manageCache: Manage the Size of a Cache

In MazamaScience/MazamaWebUtils: Utility Functions for Building Web Databrowsers

Description

If cacheDir takes up more than maxCacheSize megabytes on disk, files wll be removed in order of oldest access time. Only files matching extensions are eligible for removal.

Usage

manageCache(cacheDir, extensions = c("html", "json", "pdf", "png"),
  maxCacheSize = 100)

Arguments

cacheDir	location of cache directory
extensions	vector of file extensions eligible for removal
maxCacheSize	maximum cache size in megabytes

Value

Invisibly returns the number of files removed.

Examples

# 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)])
}
# Remove files based on last access time until we get under 1 MB
manageCache(CACHE_DIR, extensions='csv', maxCacheSize=1)
for (file in list.files(CACHE_DIR, full.names=TRUE)) {
  print(file.info(file)[,c(1,6)])
}

MazamaScience/MazamaWebUtils documentation built on May 29, 2019, 2:09 p.m.