reload_rmarkdown_cache function

Reload 'Rmarkdown' cache

Reload 'Rmarkdown' cache in the order files were created, into an R environment

reload_rmarkdown_cache(
  dir = ".",
  maxnum = 1000,
  max_cache_name = NULL,
  envir = new.env(),
  file_sort = c("globals", "objects", "ctime", "mtime"),
  preferred_load_types = c("lazyLoad", "load"),
  dryrun = FALSE,
  verbose = TRUE,
  ...
)

Arguments

• dir: character path to the directory that contains 'Rmarkdown' cache files. Each file is recognized by the file extension ".rdx".

• maxnum: integer indicating the maximum number of cache files to re-load, in order.

• max_cache_name: character optional string indicating the name of an 'Rmarkdown' cache chunk where this function will stop loading cache data. All cache files after this point will not be loaded. This option is intended to help recreate the data available to a particular 'Rmarkdown' chunk during processing.

• envir: environment in which data is populated, default new.env()

  creates a new environment which is returned invisibly.

• file_sort: character string indicating how to sort cache files, default uses best available, in order: "globals" (global index file), "objects" (object index file), "ctime" (creation time), "mtime" (modification time). The global index is preferred, and other options are intended for rare scenarios when the global index is not available. The methods using "mtime" or "ctime"

  is less accurate , yet may be sufficient for simple output.

  • "globals" uses the "__globals" file in the cache directory.
  • "objects" uses the "__objects" file in the cache directory.
  • ctime sorts by file creation time
  • mtime sorts by file modification time

• preferred_load_types: character string indicating the preferred load mechanism, default uses "lazyLoad" if '.rdx'/'.rdb' files are available, otherwise "load" to load '.RData'/'.rda' files. The 'lazyLoad' '.rdx'/.'rdb' files are created when 'Rmarkdown' options include cache=TRUE, cache.lazy=TRUE. The load option is used when cache=TRUE, cache.lazy=FALSE which is preferred for some analyses involving large data objects.

• dryrun: logical default FALSE, whether to perform a dry-run, which prints messages and does not load the data.

• verbose: logical default TRUE, whether to print verbose output. This argument is not passed to other functions.

• ...: additional arguments are passed to lazyLoad() or load()

  as relevant to the method used to re-load the cache object data.

Returns

envir is returned invisibly, with data objects populated into that environment.

Details

This function is intended to help re-load 'Rmarkdown' cache files created during the processing/rendering of an 'Rmarkdown' file.

By default, all cached R objects are loaded into the environment defined by envir, However, it is recommended that ‘envir’ is used to define a new environment

into which the cached session is loaded.

cache_env <- new.env()
reload_rmarkdown_cache(cachedir, envir=cache_env)

From then on, the cached data objects can be seen with ls(cache_env)

and retrieved with get("objectname", envir=cache_env).

If supplied with maxnum or max_cache_name then the cache will be loaded only up to this point, and not beyond. The recommended method to determine the cache is to use dryrun=TRUE

to view all sections, then to choose the integer number, or character name to define the maximum chunk to load.

See Also

Other jam practical functions: breakDensity(), call_fn_ellipsis(), checkLightMode(), check_pkg_installed(), colNum2excelName(), color_dither(), exp2signed(), getAxisLabel(), isFALSEV(), isTRUEV(), jargs(), kable_coloring(), lldf(), log2signed(), middle(), minorLogTicks(), newestFile(), printDebug(), renameColumn(), rmInfinite(), rmNA(), rmNAs(), rmNULL(), setPrompt()