fujiwara · January 28, 2011 08:57
diff --git a/gistfile1.pl b/gistfile1.pl
 #!/usr/bin/env perl
 use strict;
 use warnings;

 use Plack::Builder;
 use AnyEvent;
 use Cache::LRU;
 use Sys::Virt;
 use JSON;
 use Data::Section::Simple qw/ get_data_section /;

 sub watch {
    my $cb = shift;
    my $cache  = Cache::LRU->new( size => 60 );
    my $timer  = AnyEvent->timer(
        interval => 1,
        cb       => sub {
            $cache->set( time() => $cb->() );
        },
    );

    sub {
        $timer; # hold in closure
        my $now = time;
        return [
            map {
                [ $_ => $cache->get($now + $_) ]
            } (-59 .. 0)
        ];
    };
 }

 my $feeder = do {
    my $virt = Sys::Virt->new( uri => "qemu:///system" );
    my $prev_value;
    sub {
        my $dom = $virt->get_domain_by_name("foo");
        my ($vcpu) = $dom->get_vcpu_info();
        my $usage;
        if ($prev_value) {
            $usage = ($vcpu->{cpuTime} - $prev_value) / (1000 ** 3) * 100;
        }
        $prev_value = $vcpu->{cpuTime};
        return $usage;
    };
 };
 my $retriever = watch $feeder;

 builder {
    enable "Plack::Middleware::Static",
        path => qr{^/static/}, root => ".";
    mount "/" => sub {
        [ 200,
          [ "Content-Type" => "text/html" ],
          [ get_data_section("html") ],
        ];
    };
    mount "/usage" => sub {
        [ 200,
          [ "Content-Type" => "application/json" ],
          [ encode_json $retriever->() ],
        ];
    };
 };

 __DATA__

 @@ html
 <!doctype html>
 <html>
  <head>
    <link rel="stylesheet" type="text/css" href="static/jquery.jqplot.css" />
    <script type="text/javascript" src="static/jquery-1.4.1.min.js"></script>
    <script type="text/javascript" src="static/jquery.jqplot.min.js"></script>
    <script type="text/javascript">
      function plot() {
        $.getJSON("/usage", function(data) {
          $("#chartdiv").html("");
          $.jqplot('chartdiv',
            [ data ],
            { title:'CPU Uasge(%)',
              axes:{ yaxis:{ min:0, max:100 }, xaxis:{ min:-60, max:0 } },
            }
          );
        });
      }
      $(document).ready(function(){
        setInterval(plot, 1000)
      });
    </script>
  </head>
  <body>
    <div id="chartdiv" style="height:400px;width:600px;"></div>
  </body>
 </html>
	#!/usr/bin/env perl
	use strict;
	use warnings;

	use Plack::Builder;
	use AnyEvent;
	use Cache::LRU;
	use Sys::Virt;
	use JSON;
	use Data::Section::Simple qw/ get_data_section /;

	sub watch {
	my $cb = shift;
	my $cache = Cache::LRU->new( size => 60 );
	my $timer = AnyEvent->timer(
	interval => 1,
	cb => sub {
	$cache->set( time() => $cb->() );
	},
	);

	sub {
	$timer; # hold in closure
	my $now = time;
	return [
	map {
	[ $_ => $cache->get($now + $_) ]
	} (-59 .. 0)
	];
	};
	}

	my $feeder = do {
	my $virt = Sys::Virt->new( uri => "qemu:///system" );
	my $prev_value;
	sub {
	my $dom = $virt->get_domain_by_name("foo");
	my ($vcpu) = $dom->get_vcpu_info();
	my $usage;
	if ($prev_value) {
	$usage = ($vcpu->{cpuTime} - $prev_value) / (1000 ** 3) * 100;
	}
	$prev_value = $vcpu->{cpuTime};
	return $usage;
	};
	};
	my $retriever = watch $feeder;

	builder {
	enable "Plack::Middleware::Static",
	path => qr{^/static/}, root => ".";
	mount "/" => sub {
	[ 200,
	[ "Content-Type" => "text/html" ],
	[ get_data_section("html") ],
	];
	};
	mount "/usage" => sub {
	[ 200,
	[ "Content-Type" => "application/json" ],
	[ encode_json $retriever->() ],
	];
	};
	};

	__DATA__

	@@ html
	<!doctype html>
	<html>
	<head>
	<link rel="stylesheet" type="text/css" href="static/jquery.jqplot.css" />
	<script type="text/javascript" src="static/jquery-1.4.1.min.js"></script>
	<script type="text/javascript" src="static/jquery.jqplot.min.js"></script>
	<script type="text/javascript">
	function plot() {
	$.getJSON("/usage", function(data) {
	$("#chartdiv").html("");
	$.jqplot('chartdiv',
	[ data ],
	{ title:'CPU Uasge(%)',
	axes:{ yaxis:{ min:0, max:100 }, xaxis:{ min:-60, max:0 } },
	}
	);
	});
	}
	$(document).ready(function(){
	setInterval(plot, 1000)
	});
	</script>
	</head>
	<body>
	<div id="chartdiv" style="height:400px;width:600px;"></div>
	</body>
	</html>