udf_1_session_change_flag.py

# UDF-1
# make a array for session change flag
# for all rows x
# set the flag if user_sk[x]!=user_sk[x-1] or  tstamp_inSec[x] - tstamp_inSec[x-1] > 60 minutes
@cuda.jit
def make_session_change_flag_kernel(
    user_sk, tstamp_inSec, session_change_flag, time_out
):
    gid = cuda.grid(1)
    if 0 < gid < len(wcs_user_sk):
        if (
            user_sk[gid] != user_sk[gid - 1]
            or tstamp_inSec[gid] - tstamp_inSec[gid - 1] > time_out
        ):
            session_change_flag[gid] = np.int32(1)
        else:
            session_change_flag[gid] = np.int32(0)
    else:
        session_change_flag[gid] = np.int32(1)