Package 'runonce'

Title: Run Once and Save Result
Description: Package 'runonce' helps automating the saving of long-running code to help running the same code multiple times. If you run some long-running code once, it saves the result in a file on disk. Then, if the result already exists, i.e. if the code has already been run and its output has already been saved, it just reads the result from the stored file instead of running the code again.
Authors: Florian Privé [aut, cre]
Maintainer: Florian Privé <[email protected]>
License: GPL-3
Version: 0.2.3
Built: 2024-11-21 04:34:59 UTC
Source: https://github.com/privefl/runonce

Help Index

Download once

Description

Download file if does not exist yet.

Usage

download_file(
  url,
  dir = tempdir(),
  fname = url_basename(url),
  overwrite = FALSE,
  mode = "wb",
  ...
)

Arguments

url

URL of file to be downloaded.
dir

Directory where to download the file.
fname

Base name of the downloaded file (dir will be prefixed).
overwrite

Whether to overwrite? Default is FALSE.
mode

See parameter of download.file(). Default of "wb" seems useful for Windows systems.
...

Arguments passed on to utils::download.file

method

Method to be used for downloading files. Current download methods are "internal", "wininet" (Windows only) "libcurl", "wget" and "curl", and there is a value "auto": see ‘Details’ and ‘Note’.

The method can also be set through the option "download.file.method": see options().

quiet

If TRUE, suppress status messages (if any), and the progress bar.

cacheOK

logical. Is a server-side cached value acceptable?

extra

character vector of additional command-line arguments for the "wget" and "curl" methods.

headers

named character vector of HTTP headers to use in HTTP requests. It is ignored for non-HTTP URLs. The User-Agent header, coming from the HTTPUserAgent option (see options) is used as the first header, automatically.

Value

Path to the downloaded (or existing) file.

Examples

download_file("https://github.com/privefl.png")
download_file("https://github.com/privefl.png")
download_file("https://github.com/privefl.png", overwrite = TRUE)

Cache result

Description

Cache the result of code in an RDS file.

Usage

save_run(code, file, timing = TRUE)

Arguments

code

Code to run. Do not forget to wrap it with { }. Also, beware that it is your job to make sure your code and data has not changed. If this is the case, you need to remove the file storing the outdated result.
file

File path where the result is stored. Should have extension rds.
timing

Whether to print timing of running code? Default is TRUE.

Value

The evaluation of code the first time, the content of file otherwise.

Examples

# Prepare some temporary file
tmp <- tempfile(fileext = ".rds")

# Run once because result does not exist yet
save_run({
  Sys.sleep(2)
  1
}, file = tmp)

# Skip run because the result already exists
# (but still output how long it took the first time)
save_run({
  Sys.sleep(2)
  1
}, file = tmp)

Skip code

Description

Skip code if all conditions are fulfilled. The code should not return anything.

Usage

skip_run_if(code, cond = NULL, files = NULL, timing = TRUE)

Arguments

code

Code to run. Do not forget to wrap it with { }.
cond

Condition to be fulfilled to skip running code. Default is NULL (not used). Should evaluate to either TRUE or FALSE otherwise.
files

Character vector of file path(s). Default is NULL (not used). This function checks if all these files exist, and if they all do exist, it skips running code.
timing

Whether to print timing of running code? Default is TRUE.

Value

NULL, invisibly.

Examples

# Prepare some temporary file
tmp <- tempfile(fileext = ".txt")

# Run once because file does not exist yet
skip_run_if({
  Sys.sleep(2)
  write.table(iris, tmp)
}, cond = file.exists(tmp))

# Skip run because `cond` is `TRUE`
skip_run_if({
  Sys.sleep(2)
  write.table(iris, tmp)
}, cond = file.exists(tmp))

# Skip run because file exists
skip_run_if({
  Sys.sleep(2)
  write.table(iris, tmp)
}, files = tmp)