Rock your everyday

/***
Function RRD Calculation

@input param1: rrd filename with location e.g /var/lib/mrtg/test.rrd
param2: graphtype e.g daily, weekly, monthly,yearly etc
@output array containing current_in, current_out, average_in, average_out, max_in, max_out, percentile_in, percentile_out values (in bits)

***/
function calculate_rrd ($rrd, $graphtype) {

$data_bits_in = array();
$data_bits_out = array();
$data = array();

if($graphtype == "daily") {
$timelength = "-1d";
$endtime = "-5min"; //endtime is required to avoid last nan values
}
else if ($graphtype == "weekly") {
$timelength = "-1w";
$endtime = "-30min";
}
else if ($graphtype == "monthly") {
$timelength = "-1m";
$endtime = "-120min";
}
else {
$timelength = "-1y";
$endtime = "-1440min";
}
$rrdparams = array ("AVERAGE","--start", $timelength, "--end", $endtime,);

//fetch rrd values using API
$ret = rrd_fetch($rrd, $rrdparams, count($rrdparams));

//start calculation
$data = $ret ['data'];
$data_limit = count ($data)-2;
$data_bits_limit = $data_limit/2;

for ($i = 0; $i < $data_limit;$i++) {
if ($i%2 == 0) {
if (is_nan($data[$i])) $data_bits_in[$k] = 0;
else $data_bits_in[$k] = (int)($data[$i]*8); $k++;
} else {
if (is_nan($data[$i])) $data_bits_out[$j] = 0;
else $data_bits_out[$j] = (int)($data[$i]*8); $j++;
}
}

//get current/average/max value from rrd data

$result['current_in'] = $data_bits_in[$data_bits_limit-1]; $result['current_out'] = $data_bits_out[$data_bits_limit-1]; $result['average_in'] = array_sum ($data_bits_in)/$data_bits_limit; $result['average_out'] = array_sum ($data_bits_out)/$data_bits_limit; $result['max_in'] = max ($data_bits_in);
$result['max_out'] = max ($data_bits_out);

//percentile calculation
sort($data_bits_in);
sort($data_bits_out);
$pos = round($data_bits_limit*0.95);
$result['percentile_in'] = $data_bits_in[$pos];
$result['percentile_out'] = $data_bits_out[$pos];

//return the result
return $result;
}