degauss_run cannot use cache or downloaded files

[cole-brokamp]

• show an example of using https://memoise.r-lib.org/ to speed up repeat calculations
• write a vignette on its integration with {targets}?
• option to use a docker daemon on a remote host?

[erikarasnick]

degauss_run works well with {targets} but only caches the target objects and re-runs any function that depends on a target that changed upstream... so doesn't help with the s3_downloads folder problem (e.g., address file -> geocoded -> narr pipeline, if one address changes, the entire pipeline would re-run and narr s3 chunks would not be cached due to temp folder associated with degauss_run)

[cole-brokamp]

Based on our discussion today, it sounds like the best path forward will be to not spend time/energy on fixing this now with {targets} or anything more advanced.

Instead, add an example in the vignette that shows how to use https://memoise.r-lib.org/ to speed up repeat calculations. Something like:

fc <- memoise::cache_filesystem(fs::path(fs::path_wd(), "data-raw"))
degauss_run <- memoise::memoise(degauss_run, omit_args = c("quiet"), cache = fc)

Make sure to add a note explaining how/why caching is not expected to work normally with DeGAUSS when using DeGAUSS from R with dht::degauss_run

[cole-brokamp]

• Use https://github.com/geomarker-io/s3#customizing-download-location to set path to "downloads cache" as a folder in the current working directory (fs::path_abs("s3_downloads")).
• Also mount this directory when running DeGAUSS containers and set options in R in container to use the directory for s3_downloads

[cole-brokamp]

In container,

options(s3.download_folder = "/s3_downloads")

and on call to container, find working directory and bind mount to /s3_downloads

glue::glue("-v {getwd()}:/s3_downloads}") 

[cole-brokamp]

create intermediate csv files, caches, and run docker from tools::R_user_dir("dht", "cache") instead of tempfile()