在SQLITE源码中看到这样一行代码,不懂啥意思!

int sqlite3_config(int op, ...){

/*

** Configuration settings for an individual database connection

*/

int sqlite3_db_config(sqlite3 *db, int op, ...){

  va_list ap;

  int rc;

  va_start(ap, op);

  switch( op ){

    case SQLITE_DBCONFIG_LOOKASIDE: {

      void *pBuf = va_arg(ap, void*);

      int sz = va_arg(ap, int);

      int cnt = va_arg(ap, int);

      rc = setupLookaside(db, pBuf, sz, cnt);

      break;

    }

    default: {

      rc = SQLITE_ERROR;

      break;

    }

  }

  va_end(ap);

  return rc;

}