add congestion.Bandwidth

congestion/bandwidth.go

@@ -0,0 +1,22 @@
+package congestion
+
+import "time"
+
+// Bandwidth of a connection
+type Bandwidth uint64
+
+const (
+	// BitsPerSecond is 1 bit per second
+	BitsPerSecond Bandwidth = 1
+	// KBitsPerSecond is 1000 bits per second
+	KBitsPerSecond = 1000 * BitsPerSecond
+	// BytesPerSecond is 1 byte per second
+	BytesPerSecond = 8 * BitsPerSecond
+	// KBytesPerSecond is 1000 bytes per second
+	KBytesPerSecond = 1000 * BytesPerSecond
+)
+
+// BandwidthFromDelta calculates the bandwidth from a number of bytes and a time delta
+func BandwidthFromDelta(bytes uint64, delta time.Duration) Bandwidth {
+	return Bandwidth(bytes) * Bandwidth(time.Second) / Bandwidth(delta) * BytesPerSecond
+}

congestion/bandwidth_test.go

@@ -0,0 +1,15 @@
+package congestion_test
+
+import (
+	"time"
+
+	"github.com/lucas-clemente/quic-go/congestion"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Bandwidth", func() {
+	It("converts from time delta", func() {
+		Expect(congestion.BandwidthFromDelta(1, time.Millisecond)).To(Equal(1000 * congestion.BytesPerSecond))
+	})
+})