source: noc/html/rrdgraph.lib.php @ 113

<?php
/*
(c)2006 Joe Presbrey <presbrey@mit.edu>
inspired by parts of nagiosgraph in Perl
*/

function hashcolor($x) {
  $x .= 'x'; $c=1;
  for($i = 0; $i < strlen($x); $i++) { $c=(51*$c+ord($x{$i}))%216; }
  $h = array(51*floor($c/36), 51*floor($c/6%6), 51*($c%6));
  $i = $n = $m = 0;
  for($i = 0; $i <= 2; $i++) {
    if ($h[$i] < $h[$m]) $m = $i;
    if ($h[$i] > $h[$n]) $n = $i;
  }
  if ($h[$m]>102) $h[$m] = 102;
  if ($h[$n]<153) $h[$n] = 153;
  $n = ($h[2])+($h[1]*256)+$h[0]*256*256;
  $c = sprintf("%06X", ($h[2])+($h[1]*256)+$h[0]*256*256);
  return $c;
}

function findRRD($host, $service) {
        if (isset($GLOBALS['RRD_PATH'])) {
                $rrd = $GLOBALS['RRD_PATH'];
        } else {
                $rrd = dirname(__FILE__);
        }
        $f = glob("$rrd/{$host}_{$service}_*.rrd");
        if (count($f)) {
                $o = array_shift($f);
        } else {
                $host = str_replace('-','%2D',rawurlencode($host));
                $service = str_replace('-','%2D',rawurlencode($service));
                $f = glob("$rrd/{$host}_{$service}_*.rrd");
                if (count($f)) {
                        $o = array_shift($f);
                } else {
                        $f = glob("$rrd/{$host}_{$service}*.rrd");
                        if (count($f))
                                $o = array_shift($f);
                }
        }
        $p = realpath($o);
        if (strlen($p)>strlen($host)+strlen($service)) {
                if (preg_match_all('/([^_]+)_([^_]+)_(.+).rrd/iU', basename($p), $m)) {
                        return array($p, $m[1][0], $m[2][0], $m[3][0]);
                }
        }
}

function graphInfo($file) {
        $rrdinfo = `rrdtool info $file`;
        preg_match_all('/ds\[([^\]]*)\]\./',$rrdinfo,$ds);
        $lines = array_unique($ds[1]);
        //sort($lines);
        return $lines;
}

function makeDefs($file, $ignores=array(), $oneHost=true) {
        $info = graphInfo($file[0]);
        $defs = array();
        $def = 'DEF:$dj=$file:$di:AVERAGE' .
               ' LINE2:$dj#$c:$dj' .
               ' GPRINT:$dj:MAX:Max\\\\:\\ %6.2lf%s' .
               ' GPRINT:$dj:AVERAGE:Avg\\\\:\\ %6.2lf%s' .
               ' GPRINT:$dj:MIN:Min\\\\:\\ %6.2lf%s' .
               ' GPRINT:$dj:LAST:Cur\\\\:\\ %6.2lf%s\\\\n';
        foreach($info as $sv) {
                if (in_array(strtolower($sv), $ignores)) continue;
                $d = str_replace('$di',$sv,$def);
                if ($oneHost) {
                        $d = str_replace('$dj',$sv,$d);
                        $d = str_replace('$c',hashcolor($sv),$d);
                } else {
                        $d = str_replace('$dj',urldecode($file[1]).'_'.$sv,$d);
                        $d = str_replace('$c',hashcolor(md5($file[0].$sv)),$d);
                }
                $d = str_replace('$file',$file[0],$d);
                $defs[] = $d;
        }
        return implode(' ',$defs);
}

function outputGraph($hosts, $service, $time, $opts = array()) {
        if (!is_array($hosts)) $hosts = array($hosts);
        $oneHost = count($hosts)<=1;
//      if (!is_array($services)) $services = array($services);
        $defs = array();
        $args = array();
        $files = array();
        foreach($hosts as $host) {
                $file = findRRD($host, $service);
                if (is_array($file) && strlen($file[0])) $files[] = $file;
        }
        foreach($files as $file) {
                if (isset($GLOBALS['RRD_IGNORE'])
                   && isset($GLOBALS['RRD_IGNORE'][strtolower($service)])) {
                        $def = makeDefs($file, $GLOBALS['RRD_IGNORE'][strtolower($service)], $oneHost);
                } else {
                        $def = makeDefs($file, array(), $oneHost);
                }
                if (strlen($def)) $defs[] = $def;
        }

        if (count($opts))
                extract($opts);
        if (isset($geom)) {
                if (isset($geom[0]))
                        $args[] = '-w '.$geom[0];
                if (isset($geom[1]))
                        $args[] = '-h '.$geom[1];
        }
        if (isset($legend) && !$legend) {
                $args[] = '-g';
        }
        if (isset($title)) {
                if (count($files)) {
                        list($fhost, $fservice, $fdb) = array_slice(explode('_',basename($files[0][0])),0,3);
                        if ($oneHost) {
                                $title = str_replace('%h', urldecode($fhost), $title);
                                $title = str_replace('%s', urldecode($fservice), $title);
                        } else {
                                $title = str_replace('%h', implode(',',$hosts), $title);
                                $title = str_replace('%s', urldecode($service), $title);
                        }
                }
                $title = escapeshellarg($title);
                if (strlen($title)) $args[] = "-v$title";
        }

        if (count($defs)) {
                $defs = implode(' ', $defs);
                if (count($args))
                        $argstr = implode(' ', $args);
                $cmd = "rrdtool graph - -a PNG --start -$time $defs $argstr";
                $data = `$cmd`;
                if (strlen($data)>0) {
                        header('Content-Type: image/png');
                        echo $data;
                        exit;
                } else {
                        echo "failed: $cmd";
                }
        }
}

//outputGraph('better-mousetrap', 'DISK: /', 192000);