/**
* Get next generation number for free object
*
* @param integer $objNum
* @return unknown
*/
public function getNewGeneration($objNum)
{
if (isset($this->_usedObjects[$objNum])) {
throw new Exception\CorruptedPdfException('Object is not free');
}
if (isset($this->_generations[$objNum])) {
return $this->_generations[$objNum];
}
if (isset($this->_parent)) {
return $this->_parent->getNewGeneration($objNum);
}
throw new Exception\CorruptedPdfException('Object not found.');
}
/**
* Load XReference table and referenced objects
*
* @param integer $offset
* @throws \ZendPdf\Exception\ExceptionInterface
* @return \ZendPdf\Trailer\Parsed
*/
private function _loadXRefTable($offset)
{
$this->_stringParser->offset = $offset;
$refTable = new IndirectObjectReference\ReferenceTable();
$context = new IndirectObjectReference\Context($this->_stringParser, $refTable);
$this->_stringParser->setContext($context);
$nextLexeme = $this->_stringParser->readLexeme();
if ($nextLexeme == 'xref') {
/**
* Common cross-reference table
*/
$this->_stringParser->skipWhiteSpace();
while (($nextLexeme = $this->_stringParser->readLexeme()) != 'trailer') {
if (!ctype_digit($nextLexeme)) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference table subheader values must contain only digits.', $this->_stringParser->offset - strlen($nextLexeme)));
}
$objNum = (int) $nextLexeme;
$refCount = $this->_stringParser->readLexeme();
if (!ctype_digit($refCount)) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference table subheader values must contain only digits.', $this->_stringParser->offset - strlen($refCount)));
}
$this->_stringParser->skipWhiteSpace();
while ($refCount > 0) {
$objectOffset = substr($this->_stringParser->data, $this->_stringParser->offset, 10);
if (!ctype_digit($objectOffset)) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Offset must contain only digits.', $this->_stringParser->offset));
}
// Force $objectOffset to be treated as decimal instead of octal number
for ($numStart = 0; $numStart < strlen($objectOffset) - 1; $numStart++) {
if ($objectOffset[$numStart] != '0') {
break;
}
}
$objectOffset = substr($objectOffset, $numStart);
$this->_stringParser->offset += 10;
if (strpos("\t\n\f\r ", $this->_stringParser->data[$this->_stringParser->offset]) === false) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));
}
$this->_stringParser->offset++;
$genNumber = substr($this->_stringParser->data, $this->_stringParser->offset, 5);
if (!ctype_digit($objectOffset)) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Offset must contain only digits.', $this->_stringParser->offset));
}
// Force $objectOffset to be treated as decimal instead of octal number
for ($numStart = 0; $numStart < strlen($genNumber) - 1; $numStart++) {
if ($genNumber[$numStart] != '0') {
break;
}
}
$genNumber = substr($genNumber, $numStart);
$this->_stringParser->offset += 5;
if (strpos("\t\n\f\r ", $this->_stringParser->data[$this->_stringParser->offset]) === false) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));
}
$this->_stringParser->offset++;
$inUseKey = $this->_stringParser->data[$this->_stringParser->offset];
$this->_stringParser->offset++;
switch ($inUseKey) {
case 'f':
// free entry
unset($this->_refTable[$objNum . ' ' . $genNumber . ' R']);
$refTable->addReference($objNum . ' ' . $genNumber . ' R', $objectOffset, false);
break;
case 'n':
// in-use entry
$refTable->addReference($objNum . ' ' . $genNumber . ' R', $objectOffset, true);
}
if (!DataParser::isWhiteSpace(ord($this->_stringParser->data[$this->_stringParser->offset]))) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));
}
$this->_stringParser->offset++;
if (!DataParser::isWhiteSpace(ord($this->_stringParser->data[$this->_stringParser->offset]))) {
throw new Exception\CorruptedPdfException(sprintf('PDF file cross-reference table syntax error. Offset - 0x%X. Value separator must be white space.', $this->_stringParser->offset));
}
$this->_stringParser->offset++;
$refCount--;
$objNum++;
}
}
$trailerDictOffset = $this->_stringParser->offset;
$trailerDict = $this->_stringParser->readElement();
