* Creates an instance of this class
*
* @param $pointerInstance An instance of a InputOutputPointer class
+ * @param $blockInstance An instance of a CalculatableBlock class
* @return $iteratorInstance An instance of a Iterator class
*/
- public final static function createFileIoIterator (InputOutputPointer $pointerInstance) {
+ public final static function createFileIoIterator (InputOutputPointer $pointerInstance, CalculatableBlock $blockInstance) {
// Get new instance
$iteratorInstance = new FileIoIterator();
// Set the instance here
$iteratorInstance->setPointerInstance($pointerInstance);
+ // Set the block instance here
+ $iteratorInstance->setBlockInstance($blockInstance);
+
// Return the prepared instance
return $iteratorInstance;
}
* Checks wether the current entry is valid (not at the end of the file).
* This method will return TRUE if an emptied (nulled) entry has been found.
*
- * @return void
+ * @return $isValid Whether the next entry is valid
*/
public function valid () {
- $this->partialStub('Please implement this method.');
+ // First calculate minimum block length
+ $length = $this->getBlockInstance()->caluclateMinimumBlockLength();
+
+ // Short be more than zero!
+ assert($length > 0);
+
+ // Get current seek position
+ $seekPosition = $this->key();
+
+ // Then try to read it
+ $data = $this->read($length);
+
+ // If some bytes could be read, all is fine
+ $isValid = ((is_string($data)) && (strlen($data) > 0));
+
+ // Seek back to old position
+ $this->seek($seekPosition);
+
+ // Return result
+ return $isValid;
}
/**