crancache: Transparent Caching of Packages from CRAN-like Repositories

In r-lib/crancache: Transparent Caching of Packages from CRAN-Like Repositories

Transparent Caching of Packages from CRAN-like Repositories

Description

Provides wrappers for utils::install.packages(), utils::download.packages() and utils::update.packages() that transparently cache downloaded packages in a local CRAN-like repository.

Configuration

The package can be configured via environment variables. The reason for this (as opposed to direct argument to the functions), is that crancache functions are often used via other packages (e.g. remotes), and the user does not call them directly. Environment variables still allow an easy configuration, especially with the withr package. See examples below.

Environment variables:

• CRANCACHE_DISABLE: set this to a non-empty value to disable crancache completely.

• CRANCACHE_REPOS: set this to a comma separated list of repository names (e.g. cran or other, see get_cache_package_dirs(). If empty string or unset, all local repositories are used.

• CRANCACHE_DISABLE_UPDATES: set this to a non-empty value to disable updates to the cache.

• CRANCACHE_DISABLE_BINARY_UPDATES: set this to a non-empty value to disable adding just-built binary packages to the cache. (Downloaded binaries are still added.)

• CRANCACHE_QUIET: if set to a non-empty value, then crancache does not print status messages to the screen.

If non of these environment variables are set (i.e. by default) the cache is used and updated and all cache repositories are active.

Examples

## Not run: 
## Install a package with remotes, enable the cache
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA),
  remotes::install_local("my-local-package")
)

## Install a package with remotes, disable the cache
withr::with_envvar(
  c(CRANCACHE_DISABLE = "yes"),
  remotes::install_local("my-local-package")
)

## Install a package with cache, but do not update the cache
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_DISABLE_UPDATES = "yes"),
  remotes::install_local("my-local-package")
)

## Install a package with cache, disable binary updates
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_DISABLE_BINARY_UPDATES = "yes"),
  remotes::install_local("my-local-package")
)

## See which repos are active for various CRANCACHE_REPOS settings
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_REPOS = NA),
  get_crancache_repos()
)
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_REPOS = ""),
  get_crancache_repos()
)
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_REPOS = "cran"),
  get_crancache_repos()
)
withr::with_envvar(
  c(CRANCACHE_DISABLE = NA, CRANCACHE_REPOS = "cran,other"),
  get_crancache_repos()
)

## End(Not run)

r-lib/crancache documentation built on July 27, 2023, 4:55 p.m.