Cache for CRAN archive data — cran_archive

This is an R6 class that implements a cache from older CRAN package versions. For a higher level interface see the functions documented with cran_archive_list().

Details

The cache is similar to cranlike_metadata_cache and has the following layers:

The data inside the cran_archive_cache object.
Cached data in the current R session.
An RDS file in the current session's temporary directory.
An RDS file in the user's cache directory.

It has a synchronous and an asynchronous API.

Usage

cac <- cran_archive_cache$new(
  primary_path = NULL,
  replica_path = tempfile(),
  cran_mirror = default_cran_mirror(),
  update_after = as.difftime(7, units = "days"),
)

cac$list(packages = NULL, update_after = NULL)
cac$async_list(packages = NULL, update_after = NULL)

cac$update()
cac$async_update()

cac$check_update()
cac$async_check_update()

cac$summary()

cac$cleanup(force = FALSE)

Arguments

primary_path: Path of the primary, user level cache. Defaults to the user level cache directory of the machine.
replica_path: Path of the replica. Defaults to a temporary directory within the session temporary directory.
cran_mirror: CRAN mirror to use, this takes precedence over repos.
update_after: difftime object. Automatically update the cache if it gets older than this. Set it to Inf to avoid updates. Defaults to seven days.
packages: Packages to query, character vector.
force: Whether to force cleanup without asking the user.

Details

Create a new archive cache with cran_archive_cache$new(). Multiple caches are independent, so e.g. if you update one of them, the other existing caches are not affected.

cac$list() lists the versions of the specified packages, or all packages, if none were specified. cac$async_list() is the same, but asynchronous.

cac$update() updates the cache. It always downloads the new metadata. cac$async_update() is the same, but asynchronous.

cac$check_update() updates the cache if there is a newer version available. cac$async_check_update() is the same, but asynchronous.

cac$summary() returns a summary of the archive cache, a list with entries:

cachepath: path to the directory of the main archive cache,
current_rds: the RDS file that stores the cache. (This file might not exist, if the cache is not downloaded yet.)
lockfile: the file used for locking the cache.
`timestamp: time stamp for the last update of the cache.
size: size of the cache file in bytes.

cac$cleanup() cleans up the cache files.

Columns

cac$list() returns a data frame with columns:

package: package name,
version: package version. This is a character vector, and not a package_version() object. Some older package versions are not supported by package_version().
raw: the raw row names from the CRAN metadata.
mtime: mtime column from the CRAN metadata. This is usually pretty close to the release date and time of the package.
url: package download URL.
mirror: CRAN mirror that was used to get this data.

Examples

arch <- cran_archive_cache$new()
arch$update()
#> # A data frame: 144,697 × 6
#>    package  version raw                   mtime               url   mirror
#>  * <chr>    <chr>   <chr>                 <dttm>              <chr> <chr> 
#>  1 A3       0.9.1   A3/A3_0.9.1.tar.gz    2013-02-07 09:00:29 http… https…
#>  2 A3       0.9.2   A3/A3_0.9.2.tar.gz    2013-03-26 18:58:40 http… https…
#>  3 aaMI     1.0-0   aaMI/aaMI_1.0-0.tar.… 2005-06-24 15:55:17 http… https…
#>  4 aaMI     1.0-1   aaMI/aaMI_1.0-1.tar.… 2005-10-17 19:24:18 http… https…
#>  5 aaSEA    1.0.0   aaSEA/aaSEA_1.0.0.ta… 2019-08-01 09:10:08 http… https…
#>  6 aaSEA    1.1.0   aaSEA/aaSEA_1.1.0.ta… 2019-11-09 16:20:04 http… https…
#>  7 AATtools 0.0.1   AATtools/AATtools_0.… 2020-06-14 15:10:07 http… https…
#>  8 aba      0.0.9   aba/aba_0.0.9.tar.gz  2021-12-16 20:50:07 http… https…
#>  9 abbyyR   0.1     abbyyR/abbyyR_0.1.ta… 2015-06-12 04:43:35 http… https…
#> 10 abbyyR   0.2     abbyyR/abbyyR_0.2.ta… 2015-09-12 15:19:59 http… https…
#> # ℹ 144,687 more rows
arch$list()
#> # A data frame: 144,697 × 6
#>    package  version raw                   mtime               url   mirror
#>  * <chr>    <chr>   <chr>                 <dttm>              <chr> <chr> 
#>  1 A3       0.9.1   A3/A3_0.9.1.tar.gz    2013-02-07 09:00:29 http… https…
#>  2 A3       0.9.2   A3/A3_0.9.2.tar.gz    2013-03-26 18:58:40 http… https…
#>  3 aaMI     1.0-0   aaMI/aaMI_1.0-0.tar.… 2005-06-24 15:55:17 http… https…
#>  4 aaMI     1.0-1   aaMI/aaMI_1.0-1.tar.… 2005-10-17 19:24:18 http… https…
#>  5 aaSEA    1.0.0   aaSEA/aaSEA_1.0.0.ta… 2019-08-01 09:10:08 http… https…
#>  6 aaSEA    1.1.0   aaSEA/aaSEA_1.1.0.ta… 2019-11-09 16:20:04 http… https…
#>  7 AATtools 0.0.1   AATtools/AATtools_0.… 2020-06-14 15:10:07 http… https…
#>  8 aba      0.0.9   aba/aba_0.0.9.tar.gz  2021-12-16 20:50:07 http… https…
#>  9 abbyyR   0.1     abbyyR/abbyyR_0.1.ta… 2015-06-12 04:43:35 http… https…
#> 10 abbyyR   0.2     abbyyR/abbyyR_0.2.ta… 2015-09-12 15:19:59 http… https…
#> # ℹ 144,687 more rows