File indexing completed on 2024-12-22 05:36:56

 <?php
 /**
  * Zend Framework
  *
  * LICENSE
  *
  * This source file is subject to the new BSD license that is bundled
  * with this package in the file LICENSE.txt.
  * It is also available through the world-wide-web at this URL:
  * http://framework.zend.com/license/new-bsd
  * If you did not receive a copy of the license and are unable to
  * obtain it through the world-wide-web, please send an email
  * to license@zend.com so we can send you a copy immediately.
  *
  * @category   Zend
  * @package    Zend_Pdf
  * @subpackage FileParser
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  * @version    $Id$
  */
 
 /**
  * Abstract helper class for {@link Zend_Pdf_FileParser} that provides the
  * data source for parsing.
  *
  * Concrete subclasses allow for parsing of in-memory, filesystem, and other
  * sources through a common API. These subclasses also take care of error
  * handling and other mundane tasks.
  *
  * Subclasses must implement at minimum {@link __construct()},
  * {@link __destruct()}, {@link readBytes()}, and {@link readAllBytes()}.
  * Subclasses should also override {@link moveToOffset()} and
  * {@link __toString()} as appropriate.
  *
  * @package    Zend_Pdf
  * @subpackage FileParser
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  */
 abstract class Zend_Pdf_FileParserDataSource
 {
   /**** Instance Variables ****/
 
 
     /**
      * Total size in bytes of the data source.
      * @var integer
      */
     protected $_size = 0;
 
     /**
      * Byte offset of the current read position within the data source.
      * @var integer
      */
     protected $_offset = 0;
 
 
 
   /**** Public Interface ****/
 
 
   /* Abstract Methods */
 
     /**
      * Object destructor. Closes the data source.
      *
      * May also perform cleanup tasks such as deleting temporary files.
      */
     abstract public function __destruct();
 
     /**
      * Returns the specified number of raw bytes from the data source at the
      * byte offset of the current read position.
      *
      * Must advance the read position by the number of bytes read by updating
      * $this->_offset.
      *
      * Throws an exception if there is insufficient data to completely fulfill
      * the request or if an error occurs.
      *
      * @param integer $byteCount Number of bytes to read.
      * @return string
      * @throws Zend_Pdf_Exception
      */
     abstract public function readBytes($byteCount);
 
     /**
      * Returns the entire contents of the data source as a string.
      *
      * This method may be called at any time and so must preserve the byte
      * offset of the read position, both through $this->_offset and whatever
      * other additional pointers (such as the seek position of a file pointer)
      * that might be used.
      *
      * @return string
      */
     abstract public function readAllBytes();
 
 
   /* Object Magic Methods */
 
     /**
      * Returns a description of the object for debugging purposes.
      *
      * Subclasses should override this method to provide a more specific
      * description of the actual object being represented.
      *
      * @return string
      */
     public function __toString()
     {
         return get_class($this);
     }
 
 
   /* Accessors */
 
     /**
      * Returns the byte offset of the current read position within the data
      * source.
      *
      * @return integer
      */
     public function getOffset()
     {
         return $this->_offset;
     }
 
     /**
      * Returns the total size in bytes of the data source.
      *
      * @return integer
      */
     public function getSize()
     {
         return $this->_size;
     }
 
 
   /* Primitive Methods */
 
     /**
      * Moves the current read position to the specified byte offset.
      *
      * Throws an exception you attempt to move before the beginning or beyond
      * the end of the data source.
      *
      * If a subclass needs to perform additional tasks (such as performing a
      * fseek() on a filesystem source), it should do so after calling this
      * parent method.
      *
      * @param integer $offset Destination byte offset.
      * @throws Zend_Pdf_Exception
      */
     public function moveToOffset($offset)
     {
         if ($this->_offset == $offset) {
             return;    // Not moving; do nothing.
         }
         if ($offset < 0) {
             // require_once 'Zend/Pdf/Exception.php';
             throw new Zend_Pdf_Exception('Attempt to move before start of data source',
                                          Zend_Pdf_Exception::MOVE_BEFORE_START_OF_FILE);
         }
         if ($offset >= $this->_size) {    // Offsets are zero-based.
             // require_once 'Zend/Pdf/Exception.php';
             throw new Zend_Pdf_Exception('Attempt to move beyond end of data source',
                                          Zend_Pdf_Exception::MOVE_BEYOND_END_OF_FILE);
         }
         $this->_offset = $offset;
     }
 
     /**
      * Shifts the current read position within the data source by the specified
      * number of bytes.
      *
      * You may move forward (positive numbers) or backward (negative numbers).
      * Throws an exception you attempt to move before the beginning or beyond
      * the end of the data source.
      *
      * @param integer $byteCount Number of bytes to skip.
      * @throws Zend_Pdf_Exception
      */
     public function skipBytes($byteCount)
     {
         $this->moveToOffset($this->_offset + $byteCount);
     }
 }