// Helper method for conn pools to convert errors
func getOrPanic(pool *dbconnpool.ConnectionPool) dbconnpool.PoolConnection {
	conn, err := pool.Get()
	if err == nil {
		return conn
	}
	if err == dbconnpool.CONN_POOL_CLOSED_ERR {
		panic(connPoolClosedErr)
	}
	panic(NewTabletErrorSql(FATAL, err))
}

func (rqc *RequestContext) getConn(pool *dbconnpool.ConnectionPool) dbconnpool.PoolConnection {
	start := time.Now()
	timeout, err := rqc.deadline.Timeout()
	if err != nil {
		panic(NewTabletError(FAIL, "getConn: %v", err))
	}
	conn, err := pool.Get(timeout)
	switch err {
	case nil:
		rqc.logStats.WaitingForConnection += time.Now().Sub(start)
		return conn
	case dbconnpool.CONN_POOL_CLOSED_ERR:
		panic(connPoolClosedErr)
	}
	panic(NewTabletErrorSql(FATAL, err))
}

// getPoolReconnect gets a connection from a pool, tests it, and reconnects if
// it gets errno 2006.
func getPoolReconnect(ctx context.Context, pool *dbconnpool.ConnectionPool) (dbconnpool.PoolConnection, error) {
	conn, err := pool.Get(ctx)
	if err != nil {
		return conn, err
	}
	// Run a test query to see if this connection is still good.
	if _, err := conn.ExecuteFetch("SELECT 1", 1, false); err != nil {
		// If we get "MySQL server has gone away (errno 2006)", try to reconnect.
		if sqlErr, ok := err.(*sqldb.SQLError); ok && sqlErr.Number() == 2006 {
			if err := conn.Reconnect(); err != nil {
				conn.Recycle()
				return conn, err
			}
		}
	}
	return conn, nil
}