support andoird

core/bandwidthLimit.go

@@ -0,0 +1,45 @@
+package openp2p
+
+import (
+	"sync"
+	"time"
+)
+
+// BandwidthLimiter ...
+type BandwidthLimiter struct {
+	ts           time.Time
+	bw           int // mbps
+	freeBytes    int // bytes
+	maxFreeBytes int // bytes
+	mtx          sync.Mutex
+}
+
+// mbps
+func newBandwidthLimiter(bw int) *BandwidthLimiter {
+	return &BandwidthLimiter{
+		bw:           bw,
+		ts:           time.Now(),
+		maxFreeBytes: bw * 1024 * 1024 / 8,
+		freeBytes:    bw * 1024 * 1024 / 8,
+	}
+}
+
+// Add ...
+func (bl *BandwidthLimiter) Add(bytes int) {
+	if bl.bw <= 0 {
+		return
+	}
+	bl.mtx.Lock()
+	defer bl.mtx.Unlock()
+	// calc free flow 1000*1000/1024/1024=0.954; 1024*1024/1000/1000=1.048
+	bl.freeBytes += int(time.Since(bl.ts) * time.Duration(bl.bw) / 8 / 954)
+	if bl.freeBytes > bl.maxFreeBytes {
+		bl.freeBytes = bl.maxFreeBytes
+	}
+	bl.freeBytes -= bytes
+	bl.ts = time.Now()
+	if bl.freeBytes < 0 {
+		// sleep for the overflow
+		time.Sleep(time.Millisecond * time.Duration(-bl.freeBytes/(bl.bw*1048/8)))
+	}
+}