优化代码

internal/caches/max_open_files.go

@@ -13,16 +13,20 @@ const (
 	minOpenFilesValue int32 = 2
 	maxOpenFilesValue int32 = 65535
 
-	modSlow int32 = 1
-	modFast int32 = 2
+	modeSlow int32 = 1
+	modeFast int32 = 2
 )
 
+// MaxOpenFiles max open files manager
 type MaxOpenFiles struct {
 	step         int32
 	maxOpenFiles int32
 	ptr          *int32
 	ticker       *time.Ticker
-	mod          int32
+	mode         int32
+
+	lastOpens    int32
+	currentOpens int32
 }
 
 func NewMaxOpenFiles(step int32) *MaxOpenFiles {
@@ -38,40 +42,51 @@ func NewMaxOpenFiles(step int32) *MaxOpenFiles {
 	}
 	f.ptr = &f.maxOpenFiles
 	f.ticker = time.NewTicker(1 * time.Second)
-	goman.New(func() {
-		for range f.ticker.C {
-			var mod = atomic.LoadInt32(&f.mod)
-			switch mod {
-			case modSlow:
-				// we decrease more quickly, with more steps
-				if atomic.AddInt32(f.ptr, -step*2) <= 0 {
-					atomic.StoreInt32(f.ptr, minOpenFilesValue)
-				}
-			case modFast:
-				if atomic.AddInt32(f.ptr, step) >= maxOpenFilesValue {
-					atomic.StoreInt32(f.ptr, maxOpenFilesValue)
-				}
-			}
-
-			// reset mod
-			atomic.StoreInt32(&f.mod, 0)
-		}
-	})
+	f.init()
 	return f
 }
 
+func (this *MaxOpenFiles) init() {
+	goman.New(func() {
+		for range this.ticker.C {
+			var mod = atomic.LoadInt32(&this.mode)
+			switch mod {
+			case modeSlow:
+				// we decrease more quickly, with more steps
+				if atomic.AddInt32(this.ptr, -this.step*2) <= 0 {
+					atomic.StoreInt32(this.ptr, minOpenFilesValue)
+				}
+			case modeFast:
+				// we increase only when file opens increases
+				var currentOpens = atomic.LoadInt32(&this.currentOpens)
+				if currentOpens > this.lastOpens {
+					if atomic.AddInt32(this.ptr, this.step) >= maxOpenFilesValue {
+						atomic.StoreInt32(this.ptr, maxOpenFilesValue)
+					}
+				}
+				this.lastOpens = currentOpens
+				atomic.StoreInt32(&this.currentOpens, 0)
+			}
+
+			// reset mod
+			atomic.StoreInt32(&this.mode, 0)
+		}
+	})
+}
+
 func (this *MaxOpenFiles) Fast() {
-	if atomic.LoadInt32(&this.mod) == 0 {
-		this.mod = modFast
+	if atomic.LoadInt32(&this.mode) == 0 {
+		this.mode = modeFast
 	}
+	atomic.AddInt32(&this.currentOpens, 1)
 }
 
 func (this *MaxOpenFiles) Slow() {
-	atomic.StoreInt32(&this.mod, modSlow)
+	atomic.StoreInt32(&this.mode, modeSlow)
 }
 
 func (this *MaxOpenFiles) Max() int32 {
-	if atomic.LoadInt32(&this.mod) == modSlow {
+	if atomic.LoadInt32(&this.mode) == modeSlow {
 		return 0
 	}