use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/lucas-clemente/quic-go/internal/congestion/bandwidth.go

@@ -0,0 +1,22 @@
+package congestion
+
+import (
+	"time"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+)
+
+// Bandwidth of a connection
+type Bandwidth uint64
+
+const (
+	// BitsPerSecond is 1 bit per second
+	BitsPerSecond Bandwidth = 1
+	// BytesPerSecond is 1 byte per second
+	BytesPerSecond = 8 * BitsPerSecond
+)
+
+// BandwidthFromDelta calculates the bandwidth from a number of bytes and a time delta
+func BandwidthFromDelta(bytes protocol.ByteCount, delta time.Duration) Bandwidth {
+	return Bandwidth(bytes) * Bandwidth(time.Second) / Bandwidth(delta) * BytesPerSecond
+}