#!/bin/sh
# -*- sh -*-

# shellcheck disable=SC2046

: << =cut

=head1 NAME

memory - Plugin to measure memory on osx.

=head1 NOTES

This plugin runs the top command once per interval, to discover memory usage on OSX.
Contributions are welcome to collect additional memory regions, if possible, such as buffers and caches.

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut

if [ "$1" = "autoconf" ]; then
    if [ "$(uname)" = "Darwin" ]; then
        echo yes
        exit 0
    else
        echo "no (uname does not report 'Darwin')"
        exit 0
    fi
fi

TOTALMEM=$(sysctl hw.memsize | cut -d" " -f2)
graphlimit=$TOTALMEM

dehumanise() {
    echo "$1" | sed -e "s/K/*1024/g;s/M/*1024*1024/;s/G/*1024*1024*1024/;s/T/*1024*1024*1024*1024/"
}

if [ "$1" = "config" ]; then
        echo 'graph_title Memory'
        echo "graph_order used wired unused"
        echo "graph_args --base 1024 -r --lower-limit 0 --upper-limit $graphlimit"
        echo 'graph_vlabel Bytes'
        echo 'graph_category system'
        echo 'used.label used (not incl. wired)'
        echo 'used.draw AREA'
        echo 'used.min 0'
        echo "used.info Used memory, not including wired"
        echo 'wired.label wired'
        echo 'wired.draw STACK'
        echo 'wired.min 0'
        echo 'wired.info Wired memory'

        exit 0
fi

TOPINFO=$(top -l 1 | grep "PhysMem: ")
MEM_USED=$(echo "$TOPINFO" | awk '/PhysMem: / { print substr($2, 1, length($2)) }')
MEM_WIRED=$(echo "$TOPINFO" | awk '/PhysMem: / { print substr($4, 2, length($4)-1) }') 
echo "used.value" $(( $(dehumanise "$MEM_USED") - $(dehumanise "$MEM_WIRED") ))
echo "wired.value" $(( $(dehumanise "$MEM_WIRED") ))