[#213] metrics: Refactor engine metrics

Resolve funlen linter for newEngineMetrics function.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/metrics/engine.go

@@ -1,6 +1,8 @@
 package metrics
 
 import (
+	"fmt"
+	"strings"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -26,118 +28,49 @@ type (
 
 const engineSubsystem = "engine"
 
-// nolint: funlen
 func newEngineMetrics() engineMetrics {
-	var (
-		listContainersDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "list_containers_duration",
-			Help:      "Accumulated duration of engine list containers operations",
-		})
-
-		estimateContainerSizeDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "estimate_container_size_duration",
-			Help:      "Accumulated duration of engine container size estimate operations",
-		})
-
-		deleteDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "delete_duration",
-			Help:      "Accumulated duration of engine delete operations",
-		})
-
-		existsDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "exists_duration",
-			Help:      "Accumulated duration of engine exists operations",
-		})
-
-		getDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "get_duration",
-			Help:      "Accumulated duration of engine get operations",
-		})
-
-		headDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "head_duration",
-			Help:      "Accumulated duration of engine head operations",
-		})
-
-		inhumeDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "inhume_duration",
-			Help:      "Accumulated duration of engine inhume operations",
-		})
-
-		putDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "put_duration",
-			Help:      "Accumulated duration of engine put operations",
-		})
-
-		rangeDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "range_duration",
-			Help:      "Accumulated duration of engine range operations",
-		})
-
-		searchDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "search_duration",
-			Help:      "Accumulated duration of engine search operations",
-		})
-
-		listObjectsDuration = prometheus.NewCounter(prometheus.CounterOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "list_objects_duration",
-			Help:      "Accumulated duration of engine list objects operations",
-		})
-
-		containerSize = prometheus.NewGaugeVec(prometheus.GaugeOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "container_size",
-			Help:      "Accumulated size of all objects in a container",
-		}, []string{containerIDLabelKey})
-
-		payloadSize = prometheus.NewGaugeVec(prometheus.GaugeOpts{
-			Namespace: namespace,
-			Subsystem: engineSubsystem,
-			Name:      "payload_size",
-			Help:      "Accumulated size of all objects in a shard",
-		}, []string{shardIDLabelKey})
-	)
-
 	return engineMetrics{
-		listContainersDuration:        listContainersDuration,
+		listContainersDuration:        newEngineMethodDurationCounter("list_containers_"),
-		estimateContainerSizeDuration: estimateContainerSizeDuration,
+		estimateContainerSizeDuration: newEngineCounter("estimate_container_size_duration", "Accumulated duration of engine container size estimate operations"),
-		deleteDuration:                deleteDuration,
+		deleteDuration:                newEngineMethodDurationCounter("delete"),
-		existsDuration:                existsDuration,
+		existsDuration:                newEngineMethodDurationCounter("exists"),
-		getDuration:                   getDuration,
+		getDuration:                   newEngineMethodDurationCounter("get"),
-		headDuration:                  headDuration,
+		headDuration:                  newEngineMethodDurationCounter("head"),
-		inhumeDuration:                inhumeDuration,
+		inhumeDuration:                newEngineMethodDurationCounter("inhume"),
-		putDuration:                   putDuration,
+		putDuration:                   newEngineMethodDurationCounter("put"),
-		rangeDuration:                 rangeDuration,
+		rangeDuration:                 newEngineMethodDurationCounter("range"),
-		searchDuration:                searchDuration,
+		searchDuration:                newEngineMethodDurationCounter("search"),
-		listObjectsDuration:           listObjectsDuration,
+		listObjectsDuration:           newEngineMethodDurationCounter("list_objects"),
-		containerSize:                 *containerSize,
+		containerSize:                 *newEngineGaugeVector("container_size", "Accumulated size of all objects in a container", []string{containerIDLabelKey}),
-		payloadSize:                   *payloadSize,
+		payloadSize:                   *newEngineGaugeVector("payload_size", "Accumulated size of all objects in a shard", []string{shardIDLabelKey}),
 	}
 }
 
+func newEngineCounter(name, help string) prometheus.Counter {
+	return prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: namespace,
+		Subsystem: engineSubsystem,
+		Name:      name,
+		Help:      help,
+	})
+}
+
+func newEngineMethodDurationCounter(method string) prometheus.Counter {
+	return newEngineCounter(
+		fmt.Sprintf("%s_duration", method),
+		fmt.Sprintf("Accumulated duration of engine %s operations", strings.ReplaceAll(method, "_", " ")),
+	)
+}
+
+func newEngineGaugeVector(name, help string, labels []string) *prometheus.GaugeVec {
+	return prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Namespace: namespace,
+		Subsystem: engineSubsystem,
+		Name:      name,
+		Help:      help,
+	}, labels)
+}
+
 func (m engineMetrics) register() {
 	prometheus.MustRegister(m.listContainersDuration)
 	prometheus.MustRegister(m.estimateContainerSizeDuration)