Empties the memoised in-session cache and, optionally, the on-disk one.
Arguments
- source
Which source's cache to clear, or
NULL(default) for all. The built-in sources persist to disk, one directory each under the cache (wdi,wdi-archivefor pinned World Bank releases,owid,oecd,imf,ilo,eurostat,comtrade); a source you registered yourself is memoised for the session only.- disk
Also delete that source's on-disk entries (default
FALSE). Only the cache's own files are removed, and a directory only when that leaves it empty.
What a global clear releases
Called with no source, this also drops the two cached geometry backends:
the Natural Earth sf layer held per scale (tens of megabytes at
scale = "medium") and the polygon backend's memoised vertex table (about
98,000 rows per override set). Those are the largest things the package
keeps in memory, and in a long-lived process – a Shiny app or a plumber
API – this is the only way to release them. They rebuild on the next map.
Naming a source leaves geometry alone, since it is not a data source.
Where the cache lives
The persistent cache goes in the standard per-user cache location,
tools::R_user_dir("countryatlas", "cache"). Point it elsewhere with
options(countryatlas.cache_dir = ), or skip it by passing cache = FALSE
to world_data() or country_data(). Under R CMD check the whole cache
moves to the session temp directory, so a check never writes to the user's
file space.
Entries expire: a fetch from a current release is dropped once it is 30
days old, because providers revise their figures, and past 50 MB per
source the least-recently-used entries go first. Adjust either with
options(countryatlas.cache_max_age = ) (seconds) and
options(countryatlas.cache_max_size = ) (bytes). A pinned World Bank
release (wdi_vintages()) never changes, so its entries never expire.