implement parsing and writing of the STOP_SENDING frame

internal/wire/stop_sending_frame.go

@@ -0,0 +1,48 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+	"github.com/lucas-clemente/quic-go/qerr"
+)
+
+// A StopSendingFrame is a STOP_SENDING frame
+type StopSendingFrame struct {
+	StreamID  protocol.StreamID
+	ErrorCode qerr.ErrorCode
+}
+
+// ParseStopSendingFrame parses a STOP_SENDING frame
+func ParseStopSendingFrame(r *bytes.Reader, _ protocol.VersionNumber) (*StopSendingFrame, error) {
+	if _, err := r.ReadByte(); err != nil { // read the TypeByte
+		return nil, err
+	}
+
+	streamID, err := utils.ReadVarInt(r)
+	if err != nil {
+		return nil, err
+	}
+	errorCode, err := utils.BigEndian.ReadUint16(r)
+	if err != nil {
+		return nil, err
+	}
+
+	return &StopSendingFrame{
+		StreamID:  protocol.StreamID(streamID),
+		ErrorCode: qerr.ErrorCode(errorCode),
+	}, nil
+}
+
+// MinLength of a written frame
+func (f *StopSendingFrame) MinLength(_ protocol.VersionNumber) protocol.ByteCount {
+	return 1 + utils.VarIntLen(uint64(f.StreamID)) + 2
+}
+
+func (f *StopSendingFrame) Write(b *bytes.Buffer, _ protocol.VersionNumber) error {
+	b.WriteByte(0x0c)
+	utils.WriteVarInt(b, uint64(f.StreamID))
+	utils.BigEndian.WriteUint16(b, uint16(f.ErrorCode))
+	return nil
+}

internal/wire/stop_sending_frame_test.go

@@ -0,0 +1,64 @@
+package wire
+
+import (
+	"bytes"
+
+	"github.com/lucas-clemente/quic-go/internal/protocol"
+	"github.com/lucas-clemente/quic-go/internal/utils"
+	"github.com/lucas-clemente/quic-go/qerr"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("STOP_SENDING frame", func() {
+	Context("when parsing", func() {
+		It("parses a sample frame", func() {
+			data := []byte{0x0c}
+			data = append(data, encodeVarInt(0xdecafbad)...) // stream ID
+			data = append(data, []byte{0x13, 0x37}...)       // error code
+			b := bytes.NewReader(data)
+			frame, err := ParseStopSendingFrame(b, versionIETFFrames)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(frame.StreamID).To(Equal(protocol.StreamID(0xdecafbad)))
+			Expect(frame.ErrorCode).To(Equal(qerr.ErrorCode(0x1337)))
+			Expect(b.Len()).To(BeZero())
+		})
+
+		It("errors on EOFs", func() {
+			data := []byte{0x0c}
+			data = append(data, encodeVarInt(0xdecafbad)...) // stream ID
+			data = append(data, []byte{0x13, 0x37}...)       // error code
+			_, err := ParseStopSendingFrame(bytes.NewReader(data), versionIETFFrames)
+			Expect(err).NotTo(HaveOccurred())
+			for i := range data {
+				_, err := ParseStopSendingFrame(bytes.NewReader(data[:i]), versionIETFFrames)
+				Expect(err).To(HaveOccurred())
+			}
+		})
+	})
+
+	Context("when writing", func() {
+		It("writes", func() {
+			frame := &StopSendingFrame{
+				StreamID:  0xdeadbeefcafe,
+				ErrorCode: 0x10,
+			}
+			buf := &bytes.Buffer{}
+			err := frame.Write(buf, versionIETFFrames)
+			Expect(err).ToNot(HaveOccurred())
+			expected := []byte{0x0c}
+			expected = append(expected, encodeVarInt(0xdeadbeefcafe)...)
+			expected = append(expected, []byte{0x0, 0x10}...)
+			Expect(buf.Bytes()).To(Equal(expected))
+		})
+
+		It("has the correct min length", func() {
+			frame := &StopSendingFrame{
+				StreamID:  0xdeadbeef,
+				ErrorCode: 0x10,
+			}
+			Expect(frame.MinLength(versionIETFFrames)).To(Equal(1 + 2 + utils.VarIntLen(0xdeadbeef)))
+		})
+	})
+})