Forked from hadley/memoise

devtools::install_github("danielecook/memoise")

If a function is called multiple times with the same input, you can often speed things up by keeping a cache of known answers that it can retrieve. This is called memoisation http://en.wikipedia.org/wiki/Memoization. This is a fork of the memoise package built by Hadley Wickham: hadley/memoise, which provides a simple syntax

mf <- memoise(f)

to create mf(), a memoised wrapper around f(). You can clear mf's cache with

forget(mf)

, and you can test whether a function is memoised with

is.memoised(mf) # TRUE
is.memoised(f)  # FALSE

memoise extends upon memoise by adding in additional types of caches. Items can be cached using the original cache implemented in memoise in addition to other options:

• Google Datastore
• cache_filesystem allows caching using dropbox/google drive.
• AWS

Use cache_datastore to set up a cache on google datastore. Requires you to set a project and cache_name. The cache_name is used to set the kind for each entity stored on google datastore.

library(xmemoise)

# Generate a memoised function.
mrunif <- memoise(runif, cache = cache_datastore("<project id here>", "rcache"))

mrunif(10) # First run, saves cache
mrunif(10) # Loads cache, results should be identical

Use cache_s3 to cache objects using s3 storage. Requires you to specify a bucket using cache_name. When creating buckets, they must be unique among all s3 users when created.

Sys.setenv("AWS_ACCESS_KEY_ID" = "<access key>",
           "AWS_SECRET_ACCESS_KEY" = "<access secret>")

mrunif <- memoise(runif, cache = cache_s3("<unique bucket name>"))

mrunif(10) # First run, saves cache
mrunif(10) # Loads cache, results should be identical

cache_filesystem can be used to cache between computers using Google Drive or Dropbox.

dbc <- cache_filesystem("~/Dropbox/.rcache")
mrunif <- memoise(runif, cache = dbc)
mrunif(20) # Results stored in Dropbox .rcache folder will be synced between computers.

gdc <- cache_filesystem("~/Google Drive/.rcache")
mrunif <- memoise(runif, cache = dbc)
mrunif(20) # Results stored in Google Drive .rcache folder will be synced between computers.