查看文件: tcpdf_parser.php
大小: 24.02 KB
类型: application/octet-stream
<?php //============================================================+ // File name : tcpdf_parser.php // Version : 1.0.003 // Begin : 2011-05-23 // Last Update : 2013-03-17 // Author : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com // License : GNU-LGPL v3 (http://www.gnu.org/copyleft/lesser.html) // ------------------------------------------------------------------- // Copyright (C) 2011-2013 Nicola Asuni - Tecnick.com LTD // // This file is part of TCPDF software library. // // TCPDF is free software: you can redistribute it and/or modify it // under the terms of the GNU Lesser General Public License as // published by the Free Software Foundation, either version 3 of the // License, or (at your option) any later version. // // TCPDF is distributed in the hope that it will be useful, but // WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. // See the GNU Lesser General Public License for more details. // // You should have received a copy of the License // along with TCPDF. If not, see // <http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT>. // // See LICENSE.TXT file for more information. // ------------------------------------------------------------------- // // Description : This is a PHP class for parsing PDF documents. // //============================================================+ /** * @file * This is a PHP class for parsing PDF documents.<br> * @package com.tecnick.tcpdf * @author Nicola Asuni * @version 1.0.003 */ // include class for decoding filters require_once(dirname(__FILE__).'/include/tcpdf_filters.php'); /** * @class TCPDF_PARSER * This is a PHP class for parsing PDF documents.<br> * @package com.tecnick.tcpdf * @brief This is a PHP class for parsing PDF documents.. * @version 1.0.003 * @author Nicola Asuni - info@tecnick.com */ class TCPDF_PARSER { /** * Raw content of the PDF document. * @private */ private $pdfdata = ''; /** * XREF data. * @protected */ protected $xref = array(); /** * Array of PDF objects. * @protected */ protected $objects = array(); /** * Class object for decoding filters. * @private */ private $FilterDecoders; // ----------------------------------------------------------------------------- /** * Parse a PDF document an return an array of objects. * @param $data (string) PDF data to parse. * @public * @since 1.0.000 (2011-05-24) */ public function __construct($data) { if (empty($data)) { $this->Error('Empty PDF data.'); } $this->pdfdata = $data; // get length $pdflen = strlen($this->pdfdata); // initialize class for decoding filters $this->FilterDecoders = new TCPDF_FILTERS(); // get xref and trailer data $this->xref = $this->getXrefData(); // parse all document objects $this->objects = array(); foreach ($this->xref['xref'] as $obj => $offset) { if (!isset($this->objects[$obj]) AND ($offset > 0)) { // decode only objects with positive offset $this->objects[$obj] = $this->getIndirectObject($obj, $offset, true); } } // release some memory unset($this->pdfdata); $this->pdfdata = ''; } /** * Return an array of parsed PDF document objects. * @return (array) Array of parsed PDF document objects. * @public * @since 1.0.000 (2011-06-26) */ public function getParsedData() { return array($this->xref, $this->objects); } /** * Get Cross-Reference (xref) table and trailer data from PDF document data. * @param $offset (int) xref offset (if know). * @param $xref (array) previous xref array (if any). * @return Array containing xref and trailer data. * @protected * @since 1.0.000 (2011-05-24) */ protected function getXrefData($offset=0, $xref=array()) { if ($offset == 0) { // find last startxref if (preg_match_all('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_SET_ORDER, $offset) == 0) { $this->Error('Unable to find startxref'); } $matches = array_pop($matches); $startxref = $matches[1]; } else { if (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) { // Cross-Reference Stream object $startxref = $offset; } elseif (preg_match('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) { // startxref found $startxref = $matches[1][0]; } else { $this->Error('Unable to find startxref'); } } // check xref position if (strpos($this->pdfdata, 'xref', $startxref) == $startxref) { // Cross-Reference $xref = $this->decodeXref($startxref, $xref); } else { // Cross-Reference Stream $xref = $this->decodeXrefStream($startxref, $xref); } if (empty($xref)) { $this->Error('Unable to find xref'); } return $xref; } /** * Decode the Cross-Reference section * @param $startxref (int) Offset at which the xref section starts. * @param $xref (array) Previous xref array (if any). * @return Array containing xref and trailer data. * @protected * @since 1.0.000 (2011-06-20) */ protected function decodeXref($startxref, $xref=array()) { // extract xref data (object indexes and offsets) $xoffset = $startxref + 5; // initialize object number $obj_num = 0; $offset = $xoffset; while (preg_match('/^([0-9]+)[\s]([0-9]+)[\s]?([nf]?)/im', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) { $offset = (strlen($matches[0][0]) + $matches[0][1]); if ($matches[3][0] == 'n') { // create unique object index: [object number]_[generation number] $index = $obj_num.'_'.intval($matches[2][0]); // check if object already exist if (!isset($xref['xref'][$index])) { // store object offset position $xref['xref'][$index] = intval($matches[1][0]); } ++$obj_num; $offset += 2; } elseif ($matches[3][0] == 'f') { ++$obj_num; $offset += 2; } else { // object number (index) $obj_num = intval($matches[1][0]); } } // get trailer data if (preg_match('/trailer[\s]*<<(.*)>>[\s]*[\r\n]+startxref[\s]*[\r\n]+/isU', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $xoffset) > 0) { $trailer_data = $matches[1][0]; if (!isset($xref['trailer']) OR empty($xref['trailer'])) { // get only the last updated version $xref['trailer'] = array(); // parse trailer_data if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) { $xref['trailer']['size'] = intval($matches[1]); } if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { $xref['trailer']['root'] = intval($matches[1]).'_'.intval($matches[2]); } if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { $xref['trailer']['encrypt'] = intval($matches[1]).'_'.intval($matches[2]); } if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) { $xref['trailer']['info'] = intval($matches[1]).'_'.intval($matches[2]); } if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) { $xref['trailer']['id'] = array(); $xref['trailer']['id'][0] = $matches[1]; $xref['trailer']['id'][1] = $matches[2]; } } if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) { // get previous xref $xref = $this->getXrefData(intval($matches[1]), $xref); } } else { $this->Error('Unable to find trailer'); } return $xref; } /** * Decode the Cross-Reference Stream section * @param $startxref (int) Offset at which the xref section starts. * @param $xref (array) Previous xref array (if any). * @return Array containing xref and trailer data. * @protected * @since 1.0.003 (2013-03-16) */ protected function decodeXrefStream($startxref, $xref=array()) { // try to read Cross-Reference Stream $xrefobj = $this->getRawObject($startxref); $xrefcrs = $this->getIndirectObject($xrefobj[1], $startxref, true); if (!isset($xref['trailer']) OR empty($xref['trailer'])) { // get only the last updated version $xref['trailer'] = array(); $filltrailer = true; } else { $filltrailer = false; } $valid_crs = false; $sarr = $xrefcrs[0][1]; foreach ($sarr as $k => $v) { if (($v[0] == '/') AND ($v[1] == 'Type') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == '/') AND ($sarr[($k +1)][1] == 'XRef'))) { $valid_crs = true; } elseif (($v[0] == '/') AND ($v[1] == 'Index') AND (isset($sarr[($k +1)]))) { // first object number in the subsection $index_first = intval($sarr[($k +1)][1][0][1]); // number of entries in the subsection $index_entries = intval($sarr[($k +1)][1][1][1]); } elseif (($v[0] == '/') AND ($v[1] == 'Prev') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) { // get previous xref offset $prevxref = intval($sarr[($k +1)][1]); } elseif (($v[0] == '/') AND ($v[1] == 'W') AND (isset($sarr[($k +1)]))) { // number of bytes (in the decoded stream) of the corresponding field $wb = array(); $wb[0] = intval($sarr[($k +1)][1][0][1]); $wb[1] = intval($sarr[($k +1)][1][1][1]); $wb[2] = intval($sarr[($k +1)][1][2][1]); } elseif (($v[0] == '/') AND ($v[1] == 'DecodeParms') AND (isset($sarr[($k +1)][1]))) { $decpar = $sarr[($k +1)][1]; foreach ($decpar as $kdc => $vdc) { if (($vdc[0] == '/') AND ($vdc[1] == 'Columns') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) { $columns = intval($decpar[($kdc +1)][1]); } elseif (($vdc[0] == '/') AND ($vdc[1] == 'Predictor') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) { $predictor = intval($decpar[($kdc +1)][1]); } } } elseif ($filltrailer) { if (($v[0] == '/') AND ($v[1] == 'Size') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) { $xref['trailer']['size'] = $sarr[($k +1)][1]; } elseif (($v[0] == '/') AND ($v[1] == 'Root') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'ojbref'))) { $xref['trailer']['root'] = $sarr[($k +1)][1]; } elseif (($v[0] == '/') AND ($v[1] == 'Info') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'ojbref'))) { $xref['trailer']['info'] = $sarr[($k +1)][1]; } elseif (($v[0] == '/') AND ($v[1] == 'ID') AND (isset($sarr[($k +1)]))) { $xref['trailer']['id'] = array(); $xref['trailer']['id'][0] = $sarr[($k +1)][1][0][1]; $xref['trailer']['id'][1] = $sarr[($k +1)][1][1][1]; } } } // decode data if ($valid_crs AND isset($xrefcrs[1][3][0])) { // number of bytes in a row $rowlen = ($columns + 1); // convert the stream into an array of integers $sdata = unpack('C*', $xrefcrs[1][3][0]); // split the rows $sdata = array_chunk($sdata, $rowlen); // initialize decoded array $ddata = array(); // initialize first row with zeros $prev_row = array_fill (0, $rowlen, 0); // for each row apply PNG unpredictor foreach ($sdata as $k => $row) { // initialize new row $ddata[$k] = array(); // get PNG predictor value $predictor = (10 + $row[0]); // for each byte on the row for ($i=1; $i<=$columns; ++$i) { // new index $j = ($i - 1); $row_up = $prev_row[$j]; if ($i == 1) { $row_left = 0; $row_upleft = 0; } else { $row_left = $row[($i - 1)]; $row_upleft = $prev_row[($j - 1)]; } switch ($predictor) { case 10: { // PNG prediction (on encoding, PNG None on all rows) $ddata[$k][$j] = $row[$i]; break; } case 11: { // PNG prediction (on encoding, PNG Sub on all rows) $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff); break; } case 12: { // PNG prediction (on encoding, PNG Up on all rows) $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff); break; } case 13: { // PNG prediction (on encoding, PNG Average on all rows) $ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff); break; } case 14: { // PNG prediction (on encoding, PNG Paeth on all rows) // initial estimate $p = ($row_left + $row_up - $row_upleft); // distances $pa = abs($p - $row_left); $pb = abs($p - $row_up); $pc = abs($p - $row_upleft); $pmin = min($pa, $pb, $pc); // return minumum distance switch ($pmin) { case $pa: { $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff); break; } case $pb: { $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff); break; } case $pc: { $ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff); break; } } break; } default: { // PNG prediction (on encoding, PNG optimum) $this->Error('Unknown PNG predictor'); break; } } } $prev_row = $ddata[$k]; } // end for each row // complete decoding $sdata = array(); // for every row foreach ($ddata as $k => $row) { // initialize new row $sdata[$k] = array(0, 0, 0); if ($wb[0] == 0) { // default type field $sdata[$k][0] = 1; } $i = 0; // count bytes on the row // for every column for ($c = 0; $c < 3; ++$c) { // for every byte on the column for ($b = 0; $b < $wb[$c]; ++$b) { $sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8)); ++$i; } } } $ddata = array(); // fill xref if (isset($index_first)) { $obj_num = $index_first; } else { $obj_num = 0; } foreach ($sdata as $k => $row) { switch ($row[0]) { case 0: { // (f) linked list of free objects ++$obj_num; break; } case 1: { // (n) objects that are in use but are not compressed // create unique object index: [object number]_[generation number] $index = $obj_num.'_'.$row[2]; // check if object already exist if (!isset($xref['xref'][$index])) { // store object offset position $xref['xref'][$index] = $row[1]; } ++$obj_num; break; } case 2: { // compressed objects // $row[1] = object number of the object stream in which this object is stored // $row[2] = index of this object within the object stream $index = $row[1].'_0_'.