R/buildCluster.R

In bogdanoancea/inference: R package for computing the number of individuals in the target population conditioned on the number of individuals detected by the MNO and auxiliary information.

#' @title Builds a cluster of working nodes.
#'
#' @description Builds a cluster of working nodes using the \code{parallel}
#'   package. On Unix-like operating systems it builds as "FORK" cluster while
#'   on Windows it builds a "SOCKET" cluster. The number of working nodes equals
#'   the number of available (logical) cores as it is detected by the call of
#'   \code{detectCores()} function. On Windows, it also exports a list of
#'   variables and an environment passed as arguments. This is an internal
#'   function of the package, and it is not available to be direclty called by
#'   users.
#'
#' @param varlist A list of variables to be exported to every working node.
#'
#' @param env An environment to be exported to every working node.
#'
#' @return A cluster object used to distribute the computations.
#' @keywords internal
#' @import data.table
#' @import deduplication
#' @import parallel
#' @import doParallel
buildCluster <- function(varlist, env) {

    if (Sys.info()[['sysname']] == 'Linux' |
        Sys.info()[['sysname']] == 'Darwin') {
        cl <- makeCluster(detectCores(), type = "FORK")
    } else {
        cl <- makeCluster(detectCores())
        clusterEvalQ(cl, library("data.table"))
        clusterEvalQ(cl, library("deduplication"))
        clusterExport(cl, varlist, envir = env)
    }
    return (cl)
}