Delete saved results from the cache folder

Deletes the saved results chosen by namespace, with their checksum files, any temporary files left by an interrupted write, and the GeoPackage files written by cacs_acs_prefetch(write_gpkg = TRUE), from the cache folder returned by cacs_cache_dir(). Other files in the folder and the subfolders themselves are kept. A folder given in the cache_dir argument of another function is not changed; to clear such a folder, first set the option to it, as in options(catchmentACS.cache_dir = "path/to/folder").

Usage

cacs_clear_cache(
  namespace = c("all", "isochrone", "acs", "acs_test", "intersect"),
  confirm = interactive()
)

Arguments

namespace

A string naming the kind of saved result to delete, which is also the name of its subfolder:

"all" (the default)

All four kinds.

"isochrone"

Drive-time areas saved by cacs_isochrone().

"acs"

American Community Survey (ACS) data saved by cacs_acs_prefetch().

"acs_test"

ACS data saved in test mode (see namespace_mode in cacs_get_cache_state()).

"intersect"

Results saved by cacs_intersect_weight().

confirm

A logical value. If TRUE, a question is asked first, and files are deleted only if the answer is yes; in a non-interactive session nobody can answer, so nothing is deleted. If FALSE, files are deleted without a question. The default, interactive(), is TRUE only in an interactive session, so a script run with Rscript deletes without asking. The question is also skipped when the environment variable CACS_NO_CONFIRM is "1".

Value

A tibble, returned invisibly, with one row for each subfolder cleared and the columns namespace, n_removed (the number of files deleted, counting a saved result, its checksum file, and its GeoPackage file as separate files), and bytes_freed (their total size in bytes). It has no rows when the cache folder does not exist or the answer to the question is no.

Details

After deleting, cacs_clear_cache() sets the hit and miss counts of the cleared subfolders to zero (see cacs_get_cache_state()). If the cache folder does not exist, a message says so and nothing is deleted.

See also

Other cache and configuration: cacs_cache_dir(), cacs_cache_status(), cacs_get_cache_state(), cacs_set_cache()

Examples

# Use a temporary cache folder, so that a cache folder you have set is
# left alone
old <- options(catchmentACS.cache_dir = file.path(tempdir(), "cacs-example"))
cacs_cache_status()
#> # A tibble: 4 × 9
#>   namespace n_entries orphan_tmp n_fingerprints orphan_fingerprint_tmp
#>   <chr>         <int>      <int>          <int>                  <int>
#> 1 isochrone         0          0              0                      0
#> 2 acs               0          0              0                      0
#> 3 acs_test          0          0              0                      0
#> 4 intersect         0          0              0                      0
#> # ℹ 4 more variables: legacy_entries <int>, total_size_mb <dbl>, oldest <dttm>,
#> #   newest <dttm>
cacs_clear_cache("isochrone", confirm = FALSE)
#> Cache directory does not exist; nothing to clear.
#> ℹ Path: /tmp/RtmpMhGiu5/cacs-example
options(old)