Check ActorLibCollectUsageStats to reduce utils metric count (#15992)

Author: kardymonds

ydb/library/actors/core/mailbox_lockfree.cpp

@@ -361,7 +361,7 @@ namespace NActors {
         Y_DEBUG_ABORT_UNLESS(GetNextPtr(tail) == nullptr);
 #ifdef ACTORSLIB_COLLECT_EXEC_STATS
         // Mark events as enqueued when usage stats are enabled
-        if (ActorLibCollectUsageStats) {
+         if constexpr (ActorLibCollectUsageStats) {
             for (IEventHandle* ev = head; ev; ev = GetNextPtr(ev)) {
                 if (IActor* actor = FindActor(ev->GetRecipientRewrite().LocalId())) {
                     actor->OnEnqueueEvent(ev->SendTime);

ydb/library/actors/helpers/collector_counters.cpp

@@ -70,8 +70,10 @@ void TActivityStats::Set(const TExecutorThreadStats& stats) {
         *ScheduledEventsByActivityBuckets[i] = scheduled;
         *StuckActorsByActivityBuckets[i] = stuck;
 
-        for (ui32 j = 0; j < 10; ++j) {
-            *UsageByActivityBuckets[i][j] = stats.UsageByActivity[i][j];
+        if constexpr (ActorLibCollectUsageStats) {
+            for (ui32 j = 0; j < 10; ++j) {
+                *UsageByActivityBuckets[i][j] = stats.UsageByActivity[i][j];
+            }
         }
     }
 
@@ -117,8 +119,10 @@ void TActivityStats::InitCountersForActivity(ui32 activityType) {
     StuckActorsByActivityBuckets[activityType] =
         Group->GetSubgroup("sensor", "StuckActorsByActivity")->GetNamedCounter("activity", bucketName, false);
 
-    for (ui32 i = 0; i < 10; ++i) {
-        UsageByActivityBuckets[activityType][i] = Group->GetSubgroup("sensor", "UsageByActivity")->GetSubgroup("bin", ToString(i))->GetNamedCounter("activity", bucketName, false);
+     if constexpr (ActorLibCollectUsageStats) {
+        for (ui32 i = 0; i < 10; ++i) {
+            UsageByActivityBuckets[activityType][i] = Group->GetSubgroup("sensor", "UsageByActivity")->GetSubgroup("bin", ToString(i))->GetNamedCounter("activity", bucketName, false);
+        }
     }
 }