/**
* Object constructor.
*
* Verifies that the data source has been properly initialized.
*
* @param \ZendPdf\BinaryParser\DataSource\AbstractDataSource $dataSource
* @throws \ZendPdf\Exception\ExceptionInterface
*/
public function __construct(DataSource\AbstractDataSource $dataSource)
{
if ($dataSource->getSize() == 0) {
throw new Exception\BinaryParserException('The data source has not been properly initialized');
}
$this->_dataSource = $dataSource;
}
/**
* Reads the Pascal string from the binary file at the current byte offset.
*
* The length of the Pascal string is determined by reading the length bytes
* which preceed the character data. You must supply the desired resulting
* character set.
*
* Advances the offset by the number of bytes read. Throws an exception if
* an error occurs.
*
* @param string $characterSet (optional) Desired resulting character set.
* You may use any character set supported by {@link iconv()}. If omitted,
* uses 'current locale'.
* @param integer $lengthBytes (optional) Number of bytes that make up the
* length. Default is 1.
* @return string
* @throws \ZendPdf\Exception\ExceptionInterface
*/
public function readStringPascal($characterSet = '', $lengthBytes = 1)
{
$byteCount = $this->readUInt($lengthBytes);
if ($byteCount == 0) {
return '';
}
$bytes = $this->_dataSource->readBytes($byteCount);
if ($characterSet == 'ASCII') {
return $bytes;
}
return iconv('ASCII', $characterSet, $bytes);
}
/**
* Seeks the file read position to the specified byte offset.
*
* Throws an exception if the file pointer cannot be moved or if it is
* moved beyond EOF (end of file).
*
* @param integer $offset Destination byte offset.
* @throws \ZendPdf\Exception\ExceptionInterface
*/
public function moveToOffset($offset)
{
if ($this->_offset == $offset) {
return;
// Not moving; do nothing.
}
parent::moveToOffset($offset);
$result = @fseek($this->_fileResource, $offset, SEEK_SET);
if ($result !== 0) {
throw new Exception\IOException('Error while setting new file position');
}
if (feof($this->_fileResource)) {
throw new Exception\IOException('Moved beyond the end of the file');
}
}
