#!/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 information
#
# 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"
#       ip              rTorrent's ip address                   - using scgi_port       - needed, when "src" is NOT set to "socket"
#       port            rTorrent's scgi port (scgi_port)        - using scgi_port       - needed, when "src" is NOT set to "socket"
#       category        Change graph category
#       api             use "pre09" (pre 0.9.0) or "current" (0.9.0+, the default) API calls
#
# Configuration example
#
#       [rtom_allsessions_*]
#       user username
#       env.src socket
#       env.socket /home/user/torrent/.socket/rpc.socket,/home/user/torrent/.socket/rpc.socket
#       env.category Category
#       env.api current
#
#       [rtom_allsessions_*]
#       user username
#       env.port 5000,5001,5002,5003
#       env.category Category
#
#%# family=auto


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

use IO::Socket;
my $src         = $ENV{"src"} || "";
my @sockets     = split /,/, $ENV{"socket"} || "";
my $ip          = $ENV{"ip"} || "127.0.0.1";
my @ports       = split /,/, $ENV{"port"} || "";
my $api         = $ENV{"api"} || "current";

my $mem         = 0;
my $pattern     = qr/<value><(int|i4|i8|ex\.i8)>(\d+)<\/(int|i4|i8|ex\.i8)><\/value>/;
my $line        = "";
if ($api =~ /pre09/) {
  $line         = "<?xml version=\"1.0\" encoding=\"utf-8\"?><methodCall><methodName>get_memory_usage</methodName></methodCall>";
} else {
  $line         = "<?xml version=\"1.0\" encoding=\"utf-8\"?><methodCall><methodName>pieces.memory.current</methodName></methodCall>";
}
my $llen        = length $line;
my $header      = "CONTENT_LENGTH\000${llen}\000SCGI\001\000";
my $hlen        = length $header;

if ( ( defined $src ) && ( $src eq "socket" ) ) {
  for $socket (@sockets)
  {
    socket( SOCK, PF_UNIX, SOCK_STREAM, 0 ) or die;
    connect( SOCK, sockaddr_un( $socket ) ) or die $!;
    my $line = "${hlen}:${header},${line}";
    print SOCK $line;
    flush SOCK;
    while ( $line = <SOCK> ) {
      if ( $line =~ /$pattern/ ) {
        $mem = $mem + $2;
      }
    }
    close (SOCK);
  }
} else {
  for $port (@ports)
  {
    socket( SOCK, PF_INET, SOCK_STREAM, getprotobyname( "tcp" ) );
    connect( SOCK, sockaddr_in( $port, inet_aton( $ip ) ) );
    my $line = "${hlen}:${header},${line}";
    print SOCK $line;
    flush SOCK;
    while ( $line = <SOCK> ) {
      if ( $line =~ /$pattern/ ) {
        $mem = $mem + $2;
      }
    }
    close (SOCK);
  }
}

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

exit;
