[#1410] engine: Provide the default implementation to MetricsRegister

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

pkg/local_object_storage/engine/metrics.go

@@ -68,3 +68,48 @@ func (m *gcMetrics) AddExpiredObjectCollectionDuration(d time.Duration, success
 func (m *gcMetrics) AddInhumedObjectCount(count uint64, objectType string) {
 	m.storage.AddInhumedObjectCount(m.shardID, count, objectType)
 }
+
+type (
+	noopMetrics           struct{}
+	noopWriteCacheMetrics struct{}
+	noopGCMetrics         struct{}
+)
+
+var (
+	_ MetricRegister            = noopMetrics{}
+	_ metrics.WriteCacheMetrics = noopWriteCacheMetrics{}
+	_ metrics.GCMetrics         = noopGCMetrics{}
+)
+
+func (noopMetrics) AddMethodDuration(string, time.Duration)                  {}
+func (noopMetrics) SetObjectCounter(string, string, uint64)                  {}
+func (noopMetrics) AddToObjectCounter(string, string, int)                   {}
+func (noopMetrics) SetMode(string, mode.Mode)                                {}
+func (noopMetrics) AddToContainerSize(string, int64)                         {}
+func (noopMetrics) DeleteContainerSize(string)                               {}
+func (noopMetrics) DeleteContainerCount(string)                              {}
+func (noopMetrics) AddToPayloadCounter(string, int64)                        {}
+func (noopMetrics) IncErrorCounter(string)                                   {}
+func (noopMetrics) ClearErrorCounter(string)                                 {}
+func (noopMetrics) DeleteShardMetrics(string)                                {}
+func (noopMetrics) SetContainerObjectCounter(string, string, string, uint64) {}
+func (noopMetrics) IncContainerObjectCounter(string, string, string)         {}
+func (noopMetrics) SubContainerObjectCounter(string, string, string, uint64) {}
+func (noopMetrics) IncRefillObjectsCount(string, string, int, bool)          {}
+func (noopMetrics) SetRefillPercent(string, string, uint32)                  {}
+func (noopMetrics) SetRefillStatus(string, string, string)                   {}
+func (noopMetrics) SetEvacuationInProgress(string, bool)                     {}
+func (noopMetrics) WriteCache() metrics.WriteCacheMetrics                    { return noopWriteCacheMetrics{} }
+func (noopMetrics) GC() metrics.GCMetrics                                    { return noopGCMetrics{} }
+
+func (noopWriteCacheMetrics) AddMethodDuration(string, string, string, string, bool, time.Duration) {}
+func (noopWriteCacheMetrics) SetActualCount(string, string, string, uint64)                         {}
+func (noopWriteCacheMetrics) SetEstimateSize(string, string, string, uint64)                        {}
+func (noopWriteCacheMetrics) SetMode(string, string)                                                {}
+func (noopWriteCacheMetrics) IncOperationCounter(string, string, string, string, metrics.NullBool)  {}
+func (noopWriteCacheMetrics) Close(string, string)                                                  {}
+
+func (noopGCMetrics) AddRunDuration(string, time.Duration, bool)                             {}
+func (noopGCMetrics) AddDeletedCount(string, uint64, uint64)                                 {}
+func (noopGCMetrics) AddExpiredObjectCollectionDuration(string, time.Duration, bool, string) {}
+func (noopGCMetrics) AddInhumedObjectCount(string, uint64, string)                           {}