public function stream_seek($offset, $whence = SEEK_SET)
{
$return = false;
switch ($whence) {
case SEEK_SET:
$newPosition = $offset;
break;
case SEEK_CUR:
$newPosition = $this->position + $offset;
break;
case SEEK_END:
$newPosition = $this->unencryptedSize + $offset;
break;
default:
return $return;
}
if ($newPosition > $this->unencryptedSize || $newPosition < 0) {
return $return;
}
$newFilePosition = floor($newPosition / $this->unencryptedBlockSize) * $this->util->getBlockSize() + $this->headerSize;
$oldFilePosition = parent::stream_tell();
if ($this->parentStreamSeek($newFilePosition)) {
$this->parentStreamSeek($oldFilePosition);
$this->flush();
$this->parentStreamSeek($newFilePosition);
$this->position = $newPosition;
$return = true;
}
return $return;
}
/**
* write block to file
*/
protected function flush()
{
// write to disk only when writeFlag was set to 1
if ($this->writeFlag) {
// Disable the file proxies so that encryption is not
// automatically attempted when the file is written to disk -
// we are handling that separately here and we don't want to
// get into an infinite loop
$encrypted = $this->encryptionModule->encrypt($this->cache);
parent::stream_write($encrypted);
$this->writeFlag = false;
$this->size = max($this->size, parent::stream_tell());
}
// always empty the cache (otherwise readCache() will not fill it with the new block)
$this->cache = '';
}
