#!/bin/bash

## linux-helper: Helper for the multicore and SSH cluster functions of the BatchJobs R
##   package.
##
## Requires the following Unix command line utilities:
##
##  * grep, wc, ps, kill, uptime, echo, cat, possibly setsid
##
## The following commands are implemented. First argument is always the command name.
## For other arguments see below. Each command returns a character vector.
##
## number-of-cpus
##  Return the number of PEs on worker.
##
## start-job NICE JOBFILE OUTFILE
##   Start an Rscript process running doJobCollection on $JOBFILE and log
##   the output in $OUTFILE.
##   Returns: PID of sh process which spawned R. We use that as batch.id.
##
## kill-job PID
##   Kill the R job with PID $PID. The PID is the PID of
##   the sh process returned by start-job.
##   First a TERM is sent, then 1 sec delay, then KILL.
##
##  status FILEDIR
##   Return 4 numbers:
##    - load average of last 1 min, as given by e.g. uptime
##    - number of R processes by _all_ users
##    - number of R processes by _all_ users which have a load of >= 50%
##    - number of R processes by current user
##      which match $FILEDIR/jobs in the cmd call of R
##
##  list-jobs FILEDIR
##   Return the PIDs of running R jobs operating on $FILEDIR/jobs.

echo "[bt] --BOF--"

CMD="$1"; shift
export LC_ALL=C ### Avoid any localization issues.
shopt -s nocasematch ### Case insensitive regular expressions

case $CMD in
    number-of-cpus)
        if [[ `uname` =~ "Linux" ]]; then
          NCPU=`cat /proc/cpuinfo | grep '^processor' | wc -l`
        else ## darwin
          NCPU=`sysctl -n hw.ncpu`
        fi
        echo "[bt]" $NCPU
        ;;
    start-job)
        Rscript -e "batchtools::doJobCollection('$1')" > "$2" 2>&1 &
        echo "[bt]" $!
        ;;
    kill-job)
        kill -TERM $1 > /dev/null 2> /dev/null
        sleep 1
        kill -KILL $1 > /dev/null 2> /dev/null
        exit 0
        ;;
    status)
        # remove everyting till load average(s), then delete commas
        LOAD=$(uptime | awk '{gsub(/.*:/,""); {gsub(/,/,"")}; print $1}')
        JOBDIR="$1/jobs"
        # print 3 columns for all processes
        # use ww for unlimited width in ps for command output
        # we count all R procs, all R50, and all where JOBDIR was in the call args
        ps -e -ww -o pcpu= -o ucomm= -o command= | \
        awk -v j=$JOBDIR -v sysload=$LOAD '
          BEGIN {rprocs=0;rprocs_50=0;njobs=0}
          $2 != "R" {next}
          {rprocs++}
          $1 > 50.0 {rprocs_50++}
          $0 ~ j {njobs++}
          END {print "[bt] " sysload " " rprocs " " rprocs_50 " " njobs}'
        ;;
    list-jobs)
        JOBDIR="$1/jobs"
        ps -e -ww -o pid= -o ucomm= -o command= | awk -v j=$JOBDIR '$2 == "R" && $0 ~ j { print "[bt] " $1 }'
        ;;
    *)
esac

echo "[bt] --EOF--"