$row[2]; $xref['xref'][$index] = -1; break; } default: { // null objects break; } } } } // end decoding data if (isset($prevxref)) { // get previous xref $xref = $this->getXrefData($prevxref, $xref); } return $xref; } /** * Get object type, raw value and offset to next object * @param $offset (int) Object offset. * @return array containing object type, raw value and offset to next object * @protected * @since 1.0.000 (2011-06-20) */ protected function getRawObject($offset=0) { $objtype = ''; // object type to be returned $objval = ''; // object value to be returned // 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) $offset += strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $offset); // get first char $char = $this->pdfdata{$offset}; // get object type switch ($char) { case '%': { // \x25 PERCENT SIGN // skip comment and search for next token $next = strcspn($this->pdfdata, "\r\n", $offset); if ($next > 0) { $offset += $next; return $this->getRawObject($this->pdfdata, $offset); } break; } case '/': { // \x2F SOLIDUS // name object $objtype = $char; ++$offset; if (preg_match('/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/', substr($this->pdfdata, $offset, 256), $matches) == 1) { $objval = $matches[1]; // unescaped value $offset += strlen($objval); } break; } case '(': // \x28 LEFT PARENTHESIS case ')': { // \x29 RIGHT PARENTHESIS // literal string object $objtype = $char; ++$offset; $strpos = $offset; if ($char == '(') { $open_bracket = 1; while ($open_bracket > 0) { if (!isset($this->pdfdata{$strpos})) { break; } $ch = $this->pdfdata{$strpos}; switch ($ch) { case '\\': { // REVERSE SOLIDUS (5Ch) (Backslash) // skip next character ++$strpos; break; } case '(': { // LEFT PARENHESIS (28h) ++$open_bracket; break; } case ')': { // RIGHT PARENTHESIS (29h) --$open_bracket; break; } } ++$strpos; } $objval = substr($this->pdfdata, $offset, ($strpos - $offset - 1)); $offset = $strpos; } break; } case '[': // \x5B LEFT SQUARE BRACKET case ']': { // \x5D RIGHT SQUARE BRACKET // array object $objtype = $char; ++$offset; if ($char == '[') { // get array content $objval = array(); do { // get element $element = $this->getRawObject($offset); $offset = $element[2]; $objval[] = $element; } while ($element[0] != ']'); // remove closing delimiter array_pop($objval); } break; } case '<': // \x3C LESS-THAN SIGN case '>': { // \x3E GREATER-THAN SIGN if (isset($this->pdfdata{($offset + 1)}) AND ($this->pdfdata{($offset + 1)} == $char)) { // dictionary object $objtype = $char.$char; $offset += 2; if ($char == '<') { // get array content $objval = array(); do { // get element $element = $this->getRawObject($offset); $offset = $element[2]; $objval[] = $element; } while ($element[0] != '>>'); // remove closing delimiter array_pop($objval); } } else { // hexadecimal string object $objtype = $char; ++$offset; if (($char == '<') AND (preg_match('/^([0-9A-Fa-f]+)[>]/iU', substr($this->pdfdata, $offset), $matches) == 1)) { $objval = $matches[1]; $offset += strlen($matches[0]); } } break; } default: { if (substr($this->pdfdata, $offset, 6) == 'endobj') { // indirect object $objtype = 'endobj'; $offset += 6; } elseif (substr($this->pdfdata, $offset, 4) == 'null') { // null object $objtype = 'null'; $offset += 4; $objval = 'null'; } elseif (substr($this->pdfdata, $offset, 4) == 'true') { // boolean true object $objtype = 'boolean'; $offset += 4; $objval = 'true'; } elseif (substr($this->pdfdata, $offset, 5) == 'false') { // boolean false object $objtype = 'boolean'; $offset += 5; $objval = 'false'; } elseif (substr($this->pdfdata, $offset, 6) == 'stream') { // start stream object $objtype = 'stream'; $offset += 6; if (preg_match('/^([\r\n]+)/isU', substr($this->pdfdata, $offset), $matches) == 1) { $offset += strlen($matches[0]); } if (preg_match('/([\r\n]*endstream)/isU', substr($this->pdfdata, $offset), $matches, PREG_OFFSET_CAPTURE) == 1) { $objval = substr($this->pdfdata, $offset, $matches[0][1]); $offset += $matches[0][1]; } } elseif (substr($this->pdfdata, $offset, 9) == 'endstream') { // end stream object $objtype = 'endstream'; $offset += 9; } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) { // indirect object reference $objtype = 'ojbref'; $offset += strlen($matches[0]); $objval = intval($matches[1]).'_'.intval($matches[2]); } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) { // object start $objtype = 'ojb'; $objval = intval($matches[1]).'