write_gtfs is taking a bit too long

[ipeagit]

write_gtfs is taking a bit too long

[dhersz]

And that will probably speed read_gtfs() up significantly as well.

[dhersz]

Fixed that in d920ba4.

Now time columns are read as strings andconverted to seconds after midnight (as int) when needed.

This significantly speed GTFS reading and writing.

Here are some timings:

microbenchmark::microbenchmark(
    gtfs <- read_gtfs(data_path),
    gtfs_tidy <- tidytransit::read_gtfs(data_path),
    gtfs_2gps <- gtfs2gps::read_gtfs(data_path),
    times = 5L
)
#> Unit: milliseconds
#>                                           expr       min        lq      mean    median        uq       max neval
#>                   gtfs <- read_gtfs(data_path)  747.7385  787.6492  798.1753  807.7225  813.6713  834.0952     5
#> gtfs_tidy <- tidytransit::read_gtfs(data_path) 1680.2482 1913.6716 2174.9585 2017.0233 2036.0840 3227.7655     5
#>    gtfs_2gps <- gtfs2gps::read_gtfs(data_path) 1968.6259 1970.1558 2278.7080 1996.7162 2523.9983 2934.0436     5

tmp_dir <- tempdir()
tmp_file1 <- tempfile(pattern = "gtfs", tmpdir = tmp_dir, fileext = ".zip")
tmp_file2 <- tempfile(pattern = "gtfs", tmpdir = tmp_dir, fileext = ".zip")
tmp_file3 <- tempfile(pattern = "gtfs", tmpdir = tempdir(), fileext = ".zip")

microbenchmark::microbenchmark(
    write_gtfs(gtfs, tmp_file1),
    tidytransit::write_gtfs(gtfs_tidy, tmp_file2),
    gtfs2gps::write_gtfs(gtfs_2gps, tmp_file3),
    times = 5L
)
#> Unit: seconds
#>                                          expr      min       lq     mean  median       uq      max neval
#>                   write_gtfs(gtfs, tmp_file1) 2.672873 2.678202 3.043181 2.70489 2.801637 4.358303     5
#> tidytransit::write_gtfs(gtfs_tidy, tmp_file2) 3.763208 3.803348 3.882299 3.87548 3.910184 4.059277     5
#>    gtfs2gps::write_gtfs(gtfs_2gps, tmp_file3) 2.386184 2.435723 2.536897 2.44019 2.541006 2.881380     5

It may be useful to implement a function such as set_times_to_seconds(), similar to tidytransit::set_hms_times(), in the future. Right now every function that requires time calculation (set_trip_speed(), get_trip_duration()) needs to convert times to seconds inside it. If a function of this sort exists then we just need to check for the existence of time as seconds columns and use it, if it exists. That'll probably save some time in big GTFS files.