R/zzz.R

In chrisvwn/Rnightlights: Satellite Nightlight Data Extraction

.onLoad <- function(libname, pkgname)
{
  #increase download timeout to prevent aborted downloads
  .RnightlightsEnv$oldTimeout <- options("timeout")
  
  options("timeout" = pkgOptions("downloadTimeout"))
  
  #display credits
  credits <- "Rnightlights

When using the data please credit the various agencies:

DMSP data collected by US Air Force Weather Agency
Image and data processing by NOAA's National Geophysical Data Center
(https://eogdata.mines.edu/dmsp/downloadV4composites.html)
---
VIIRS data produced by
Earth Observation Group, Payne Institute for Public Policy
(https://eogdata.mines.edu/download_dnb_composites.html)

Maps produced and distributed by GADM
The data are freely available for academic use and other non-commercial use.
Redistribution, or commercial use, is not allowed without prior permission.
Using the data to create maps for academic publishing is allowed.
(https://gadm.org)"
  
  printCredits(credits)
}

######################## .RnightlightsENV ###################################

#' A package-wide hidden environment
#' 
#' A package-wide hidden environment used to store variables/settings and
#'     functions to retrieve them
#' 
.RnightlightsEnv <- new.env(parent = emptyenv())


######################## .onAttach ###################################

.onAttach <- function(libname, pkgname)
{
  # Set global variables in .onAttach since we want the package to be
  #     usable without active loading via library(Rnightlights)
  #
  
  #Setup the data path, possibly by prompting the user. if not found
  if(is.null(getNlDataPath()))
  {
    message(Sys.time(), ": dataPath is not set. Running setupDataPath")
    setupDataPath()
  }
  
  #if path is set but it is not found create it
  if(!dir.exists(dataPath <- getNlDataPath()))
  {
    message(Sys.time(), ": ", dataPath, " does not exist. Creating")
    setNlDataPath(dataPath)
  }
  
  #Create any missing data dirs
  #Upgrade also checks for this so this may make the upgrade one redundant
  createNlDataDirs()
  
  #try to speed up the code
  #does this work?
  #also enabled in DESCRIPTION file
  compiler::enableJIT(3)
  
  upgradeRnightlights()
  
  #load saved stats into memory
  readSavedNlStats()
}

.onUnload <- function(libpath)
{

}

.onDetach <- function(libpath)
{
  #restore the previous timeout option
  options("timeout" = .RnightlightsEnv$oldTimeout)
  
  #remove our hidden environment
  suppressWarnings(rm(.RnightlightsEnv))
}

######################## .Last.lib ###################################

#' @export
.Last.lib <- function(libpath)
{
  # Clean up the environment and delete temp files when the package is
  #     detached.
  #    
  #     Use .Last.lib rather than .onDetach or .onUnload which may not be run
  #     at the end of the session. And rather than reg.finalizer which is
  #     called when gc() runs which we do not want to happen for nlCleanup()
  #     especially since we do call gc() in some instances.

  #cleanup by removing any global vars created etc
  nlCleanup()
  
  compiler::enableJIT(0)
}