_'.intval($matches[2]); $offset += strlen ($matches[0]); } elseif (($numlen = strspn($this->pdfdata, '+-.0123456789', $offset)) > 0) { // numeric object $objtype = 'numeric'; $objval = substr($this->pdfdata, $offset, $numlen); $offset += $numlen; } break; } } return array($objtype, $objval, $offset); } /** * Get content of indirect object. * @param $obj_ref (string) Object number and generation number separated by underscore character. * @param $offset (int) Object offset. * @param $decoding (boolean) If true decode streams. * @return array containing object data. * @protected * @since 1.0.000 (2011-05-24) */ protected function getIndirectObject($obj_ref, $offset=0, $decoding=true) { $obj = explode('_', $obj_ref); if (($obj === false) OR (count($obj) != 2)) { $this->Error('Invalid object reference: '.$obj); return; } $objref = $obj[0].' '.$obj[1].' obj'; if (strpos($this->pdfdata, $objref, $offset) != $offset) { // an indirect reference to an undefined object shall be considered a reference to the null object return array('null', 'null', $offset); } // starting position of object content $offset += strlen($objref); // get array of object content $objdata = array(); $i = 0; // object main index do { // get element $element = $this->getRawObject($offset); $offset = $element[2]; // decode stream using stream's dictionary information if ($decoding AND ($element[0] == 'stream') AND (isset($objdata[($i - 1)][0])) AND ($objdata[($i - 1)][0] == '<<')) { $element[3] = $this->decodeStream($objdata[($i - 1)][1], substr($element[1], 1)); } $objdata[$i] = $element; ++$i; } while ($element[0] != 'endobj'); // remove closing delimiter array_pop($objdata); // return raw object content return $objdata; } /** * Get the content of object, resolving indect object reference if necessary. * @param $obj (string) Object value. * @return array containing object data. * @protected * @since 1.0.000 (2011-06-26) */ protected function getObjectVal($obj) { if ($obj[0] == 'objref') { // reference to indirect object if (isset($this->objects[$obj[1]])) { // this object has been already parsed return $this->objects[$obj[1]]; } elseif (isset($this->xref[$obj[1]])) { // parse new object $this->objects[$obj[1]] = $this->getIndirectObject($obj[1], $this->xref[$obj[1]], false); return $this->objects[$obj[1]]; } } return $obj; } /** * Decode the specified stream. * @param $sdic (array) Stream's dictionary array. * @param $stream (string) Stream to decode. * @return array containing decoded stream data and remaining filters. * @protected * @since 1.0.000 (2011-06-22) */ protected function decodeStream($sdic, $stream) { // get stream lenght and filters $slength = strlen($stream); if ($slength <= 0) { return array('', array()); } $filters = array(); foreach ($sdic as $k => $v) { if ($v[0] == '/') { if (($v[1] == 'Length') AND (isset($sdic[($k + 1)])) AND ($sdic[($k + 1)][0] == 'numeric')) { // get declared stream lenght $declength = intval($sdic[($k + 1)][1]); if ($declength < $slength) { $stream = substr($stream, 0, $declength); $slength = $declength; } } elseif (($v[1] == 'Filter') AND (isset($sdic[($k + 1)]))) { // resolve indirect object $objval = $this->getObjectVal($sdic[($k + 1)]); if ($objval[0] == '/') { // single filter $filters[] = $objval[1]; } elseif ($objval[0] == '[') { // array of filters foreach ($objval[1] as $flt) { if ($flt[0] == '/') { $filters[] = $flt[1]; } } } } } } // decode the stream $remaining_filters = array(); foreach ($filters as $filter) { if (in_array($filter, $this->FilterDecoders->getAvailableFilters())) { $stream = $this->FilterDecoders->decodeFilter($filter, $stream); } else { // add missing filter to array $remaining_filters[] = $filter; } } return array($stream, $remaining_filters); } /** * This method is automatically called in case of fatal error; it simply outputs the message and halts the execution. * @param $msg (string) The error message * @public * @since 1.0.000 (2011-05-23) */ public function Error($msg) { // exit program and print error die('<strong>TCPDF_PARSER ERROR: </strong>'.$msg); } } // END OF TCPDF_PARSER CLASS //============================================================+ // END OF FILE //============================================================+
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