DogStatsdFormatter.php

Go to the documentation of this file.

<?php
declare( strict_types=1 );
 
namespace Wikimedia\Stats\Formatters;
 
use Wikimedia\Stats\Metrics\MetricInterface;
 
class DogStatsdFormatter implements FormatterInterface {
    public function getFormattedSamples( string $prefix, MetricInterface $metric ): array {
        $output = [];
 
        // append component to prefix if set
        if ( $metric->getComponent() !== '' ) {
            $prefix .= ".{$metric->getComponent()}";
        }
 
        foreach ( $metric->getSamples() as $sample ) {
            // dot-separate prefix, component, and name `prefix.component.name`
            $stat = implode( '.', [ $prefix, $metric->getName() ] );
 
            // merge value with separator `:42`
            $value = ':' . $sample->getValue();
 
            // merge type indicator with separator `|c`
            $type = '|' . $metric->getTypeIndicator();
 
            // blank string if samplerate is 1.0, otherwise add samplerate indicator `|@0.5`
            $sampleRate = $metric->getSampleRate() !== 1.0 ? '|@' . $metric->getSampleRate() : '';
 
            // merge label keys and label values `key:value`
            $labels = [];
            $labelValues = $sample->getLabelValues();
            foreach ( $metric->getLabelKeys() as $i => $labelKey ) {
                $labels[] = $labelKey . ':' . $labelValues[$i];
            }
 
            // combine label kv pairs `|# key1:value1,key2:value2`
            $tags = $labels === [] ? '' : '|#' . implode( ",", $labels );
 
            // combine and append to output `prefix.component.name:42|c|@0.5|#key1:value1,key2:value2`
            $output[] = $stat . $value . $type . $sampleRate . $tags;
        }
        return $output;
    }
}