find_time_window_lower_bound

flow::expr::utils

Function find_time_window_lower_bound 

Source 
pub fn find_time_window_lower_bound(
    expr: &ScalarExpr,
    ts_col_idx: usize,
    current: Timestamp,
) -> Result<Option<Timestamp>>
Expand description

Find the lower bound of time window in given expr and current timestamp.

i.e. for current="2021-07-01 00:01:01.000" and expr=date_bin(INTERVAL '5 minutes', ts) as time_window and ts_col=ts, return Some("2021-07-01 00:00:00.000") since it’s the lower bound of current time window given the current timestamp

if return None, meaning this time window have no lower bound