if (!$trailerDict instanceof InternalType\DictionaryObject) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Dictionary expected after \'trailer\' keyword.', $trailerDictOffset));
}
} else {
$xrefStream = $this->_stringParser->getObject($offset, $context);
if (!$xrefStream instanceof InternalType\StreamObject) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference stream expected.', $offset));
}
$trailerDict = $xrefStream->dictionary;
if ($trailerDict->Type->value != 'XRef') {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross-reference stream object must have /Type property assigned to /XRef.', $offset));
}
if ($trailerDict->W === null || $trailerDict->W->getType() != InternalType\AbstractTypeObject::TYPE_ARRAY) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross reference stream dictionary doesn\'t have W entry or it\'s not an array.', $offset));
}
$entryField1Size = $trailerDict->W->items[0]->value;
$entryField2Size = $trailerDict->W->items[1]->value;
$entryField3Size = $trailerDict->W->items[2]->value;
if ($entryField2Size == 0 || $entryField3Size == 0) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Wrong W dictionary entry. Only type field of stream entries has default value and could be zero length.', $offset));
}
$xrefStreamData = $xrefStream->value;
if ($trailerDict->Index !== null) {
if ($trailerDict->Index->getType() != InternalType\AbstractTypeObject::TYPE_ARRAY) {
throw new Exception\CorruptedPdfException(sprintf('PDF file syntax error. Offset - 0x%X. Cross reference stream dictionary Index entry must be an array.', $offset));
}
$sections = count($trailerDict->Index->items) / 2;
} else {
$sections = 1;
}
$streamOffset = 0;
$size = $entryField1Size + $entryField2Size + $entryField3Size;
$entries = strlen($xrefStreamData) / $size;
for ($count = 0; $count < $sections; $count++) {
if ($trailerDict->Index !== null) {
$objNum = $trailerDict->Index->items[$count * 2]->value;
$entries = $trailerDict->Index->items[$count * 2 + 1]->value;
} else {
$objNum = 0;
$entries = $trailerDict->Size->value;
}
for ($count2 = 0; $count2 < $entries; $count2++) {
if ($entryField1Size == 0) {
$type = 1;
} elseif ($entryField1Size == 1) {
// Optimyze one-byte field case
$type = ord($xrefStreamData[$streamOffset++]);
} else {
$type = DataParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField1Size);
$streamOffset += $entryField1Size;
}
if ($entryField2Size == 1) {
// Optimyze one-byte field case
$field2 = ord($xrefStreamData[$streamOffset++]);
} else {
$field2 = DataParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField2Size);
$streamOffset += $entryField2Size;
}
if ($entryField3Size == 1) {
// Optimyze one-byte field case
$field3 = ord($xrefStreamData[$streamOffset++]);
} else {
$field3 = DataParser::parseIntFromStream($xrefStreamData, $streamOffset, $entryField3Size);
$streamOffset += $entryField3Size;
}
switch ($type) {
case 0:
// Free object
$refTable->addReference($objNum . ' ' . $field3 . ' R', $field2, false);
// Debug output:
// echo "Free object - $objNum $field3 R, next free - $field2\n";
break;
case 1:
// In use object
$refTable->addReference($objNum . ' ' . $field3 . ' R', $field2, true);
// Debug output:
// echo "In-use object - $objNum $field3 R, offset - $field2\n";
break;
case 2:
// Object in an object stream
// Debug output:
// echo "Compressed object - $objNum 0 R, object stream - $field2 0 R, offset - $field3\n";
break;
}
$objNum++;
}
}
// $streamOffset . ' ' . strlen($xrefStreamData) . "\n";
// "$entries\n";
throw new Exception\NotImplementedException('Cross-reference streams are not supported yet.');
}
$trailerObj = new Trailer\Parsed($trailerDict, $context);
if ($trailerDict->Prev instanceof InternalType\NumericObject || $trailerDict->Prev instanceof InternalType\IndirectObjectReference) {
$trailerObj->setPrev($this->_loadXRefTable($trailerDict->Prev->value));
$context->getRefTable()->setParent($trailerObj->getPrev()->getRefTable());
}
/**
* We set '/Prev' dictionary property to the current cross-reference section offset.
* It doesn't correspond to the actual data, but is true when trailer will be used
* as a trailer for next generated PDF section.
*/
$trailerObj->Prev = new InternalType\NumericObject($offset);
return $trailerObj;
}
