对WAF正则缓存增加命中率检查

internal/utils/cachehits/stat.go

@@ -0,0 +1,161 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package cachehits
+
+import (
+	"github.com/TeaOSLab/EdgeNode/internal/goman"
+	"github.com/TeaOSLab/EdgeNode/internal/utils"
+	"github.com/TeaOSLab/EdgeNode/internal/utils/fasttime"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+const countSamples = 10_000
+
+type Item struct {
+	countHits   uint64
+	countCached uint64
+	timestamp   int64
+
+	isGood bool
+	isBad  bool
+}
+
+type Stat struct {
+	goodRatio uint64
+	maxItems  int
+
+	itemMap map[string]*Item // category => *Item
+	mu      *sync.RWMutex
+
+	ticker *time.Ticker
+}
+
+func NewStat(goodRatio uint64) *Stat {
+	if goodRatio == 0 {
+		goodRatio = 5
+	}
+
+	var maxItems = utils.SystemMemoryGB() * 10_000
+	if maxItems <= 0 {
+		maxItems = 100_000
+	}
+
+	var stat = &Stat{
+		goodRatio: goodRatio,
+		itemMap:   map[string]*Item{},
+		mu:        &sync.RWMutex{},
+		ticker:    time.NewTicker(24 * time.Hour),
+		maxItems:  maxItems,
+	}
+
+	goman.New(func() {
+		stat.init()
+	})
+	return stat
+}
+
+func (this *Stat) init() {
+	for range this.ticker.C {
+		var currentTime = fasttime.Now().Unix()
+
+		this.mu.RLock()
+		for _, item := range this.itemMap {
+			if item.timestamp < currentTime-7*24*86400 {
+				// reset
+				item.countHits = 0
+				item.countCached = 1
+				item.timestamp = currentTime
+				item.isGood = false
+				item.isBad = false
+			}
+		}
+		this.mu.RUnlock()
+	}
+}
+
+func (this *Stat) IncreaseCached(category string) {
+	this.mu.RLock()
+	var item = this.itemMap[category]
+	if item != nil {
+		if item.isGood || item.isBad {
+			this.mu.RUnlock()
+			return
+		}
+
+		atomic.AddUint64(&item.countCached, 1)
+		this.mu.RUnlock()
+		return
+	}
+	this.mu.RUnlock()
+
+	this.mu.Lock()
+
+	if len(this.itemMap) > this.maxItems {
+		// remove one randomly
+		for k := range this.itemMap {
+			delete(this.itemMap, k)
+			break
+		}
+	}
+
+	this.itemMap[category] = &Item{
+		countHits:   0,
+		countCached: 1,
+		timestamp:   fasttime.Now().Unix(),
+	}
+	this.mu.Unlock()
+}
+
+func (this *Stat) IncreaseHit(category string) {
+	this.mu.RLock()
+	defer this.mu.RUnlock()
+
+	var item = this.itemMap[category]
+	if item != nil {
+		if item.isGood || item.isBad {
+			return
+		}
+
+		atomic.AddUint64(&item.countHits, 1)
+		return
+	}
+}
+
+func (this *Stat) IsGood(category string) bool {
+	this.mu.RLock()
+	defer func() {
+		this.mu.RUnlock()
+	}()
+
+	var item = this.itemMap[category]
+	if item != nil {
+		if item.isBad {
+			return false
+		}
+		if item.isGood {
+			return true
+		}
+
+		if item.countCached > countSamples {
+			var isGood = item.countHits*100/item.countCached >= this.goodRatio
+			if isGood {
+				item.isGood = true
+			} else {
+				item.isBad = true
+			}
+
+			return isGood
+		}
+	}
+
+	return true
+}
+
+func (this *Stat) Len() int {
+	this.mu.RLock()
+	defer this.mu.RUnlock()
+
+	return len(this.itemMap)
+}