LibreNMS/RRD/RrdDefinition.php
<?php
/**
* RrdDefinition.php
*
* Build a RRD definition.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
* @link https://www.librenms.org
*
* @copyright 2017 Tony Murray
* @author Tony Murray <murraytony@gmail.com>
*/
namespace LibreNMS\RRD;
use LibreNMS\Config;
use LibreNMS\Exceptions\InvalidRrdTypeException;
class RrdDefinition
{
private static $types = ['GAUGE', 'DERIVE', 'COUNTER', 'ABSOLUTE', 'DCOUNTER', 'DDERIVE'];
private $dataSets = [];
private $sources = [];
private $invalid_source = [];
private $skipNameCheck = false;
/**
* Make a new empty RrdDefinition
*/
public static function make()
{
return new self();
}
/**
* Add a dataset to this definition.
* See https://oss.oetiker.ch/rrdtool/doc/rrdcreate.en.html for more information.
*
* @param string $name Textual name for this dataset. Must be [a-zA-Z0-9_], max length 19.
* @param string $type GAUGE | COUNTER | DERIVE | DCOUNTER | DDERIVE | ABSOLUTE.
* @param int $min Minimum allowed value. null means undefined.
* @param int $max Maximum allowed value. null means undefined.
* @param int $heartbeat Heartbeat for this dataset. Uses the global setting if null.
* @param string $source_ds Dataset to copy data from an existing rrd file
* @param string $source_file File to copy data from (may be ommitted copy from the current file)
* @return RrdDefinition
*/
public function addDataset($name, $type, $min = null, $max = null, $heartbeat = null, $source_ds = null, $source_file = null)
{
if (empty($name)) {
d_echo('DS must be set to a non-empty string.');
}
$name = $this->escapeName($name);
$this->dataSets[$name] = [
'name' => $name,
'type' => $this->checkType($type),
'hb' => is_null($heartbeat) ? Config::get('rrd.heartbeat') : $heartbeat,
'min' => is_null($min) ? 'U' : $min,
'max' => is_null($max) ? 'U' : $max,
'source_ds' => $source_ds,
'source_file' => $source_file,
];
return $this;
}
/**
* Get the RRD Definition as it would be passed to rrdtool
*
* @return string
*/
public function __toString()
{
$def = array_reduce($this->dataSets, function ($carry, $ds) {
$name = $ds['name'] . $this->createSource($ds['source_ds'], $ds['source_file']);
return $carry . "DS:$name:{$ds['type']}:{$ds['hb']}:{$ds['min']}:{$ds['max']} ";
}, '');
$sources = implode(' ', array_map(fn ($s) => "--source $s ", $this->sources));
return $sources . $def;
}
/**
* Check if the give dataset name is valid for this definition
*
* @param string $name
* @return bool
*/
public function isValidDataset($name)
{
return $this->skipNameCheck || isset($this->dataSets[$this->escapeName($name)]);
}
/**
* Disable checking if the name is valid for incoming data and just assign values
* based on order
*
* @return $this
*/
public function disableNameChecking()
{
$this->skipNameCheck = true;
return $this;
}
private function createSource(?string $ds, ?string $file): string
{
if (empty($ds)) {
return '';
}
$output = '=' . $ds;
// if is file given, find or add it to the sources list
if ($file) {
$index = array_search($file, $this->sources);
if ($index === false) {
// check if source rrd exists and cache failures
// using file_exists because source does not seem to support rrdcached
// so this will only work if we have file access to the old rrd file
if (isset($this->invalid_source[$file]) || ! file_exists($file)) {
$this->invalid_source[$file] = true;
return ''; // skip source if file does not exist
}
$this->sources[] = $file;
end($this->sources);
$index = key($this->sources);
}
$output .= '[' . ($index + 1) . ']'; // rrdcreate sources are 1 based
}
return $output;
}
/**
* Check that the data set type is valid.
*
* @param string $type
* @return mixed
*
* @throws InvalidRrdTypeException
*/
private function checkType($type)
{
if (! in_array($type, self::$types)) {
$msg = "$type is not valid, must be: " . implode(' | ', self::$types);
throw new InvalidRrdTypeException($msg);
}
return $type;
}
/**
* Remove all invalid characters from the name and truncate to 19 characters.
*
* @param string $name
* @return string
*/
private function escapeName($name)
{
$name = preg_replace('/[^a-zA-Z0-9_\-]/', '', $name);
return substr($name, 0, 19);
}
}