simplify session by moving packet packing to separate class

packet_packer_test.go

@@ -0,0 +1,91 @@
+package quic
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/crypto"
+	"github.com/lucas-clemente/quic-go/frames"
+	"github.com/lucas-clemente/quic-go/protocol"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Packet packer", func() {
+	var (
+		packer *packetPacker
+	)
+
+	BeforeEach(func() {
+		aead := &crypto.NullAEAD{}
+		packer = &packetPacker{aead: aead}
+	})
+
+	It("returns nil when no packet is queued", func() {
+		p, err := packer.PackPacket()
+		Expect(p).To(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	It("packs single packets", func() {
+		f := &frames.AckFrame{}
+		packer.AddFrame(f)
+		p, err := packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+		b := &bytes.Buffer{}
+		f.Write(b)
+		Expect(p.payload).To(Equal(b.Bytes()))
+		Expect(p.raw).To(ContainSubstring(string(b.Bytes())))
+	})
+
+	It("packs multiple frames into single packet", func() {
+		f1 := &frames.AckFrame{LargestObserved: 1}
+		f2 := &frames.AckFrame{LargestObserved: 2}
+		packer.AddFrame(f1)
+		packer.AddFrame(f2)
+		p, err := packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+		b := &bytes.Buffer{}
+		f1.Write(b)
+		f2.Write(b)
+		Expect(p.payload).To(Equal(b.Bytes()))
+		Expect(p.raw).To(ContainSubstring(string(b.Bytes())))
+	})
+
+	It("packs many normal frames into 2 packets", func() {
+		f := &frames.AckFrame{LargestObserved: 1}
+		b := &bytes.Buffer{}
+		f.Write(b)
+		for i := 0; i <= (protocol.MaxFrameSize-1)/b.Len()+1; i++ {
+			packer.AddFrame(f)
+		}
+		p, err := packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+		Expect(len(p.payload) % b.Len()).To(BeZero())
+		Expect(p.raw).To(ContainSubstring(string(b.Bytes())))
+		p, err = packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+		Expect(p.payload).To(Equal(b.Bytes()))
+		Expect(p.raw).To(ContainSubstring(string(b.Bytes())))
+	})
+
+	It("splits stream frames", func() {
+		f := &frames.StreamFrame{
+			Data:   bytes.Repeat([]byte{'f'}, protocol.MaxFrameSize),
+			Offset: 1,
+		}
+		b := &bytes.Buffer{}
+		f.Write(b)
+		packer.AddFrame(f)
+		p, err := packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(len(p.raw)).To(Equal(protocol.MaxPacketSize))
+		Expect(err).ToNot(HaveOccurred())
+		p, err = packer.PackPacket()
+		Expect(p).ToNot(BeNil())
+		Expect(err).ToNot(HaveOccurred())
+	})
+})