1.4.5.2

EdgeNode/internal/utils/counters/item.go

@@ -0,0 +1,132 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package counters
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/utils/fasttime"
+)
+
+const spanMaxValue = 10_000_000
+const maxSpans = 10
+
+type Item[T SupportedUIntType] struct {
+	spans          [maxSpans + 1]T
+	lastUpdateTime int64
+	lifeSeconds    int64
+	spanSeconds    int64
+}
+
+func NewItem[T SupportedUIntType](lifeSeconds int) Item[T] {
+	if lifeSeconds <= 0 {
+		lifeSeconds = 60
+	}
+	var spanSeconds = lifeSeconds / maxSpans
+	if spanSeconds < 1 {
+		spanSeconds = 1
+	} else if lifeSeconds > maxSpans && lifeSeconds%maxSpans != 0 {
+		spanSeconds++
+	}
+
+	return Item[T]{
+		lifeSeconds:    int64(lifeSeconds),
+		spanSeconds:    int64(spanSeconds),
+		lastUpdateTime: fasttime.Now().Unix(),
+	}
+}
+
+func (this *Item[T]) Increase() (result T) {
+	var currentTime = fasttime.Now().Unix()
+	var currentSpanIndex = this.calculateSpanIndex(currentTime)
+
+	// return quickly
+	if this.lastUpdateTime == currentTime {
+		if this.spans[currentSpanIndex] < spanMaxValue {
+			this.spans[currentSpanIndex]++
+		}
+		for _, count := range this.spans {
+			result += count
+		}
+		return
+	}
+
+	if this.lastUpdateTime > 0 {
+		if currentTime-this.lastUpdateTime > this.lifeSeconds {
+			for index := range this.spans {
+				this.spans[index] = 0
+			}
+		} else {
+			var lastSpanIndex = this.calculateSpanIndex(this.lastUpdateTime)
+
+			if lastSpanIndex != currentSpanIndex {
+				var countSpans = len(this.spans)
+
+				// reset values between LAST and CURRENT
+				for index := lastSpanIndex + 1; ; index++ {
+					var realIndex = index % countSpans
+					this.spans[realIndex] = 0
+					if realIndex == currentSpanIndex {
+						break
+					}
+				}
+			}
+		}
+	}
+
+	if this.spans[currentSpanIndex] < spanMaxValue {
+		this.spans[currentSpanIndex]++
+	}
+	this.lastUpdateTime = currentTime
+
+	for _, count := range this.spans {
+		result += count
+	}
+
+	return
+}
+
+func (this *Item[T]) Sum() (result T) {
+	if this.lastUpdateTime == 0 {
+		return 0
+	}
+
+	var currentTime = fasttime.Now().Unix()
+	var currentSpanIndex = this.calculateSpanIndex(currentTime)
+
+	if currentTime-this.lastUpdateTime > this.lifeSeconds {
+		return 0
+	} else {
+		var lastSpanIndex = this.calculateSpanIndex(this.lastUpdateTime)
+		var countSpans = len(this.spans)
+		for index := currentSpanIndex + 1; ; index++ {
+			var realIndex = index % countSpans
+			result += this.spans[realIndex]
+			if realIndex == lastSpanIndex {
+				break
+			}
+		}
+	}
+
+	return result
+}
+
+func (this *Item[T]) Reset() {
+	for index := range this.spans {
+		this.spans[index] = 0
+	}
+}
+
+func (this *Item[T]) IsExpired(currentTime int64) bool {
+	return this.lastUpdateTime < currentTime-this.lifeSeconds-this.spanSeconds
+}
+
+func (this *Item[T]) calculateSpanIndex(timestamp int64) int {
+	var index = int(timestamp % this.lifeSeconds / this.spanSeconds)
+	if index > maxSpans-1 {
+		return maxSpans - 1
+	}
+	return index
+}
+
+func (this *Item[T]) IsOk() bool {
+	return this.lifeSeconds > 0
+}