Package 'hoardr'

hoardr

Description

Manage Cached Files

Details

hoardr is a tiny package with just a single export hoard(). The package goal is to make it easy to setup, use, and manage cached files for another R package. In addition, you can export functions in your own package using hoardr for users to manage their cached files.

Author(s)

Scott Chamberlain [email protected]

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hoardr class

Description

hoardr class

Arguments

path	(character) a path to cache files in. required
type	(character) type of cache. One of "user_cache_dir" (default), "user_log_dir", "user_data_dir", "user_config_dir", "site_data_dir", "site_config_dir". Can also pass in any function that gives a path to a directory, e.g., tempdir(). required.

Details

For the purposes of caching, you'll likely want to stick with user_cache_dir, but you can change the type of cache with the type parameter.

hoard is just a tiny wrapper around HoardClient$new(), which isn't itself exported, but you can use it if you want via :::

Methods

cache_path_get()

Get the cache path return: (character) path to the cache directory

cache_path_set(path = NULL, type = "user_cache_dir", prefix = "R", full_path = NULL)

Set the cache path. By default, we set cache path to file.path(user_cache_dir, prefix, path). Note that this does not actually make the directory, but just sets the path to it.

• path (character) the path to be appended to the cache path set by type

• type (character) the type of cache, see rappdirs

• prefix (character) prefix to the path value. Default: "R"

• full_path (character) instead of using path, type, and prefix just set the full path with this parameter

return: (character) path to the cache directory just set

list()

List files in the directory (full file paths) return: (character) vector of file paths for files in the cache

mkdir()

Make the directory if doesn't exist already return: TRUE, invisibly

delete(files, force = TRUE)

Delete files by name

• files (character) vector/list of file paths

• force (logical) force deletion? Default: TRUE

return: nothing

delete_all(force = TRUE)

Delete all files

• force (logical) force deletion? Default: FALSE

return: nothing

details(files = NULL)

Get file details

• files (character) vector/list of file paths

return: objects of class cache_info, each with brief summary info including file path and file size

keys(algo = "md5")

Get a hash for all files. Note that these keys may not be unique if the files are identical, leading to identical hashes return: (character) hashes for the files

key(x, algo = "md5")

Get a hash for a single file. Note that these keys may not be unique if the files are identical, leading to identical hashes

• x (character) path to a file

• algo (character) the algorithm to be used, passed on to digest::digest(), choices: md5 (default), sha1, crc32, sha256, sha512, xxhash32, xxhash64 and murmur32.

return: (character) hash for the file

files()

Get all files as HoardFile objects return: (character) paths to the files

compress()

Compress files into a zip file - leaving only the zip file return: (character) path to the cache directory

uncompress()

Uncompress all files and remove zip file return: (character) path to the cache directory

exists(files)

Check if files exist

• files: (character) one or more files, paths are optional

return: (data.frame) with two columns:

• files: (character) file path

• exists: (boolean) does it exist or not

Examples

(x <- hoard())
x$cache_path_set(path = "foobar", type = 'tempdir')
x
x$path
x$cache_path_get()

# Or you can set the full path directly with `full_path`
mydir <- file.path(tempdir(), "foobar")
x$cache_path_set(full_path = mydir)
x
x$path
x$cache_path_get()

# make the directory if doesn't exist already
x$mkdir()

# list files in dir
x$list()
cat(1:10000L, file = file.path(x$cache_path_get(), "foo.txt"))
x$list()

# add more files
cat(letters, file = file.path(x$cache_path_get(), "foo2.txt"))
cat(LETTERS, file = file.path(x$cache_path_get(), "foo3.txt"))

# see if files exist
x$exists("foo.txt") # exists
x$exists(c("foo.txt", "foo3.txt")) # both exist
x$exists(c("foo.txt", "foo3.txt", "stuff.txt")) # one doesn't exist

# cache details
x$details()

# delete files by name - we prepend the base path for you
x$delete("foo.txt")
x$list()
x$details()

# delete all files
cat("one\ntwo\nthree", file = file.path(x$cache_path_get(), "foo.txt"))
cat("asdfasdf asd fasdf", file = file.path(x$cache_path_get(), "bar.txt"))
x$delete_all()
x$list()

# make/get a key for a file
cat(1:10000L, file = file.path(x$cache_path_get(), "foo.txt"))
x$keys()
x$key(x$list()[1])

# as files
Map(function(z) z$exists(), x$files())

# compress and uncompress
x$compress()
x$uncompress()

# reset cache path
x$cache_path_set(path = "stuffthings", type = "tempdir")
x
x$cache_path_get()
x$list()

# cleanup
unlink(x$cache_path_get())

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