Use MetricAggregator interface for time windows

Author: Fedosin

api/interfaces.go

@@ -80,6 +80,9 @@ type MetricAggregator interface {
 
 	// IsEmpty returns true if no data exists in the window.
 	IsEmpty(now time.Time) bool
+
+	// ResizeWindow resizes the window to the given duration.
+	ResizeWindow(w time.Duration)
 }
 
 // Reporter reports autoscaler metrics for monitoring.

manager/scaler.go

@@ -25,21 +25,13 @@ import (
 	"github.com/Fedosin/libkpa/metrics"
 )
 
-// timeWindowInterface provides a common interface for TimeWindow operations
-type timeWindowInterface interface {
-	Record(now time.Time, value float64)
-	WindowAverage(now time.Time) float64
-	IsEmpty(now time.Time) bool
-	ResizeWindow(w time.Duration)
-}
-
 // Scaler represents a single autoscaler instance that combines metric aggregation
 // with a sliding window autoscaling algorithm.
 type Scaler struct {
 	name             string
 	algorithm        *algorithm.SlidingWindowAutoscaler
-	stableAggregator timeWindowInterface
-	panicAggregator  timeWindowInterface
+	stableAggregator api.MetricAggregator
+	panicAggregator  api.MetricAggregator
 }
 
 // NewScaler creates a new Scaler instance with the specified configuration.
@@ -68,7 +60,7 @@ func NewScaler(
 	granularity := time.Second
 
 	// Create the appropriate metric aggregators based on algoType
-	var stableAgg, panicAgg timeWindowInterface
+	var stableAgg, panicAgg api.MetricAggregator
 	switch algoType {
 	case "linear":
 		stableAgg, err = metrics.NewTimeWindow(cfg.StableWindow, granularity)

metrics/time_window.go

@@ -22,6 +22,8 @@ import (
 	"math"
 	"sync"
 	"time"
+
+	"github.com/Fedosin/libkpa/api"
 )
 
 const (
@@ -64,6 +66,8 @@ type TimeWindow struct {
 	windowTotal float64
 }
 
+var _ api.MetricAggregator = (*TimeWindow)(nil)
+
 // String implements the Stringer interface.
 func (t *TimeWindow) String() string {
 	return fmt.Sprintf("%v", t.buckets)

metrics/weighted_time_window.go

@@ -19,6 +19,8 @@ package metrics
 import (
 	"math"
 	"time"
+
+	"github.com/Fedosin/libkpa/api"
 )
 
 // WeightedTimeWindow is the implementation of buckets, that
@@ -33,6 +35,8 @@ type WeightedTimeWindow struct {
 	smoothingCoeff float64
 }
 
+var _ api.MetricAggregator = (*WeightedTimeWindow)(nil)
+
 // NewWeightedTimeWindow generates a new WeightedTimeWindow with the given
 // granularity.
 func NewWeightedTimeWindow(window, granularity time.Duration) (*WeightedTimeWindow, error) {