refactor(metrics): optimize memory allocation in period entries

- Replace heap allocation with stack-allocated array in Entries.Get() method.
- Also refactor uptime module to use value types instead of pointer types.

internal/metrics/period/entries.go

@@ -58,10 +58,14 @@ func (e *Entries[T]) Get() []T {
 	if e.count < maxEntries {
 		return e.entries[:e.count]
 	}
-	res := make([]T, maxEntries)
-	copy(res, e.entries[e.index:])
-	copy(res[maxEntries-e.index:], e.entries[:e.index])
-	return res
+	var res [maxEntries]T
+	if e.index >= e.count {
+		copy(res[:], e.entries[:e.count])
+	} else {
+		copy(res[:], e.entries[e.index:])
+		copy(res[e.count-e.index:], e.entries[:e.index])
+	}
+	return res[:]
 }
 
 func (e *Entries[T]) MarshalJSON() ([]byte, error) {

internal/metrics/uptime/uptime.go

@@ -17,8 +17,8 @@ import (
 
 type (
 	StatusByAlias struct {
-		Map       map[string]*routes.HealthInfo `json:"statuses"`
-		Timestamp int64                         `json:"timestamp"`
+		Map       map[string]routes.HealthInfo `json:"statuses"`
+		Timestamp int64                        `json:"timestamp"`
 	} // @name RouteStatusesByAlias
 	Status struct {
 		Status    types.HealthStatus `json:"status" swaggertype:"string" enums:"healthy,unhealthy,unknown,napping,starting"`
@@ -42,8 +42,8 @@ type (
 
 var Poller = period.NewPoller("uptime", getStatuses, aggregateStatuses)
 
-func getStatuses(ctx context.Context, _ *StatusByAlias) (*StatusByAlias, error) {
-	return &StatusByAlias{
+func getStatuses(ctx context.Context, _ StatusByAlias) (StatusByAlias, error) {
+	return StatusByAlias{
 		Map:       routes.GetHealthInfo(),
 		Timestamp: time.Now().Unix(),
 	}, nil
@@ -57,7 +57,7 @@ func (s *Status) MarshalJSON() ([]byte, error) {
 	})
 }
 
-func aggregateStatuses(entries []*StatusByAlias, query url.Values) (int, Aggregated) {
+func aggregateStatuses(entries []StatusByAlias, query url.Values) (int, Aggregated) {
 	limit := metricsutils.QueryInt(query, "limit", 0)
 	offset := metricsutils.QueryInt(query, "offset", 0)
 	keyword := query.Get("keyword")