#!/usr/bin/perl -w
#
# xmlrpc based munin plugin for monitoring rtorrent's memory usage
# prerequisites:
#  - rtorrent 0.7.5 or newer compiled with --with-xmlrpc-c
# check http://libtorrent.rakshasa.no/wiki/RTorrentXMLRPCGuide for further informations
#
# written by Gabor Hudiczius
# web: http://projects.cyla.homeip.net/rtwi/wiki/rTorrentOMeter
# email: ghudiczius@gmail.com
#
# 0.2.0 - 080619
#  support for scgi_port and scgi_local
#  configurable via munin env variables
#  initial release
#
#
# Parameters:
#
#       config          required
#
#
# Configurable variables
#
#       src             "socket" when using scgi_socket, or anything else when using scgi_port
#       socket          rTorrent's rpc socket (scgi_local)      - using scgi_local      - needed, when "src" is set to "socket"
#       category        Change graph category
#
# Configuration example
#
#       [rtom_all]
#       user username
#       env.src socket
#       env.socket /home/user/torrent/.socket/rpc.socket,/home/user/torrent/.socket/rpc.socket
#       env.category Category
#
#%# family=auto


if ( $ARGV[0] and $ARGV[0] eq "autoconf" ) {
        exit 1;
}

if ( $ARGV[0] and $ARGV[0] eq "config" ) {
        my $category = $ENV{"category"} || "";
        print "graph_title rTorrent memory usage\n";
        print "graph_args --base 1024 --lower-limit 0\n";
        print "graph_vlabel Bytes\n";
        print "graph_category rTorrent ".${category}."\n";
        print "mem.label Memory usage\n";
        print "mem.info Memory osage of rTorrent\n";
        print "mem.type GAUGE\n";
        print "mem.draw LINE2\n";
        exit 0;
}

use IO::Socket;
my @sockets = split /,/, $ENV{"socket"} || "";
my $mem = 0;
my $src         = $ENV{"src"} || "";

my $pattern     = qr/<value><(int|i4|i8|ex\.i8)>(\d+)<\/(int|i4|i8|ex\.i8)><\/value>/;
my $line        = "<?xml version=\"1.0\" encoding=\"utf-8\"?><methodCall><methodName>get_memory_usage</methodName></methodCall>";
my $llen        = length $line;
my $header      = "CONTENT_LENGTH\000${llen}\000SCGI\001\000";
my $hlen        = length $header;
$line           = "${hlen}:${header},${line}";

for $socket (@sockets)
{
        if ( ( defined $src ) && ( $src eq "socket" ) ) {
                socket( SOCK, PF_UNIX, SOCK_STREAM, 0 ) or die;
                connect( SOCK, sockaddr_un( $socket ) ) or die $!;
        }

        print SOCK $line;
        flush SOCK;

        while ( $line = <SOCK> ) {
                if ( $line =~ /$pattern/ ) {
                        $mem = $mem + $2;
                }
        }
        close (SOCK);
}

print "mem.value ${mem}\n";

exit;