topserver: topserver

# get_topserver.R

#' Query Paul's topserver page
#' @return A data frame
#' @examples
#'> get_topserver()
#'   hostnames Idle.time CPUs  days  load numerator denominator mystery
#'1     anaona     53.50   40 60.64 40.14        41         385   39740
#'2     anbona     26.28   40 60.64 49.97        51         430    7054
#'3     ancona     75.20   40 60.64 39.14        40         387   35428
#'4     andona     40.94   40 60.64 38.05        39         367   33184
#'5     bivona     87.84   32 60.64 31.09        32         318    3135
#'6     briona     95.32   24 60.64  8.05         9         256    7208
#'7     cetona     99.15    8 29.04  0.05         1         130   26051
#'8     esaona     32.62   32 60.64 32.11        33         326   21900
#'9     esbona     74.67   32 60.64 32.06        33         331   28555
#'10    escona     73.85   32 60.64 32.08        34         327   26460
#'11    esdona     47.07   32 60.64 32.10        33         324    8797
#'12    gemona    100.00   24 60.64  0.05         1         230    8494
#'13    oraona     81.44   32 60.64 33.07        34         328   13174
#'14    orbona     78.62   32 60.64 33.08        34         340    5594
#'15    orcona     80.96   32 60.64 33.08        34         327   16024
#'16    ordona     82.29   32 60.64 33.08        34         328   22895
#'17    ossona     99.66    8 60.64  0.05         1         127    4115
#'18    parona     99.85    8 60.64  0.05         1         127    4107
#'19    savona     44.01   32 60.64 34.97        25        1231   17344
#'20    verona     61.41   48 60.65 21.93        22         652   29479
#' @export
get_topserver <- function()
{
	http_response <- RCurl::getURL("http://www.maths.usyd.edu.au/ub/psz/loc/topserver")

	html_lines <- str_split(http_response, "\\n")[[1]]
	html_lines <- html_lines[11:30]
	dehtml_lines <- map_chr(html_lines, function (s) str_replace(s, "<a href='#.*'>(.*)</a>: ", "\\1: "))

	# Sample line: "anaona: Idle time 53.54% on 40 CPUs over  60.59 days; load 40.13 41/385 38604"
	# The pattern is:
	# host: Idle time dd.dd% on dd CPUs over *dd.dd days; load dd.dd dd/ddd ddddd
	pattern <- "(.*):.*Idle time(.*)% on (.*) CPUs over * (.*) days; load (.*) (.*)/(.*) (.*)"
	matches <- map(dehtml_lines, function(s) str_match(s, pattern))

	# matches is a list. Convert it to a matrix.
	hostnames <- vector("character", length(matches))
	mat <- matrix(0, nrow=length(matches), ncol=7)
	for (i in 1:length(matches)) {
		hostnames[i] <- matches[[i]][2]
		for (j in 1:7) {
			mat[i, j] <- as.numeric(matches[[i]][2 + j])
		}
	}
	colnames(mat) <- c("Idle time", "CPUs", "days", "load", "numerator", "denominator", "mystery")
	df <- data.frame(mat)
	df$hostnames <- hostnames
	df <- df[c(8, 1:7)]

	return(df)
}