteration, it is generally a good practice to compute it beforehand, and not on each iteration: