PHP YIELD使读取大文件

   /**
     * [getLines 逐行读取文件中数据]
     * @author Jhou Shuai
     * @param  [type] $file [description]
     * @return [type]       [description]
     */
    public function getLines($file) {
        $f = fopen($file, 'r');
        try {
            while ($line = fgets($f)) {
                yield $line;
            }
        } finally {
            fclose($f);
        }
    }

   foreach ($this->getLines('mytest.txt') as $n => $line) {
       echo $line;
   }
  
   
    /**
     * [_parse CSV文件读取]
     * @author Jhou Shuai
     * @datetime 2018-12-20T13:48:03+0800
     */
    private function _parse($filename, $keypos = 0) {
        $data = array();
        if (($handle = fopen($filename, "r")) !== FALSE) {
            while (($line = fgetcsv($handle, 1000, ",")) !== FALSE) {
                yield $line;
            }
            fclose($handle);
        }
    }

     $file = '/var/www/xxxx/data/xxxx.csv';
     foreach ($this->_parse($file, 0) as $line) {
            $idcard = preg_replace('# #', '', trim($line[2]));
            $idcard = strtoupper($idcard);
     }