Method setup_reading

sql/sql_lifo_buffer.h:105–109

Specify where read() should store pointers to read data, as well as read data size. The sizes must match those passed to setup_writing(). */

    data size. The sizes must match those passed to setup_writing().
  */
  void setup_reading(size_t len1, size_t len2)
  {
    DBUG_ASSERT(len1 == size1);
    DBUG_ASSERT(len2 == size2);
  }
  
  bool can_write()
  {