125         $fp = null;
138             $fp = fopen($file, 'rb'); // "file pointer"
139             if ($fp === false) {
142             fseek($fp, 0, SEEK_END);
143             $eof = ftell($fp);
149                 $finger = $this->getNewlinepointer($fp, $finger);
150                 $tmp = fgets($fp);
171                 fclose($fp);
175             $lines = $this->readChunk($fp, $head, $tail);
177         return [$fp, $lines, $head, $tail, $eof];
184      * @param resource $fp resource file pointer
189     protected function readChunk($fp, $head, $tail)  argument
194         fseek($fp, $head);
195         while ($got < $chunk_size && !feof($fp)) {
196             $tmp = @fread($fp, max(min($this->chunk_size, $chunk_size - $got), 0));
211      * @param resource $fp file pointer
215     protected function getNewlinepointer($fp, $finger)  argument
217         fseek($fp, $finger);
220             fgets($fp); // slip the finger forward to a new line
221             $nl = ftell($fp);
229      * @param resource $fp file pointer
238     protected function readAdjacentChunk($fp, $head, $tail, $direction)  argument
240         if (!$fp) return [[], $head, $tail];
246             $tail = $this->getNewlinepointer($fp, $tail);
252                 $nl = $this->getNewlinepointer($fp, $head);
264         $lines = $this->readChunk($fp, $head, $tail);