statsd_exporter/pkg/metrics/metrics.go~

package metrics

import (
	"github.com/prometheus/client_golang/prometheus"
)

type metricType int

const (
	CounterMetricType metricType = iota
	GaugeMetricType
	SummaryMetricType
	HistogramMetricType
)

type nameHash uint64
type valueHash uint64
type labelHash struct {
	// This is a hash over the label names
	names nameHash
	// This is a hash over the label names + label values
	values valueHash
}

type metricHolder interface{}

type vectorHolder interface {
	Delete(label prometheus.Labels) bool
}

type vector struct {
	holder   vectorHolder
	refCount uint64
}

type metric struct {
	metricType metricType
	// Vectors key is the hash of the label names
	vectors map[nameHash]*vector
	// Metrics key is a hash of the label names + label values
	metrics map[valueHash]*registeredMetric
}