copy AckHandler package

ackhandlernew/entropy_accumulator.go

@@ -0,0 +1,23 @@
+package ackhandlernew
+
+import "github.com/lucas-clemente/quic-go/protocol"
+
+// EntropyAccumulator accumulates the entropy according to the QUIC docs
+type EntropyAccumulator byte
+
+// Add the contribution of the entropy flag of a given packet number
+func (e *EntropyAccumulator) Add(packetNumber protocol.PacketNumber, entropyFlag bool) {
+	if entropyFlag {
+		(*e) ^= 0x01 << (packetNumber % 8)
+	}
+}
+
+// Subtract the contribution of the entropy flag of a given packet number
+func (e *EntropyAccumulator) Subtract(packetNumber protocol.PacketNumber, entropyFlag bool) {
+	e.Add(packetNumber, entropyFlag)
+}
+
+// Get the byte of entropy
+func (e *EntropyAccumulator) Get() byte {
+	return byte(*e)
+}