* @copyright Copyright (c) 2006-2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Rev$
*/
class Reader
{
/** @var resource */
private $_fd;
/** @var integer */
private $_size;
/**
* Constructs the Reader class with given file.
*
* @param string $filename The path to the file.
* @param string $mode The type of access.
* @throws Reader_Exception if the file cannot be read.
*/
public function __construct($filename, $mode = "rb")
{
if (($this->_fd = fopen($filename, $mode)) === false)
throw new Reader_Exception("Unable to open file:" . $filename);
fseek($this->_fd, 0, SEEK_END);
$this->_size = ftell($this->_fd);
fseek($this->_fd, 0);
}
/**
* Closes the file.
*/
public function __destruct()
{
@fclose($this->_fd);
}
/**
* Checks whether there is more to be read in the file. Returns
* true if the end of the file has not yet been reached;
* false otherwise.
*
* @return boolean
*/
public function available()
{
return $this->getOffset() < $this->_size;
}
/**
* Jumps size amount of bytes in the file stream.
*
* @param integer $size The amount of bytes.
* @return void
* @throws Reader_Exception if size attribute is negative.
*/
public function skip($size)
{
if ($size < 0)
throw new Reader_Exception("Invalid argument");
if ($size == 0)
return;
fseek($this->_fd, $size, SEEK_CUR);
}
/**
* Reads length amount of bytes from the file stream.
*
* @param integer $length The amount of bytes.
* @return string
* @throws Reader_Exception if length attribute is negative.
*/
public function read($length)
{
if ($length < 0)
throw new Reader_Exception("Invalid argument");
if ($length == 0)
return "";
return fread($this->_fd, $length);
}
/**
* Returns the current point of operation.
*
* @return integer
*/
public function getOffset()
{
return ftell($this->_fd);
}
/**
* Sets the point of operation, ie the cursor offset value. The offset can
* also be set to a negative value when it is interpreted as an offset from
* the end of the file instead of the beginning.
*
* @param integer $offset The new point of operation.
* @return void
*/
public function setOffset($offset)
{
fseek($this->_fd, $offset < 0 ? $this->_size + $offset : $offset);
}
/**
* Returns the file size in bytes.
*
* @return integer
*/
public function getSize()
{
return $this->_size;
}
/**
* Magic function so that $obj->value will work.
*
* @param string $name The field name.
* @return mixed
*/
public function __get($name) {
if (method_exists($this, "get" . ucfirst(strtolower($name))))
return call_user_func(array($this, "get" . ucfirst(strtolower($name))));
else throw new Reader_Exception("Unknown field: " . $name);
}
/**
* Magic function so that assignments with $obj->value will work.
*
* @param string $name The field name.
* @param string $value The field value.
* @return mixed
*/
public function __set($name, $value) {
if (method_exists($this, "set" . ucfirst(strtolower($name))))
call_user_func
(array($this, "set" . ucfirst(strtolower($name))), $value);
else throw new Reader_Exception("Unknown field: " . $name);
}
/**
* Magic function to delegate the call to helper methods of
* Transform class to transform read data in another format.
*
* The read data length is determined from the helper method name. For methods
* where arbitrary data lengths are accepted a parameter can be used to
* specify the length.
*
* @param string $method The method to be called.
* @param string $params The parameters should the function accept them.
* @return mixed
* @throws Reader_Exception if no such transformer is implemented
*/
public function __call($method, $params) {
$chunks = array();
if (preg_match
("/read([a-z]{3,6})?(\d{1,2})?(?:LE|BE)?/i", $method, $chunks) &&
method_exists("Transform", preg_replace("/^read/", "from", $method))) {
return call_user_func
(array("Transform", preg_replace("/^read/", "from", $method)),
$this->read(preg_match("/String|(?:H|L)Hex/", $chunks[1]) ?
(isset($params[0]) ? $params[0] : 1) :
($chunks[1] == "GUID" ? 16 : $chunks[2] / 8)));
} else throw new Reader_Exception("Unknown method: " . $method);
}
}