Initial commit (code only without large binaries)

EdgeNode/internal/utils/fs/limiter.go

@@ -0,0 +1,100 @@
+// Copyright 2024 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package fsutils
+
+import (
+	"runtime"
+	"time"
+)
+
+var maxThreads = runtime.NumCPU()
+var WriterLimiter = NewLimiter(max(maxThreads*16, 32))
+var ReaderLimiter = NewLimiter(max(maxThreads*16, 32))
+
+type Limiter struct {
+	threads      chan struct{}
+	count        int
+	countDefault int
+	timers       chan *time.Timer
+}
+
+func NewLimiter(threads int) *Limiter {
+	if threads < 32 {
+		threads = 32
+	}
+	if threads > 1024 {
+		threads = 1024
+	}
+
+	var threadsChan = make(chan struct{}, threads)
+	for i := 0; i < threads; i++ {
+		threadsChan <- struct{}{}
+	}
+
+	return &Limiter{
+		countDefault: threads,
+		count:        threads,
+		threads:      threadsChan,
+		timers:       make(chan *time.Timer, 4096),
+	}
+}
+
+func (this *Limiter) SetThreads(newThreads int) {
+	if newThreads <= 0 {
+		newThreads = this.countDefault
+	}
+
+	if newThreads != this.count {
+		var threadsChan = make(chan struct{}, newThreads)
+		for i := 0; i < newThreads; i++ {
+			threadsChan <- struct{}{}
+		}
+
+		this.threads = threadsChan
+		this.count = newThreads
+	}
+}
+
+func (this *Limiter) Ack() {
+	<-this.threads
+}
+
+func (this *Limiter) TryAck() bool {
+	const timeoutDuration = 500 * time.Millisecond
+
+	var timeout *time.Timer
+	select {
+	case timeout = <-this.timers:
+		timeout.Reset(timeoutDuration)
+	default:
+		timeout = time.NewTimer(timeoutDuration)
+	}
+
+	defer func() {
+		timeout.Stop()
+
+		select {
+		case this.timers <- timeout:
+		default:
+		}
+	}()
+
+	select {
+	case <-this.threads:
+		return true
+	case <-timeout.C:
+		return false
+	}
+}
+
+func (this *Limiter) Release() {
+	select {
+	case this.threads <- struct{}{}:
+	default:
+		// 由于容量可能有变化，这里忽略多余的thread
+	}
+}
+
+func (this *Limiter) FreeThreads() int {
+	return len(this.threads)
+}