If cacheDir takes up more than maxCacheSize megabytes on disk, files will be removed in order of access time by default. Only files matching extensions are eligible for removal. Files can also be removed in order of change time with sortBy='ctime' or modification time with sortBy='mtime'.

The maxFileAge parameter can also be used to remove files that haven't been modified in a certain number of days. Fractional days are allowed. This removal happens without regard to the size of the cache and is useful for removing out-of-date data.

It is important to understand precisely what these timestamps represent:

  • atime -- File access time: updated whenever a file is opened.

  • ctime -- File change time: updated whenever a file's metadata changes e.g. name, permission, ownership.

  • mtime -- file modification time: updated whenever a file's contents change.

manageCache(
  cacheDir = NULL,
  extensions = c("html", "json", "pdf", "png"),
  maxCacheSize = 100,
  sortBy = "atime",
  maxFileAge = NULL
)

Arguments

cacheDir

Location of cache directory.

extensions

Vector of file extensions eligible for removal.

maxCacheSize

Maximum cache size in megabytes.

sortBy

Timestamp to sort by when sorting files eligible for removal. One of atime|ctime|mtime.

maxFileAge

Maximum age in days of files allowed in the cache.

Value

Invisibly returns the number of files removed.

Examples

library(MazamaCoreUtils) # Create a cache directory and fill it with 1.6 MB of data CACHE_DIR <- tempdir() write.csv(matrix(1,400,500), file=file.path(CACHE_DIR,'m1.csv')) write.csv(matrix(2,400,500), file=file.path(CACHE_DIR,'m2.csv')) write.csv(matrix(3,400,500), file=file.path(CACHE_DIR,'m3.csv')) write.csv(matrix(4,400,500), file=file.path(CACHE_DIR,'m4.csv')) for (file in list.files(CACHE_DIR, full.names=TRUE)) { print(file.info(file)[,c(1,6)]) }
#> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 352 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 294 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 2021-11-19 05:54:18 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 470 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 2021-11-19 05:54:19 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 224 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 226 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 2021-11-19 05:54:15 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 486 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 2021-11-19 05:54:17 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m1.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m1.csv 2021-11-19 05:54:19 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m2.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m2.csv 2021-11-19 05:54:19 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 2021-11-19 05:54:20 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 2021-11-19 05:54:20
# Remove files based on access time until we get under 1 MB manageCache(CACHE_DIR, extensions='csv', maxCacheSize=1, sortBy='atime') for (file in list.files(CACHE_DIR, full.names=TRUE)) { print(file.info(file)[,c(1,6)]) }
#> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 352 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 294 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 2021-11-19 05:54:18 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 470 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 2021-11-19 05:54:19 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 224 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 226 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 2021-11-19 05:54:15 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 486 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 2021-11-19 05:54:17 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 2021-11-19 05:54:20 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 2021-11-19 05:54:20
# Or remove files based on modification time manageCache(CACHE_DIR, extensions='csv', maxCacheSize=1, sortBy='mtime') for (file in list.files(CACHE_DIR, full.names=TRUE)) { print(file.info(file)[,c(1,6)]) }
#> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 352 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/downlit 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 294 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf4cda2533 2021-11-19 05:54:18 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 470 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf5c05eb0 2021-11-19 05:54:19 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 224 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eaf74eeb683 2021-11-19 05:54:13 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 226 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafa0bd31b 2021-11-19 05:54:15 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 486 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/file6eafe5096c4 2021-11-19 05:54:17 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m3.csv 2021-11-19 05:54:20 #> size #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 405687 #> atime #> /var/folders/84/y311lppx4519st7n8_gfkd1w0000gn/T//Rtmp3pqn1t/m4.csv 2021-11-19 05:54:20