RenderTextFormat.php

<?php

namespace Prometheus;


class RenderTextFormat implements RendererInterface
{
    const MIME_TYPE = 'text/plain; version=0.0.4';

    /**
     * @param MetricFamilySamples[] $metrics
     * @return string
     */
    public function render(array $metrics)
    {
        usort($metrics, function(MetricFamilySamples $a, MetricFamilySamples $b)
        {
            return strcmp($a->getName(), $b->getName());
        });

        $lines = array();

        foreach ($metrics as $metric) {
            $lines[] = "# HELP " . $metric->getName() . " {$metric->getHelp()}";
            $lines[] = "# TYPE " . $metric->getName() . " {$metric->getType()}";
            foreach ($metric->getSamples() as $sample) {
                $lines[] = $this->renderSample($metric, $sample);
            }
        }
        return implode("\n", $lines) . "\n";
    }

    private function renderSample(MetricFamilySamples $metric, Sample $sample)
    {
        $escapedLabels = array();

        $labelNames = $metric->getLabelNames();
        if ($metric->hasLabelNames() || $sample->hasLabelNames()) {
            $labels = array_combine(array_merge($labelNames, $sample->getLabelNames()), $sample->getLabelValues());
            foreach ($labels as $labelName => $labelValue) {
                $escapedLabels[] = $labelName . '="' . $this->escapeLabelValue($labelValue) . '"';
            }
            return $sample->getName() . '{' . implode(',', $escapedLabels) . '} ' . $sample->getValue();
        }
        return $sample->getName() . ' ' . $sample->getValue();
    }

    private function escapeLabelValue($v)
    {
        $v = str_replace("\\", "\\\\", $v);
        $v = str_replace("\n", "\\n", $v);
        $v = str_replace("\"", "\\\"", $v);
        return $v;
    }
}