Swoole\Mmap::open
  (PECL swoole >= 1.9.0)
Swoole\Mmap::open — Map a file into memory and return the stream resource which can be used by PHP stream operations.
  
 
  说明
  
   public static Swoole\Mmap::open(
string $filename, 
string $size = ?, 
string $offset = ?): 
ReturnType