Update historical data in cache

[wilsonfreitas]

Create an engine to update historical data in cache.

Maybe the binary data, already processed inside a data.frame, could be saved in a SQLite database like a BLOB.

Considering that all data downloaded is indexed to a reference date, one alternative is: update the cache with all missing reference dates.

Example:

update_cache(template)
#> Updating <template> cache with <n> dates

When the cache is empty

update_cache(template)
#> x Error no cache for template <template>

check_cache(template)
#> cache for <template> is up to date