192     function getData($length = -1)  argument
194         if ($length == -1) {
195             $length = $this->_nbBytesLeft;
197             $length = min($length, $this->_nbBytesLeft);
199         if ($length == 0) {
202             $this->_nbBytesLeft -= $length;
203             $data = $this->source->getData($length);
207             if (strlen($data) != $length) {
217     function skip($length = -1)  argument
219         if ($length == -1) {
220             $length = $this->_nbBytesLeft;
222             $length = min($length, $this->_nbBytesLeft);
224         if ($length == 0) {
227             $this->_nbBytesLeft -= $length;
228             $skipped = $this->source->skip($length);
232             if ($skipped != $length) {
242     function rewind($length = -1)  argument
244         if ($length == -1) {
245             $length = $this->_currentStat[7] - $this->_nbBytesLeft;
247             $length = min($length, $this->_currentStat[7] - $this->_nbBytesLeft);
249         if ($length == 0) {
252             $rewinded = $this->source->rewind($length);
337         foreach ($blocks as $length) {
339                 $data .= $this->getData($length);
341                 $this->skip($length);