add a Stream class

stream.go

@@ -0,0 +1,60 @@
+package quic
+
+import (
+	"errors"
+	"io"
+
+	"github.com/lucas-clemente/quic-go/frames"
+)
+
+// A Stream assembles the data from StreamFrames and provides a super-convenient Read-Interface
+type Stream struct {
+	StreamFrames   []*frames.StreamFrame
+	DataLen        uint64
+	ReadPosFrameNo int
+	ReadPosInFrame int
+}
+
+// NewStream creates a new Stream
+func NewStream() *Stream {
+	return &Stream{}
+}
+
+func (s *Stream) readByte() (byte, error) {
+	if s.ReadPosInFrame == len(s.StreamFrames[s.ReadPosFrameNo].Data) {
+		s.ReadPosFrameNo++
+		if s.ReadPosFrameNo == len(s.StreamFrames) {
+			return 0, io.EOF
+		}
+		s.ReadPosInFrame = 0
+	}
+	b := s.StreamFrames[s.ReadPosFrameNo].Data[s.ReadPosInFrame]
+	s.ReadPosInFrame++
+	return b, nil
+}
+
+// Read reads data
+func (s *Stream) Read(p []byte) (int, error) {
+	var err error
+	n := 0
+	if c := cap(p); c > 0 {
+		for n < c {
+			p[n], err = s.readByte()
+			n++
+			if err != nil {
+				break
+			}
+		}
+	}
+	return n, nil
+}
+
+// AddStreamFrame adds a new stream frame
+func (s *Stream) AddStreamFrame(frame *frames.StreamFrame) error {
+	if frame.Offset != s.DataLen {
+		return errors.New("Stream: Wrong offset")
+	}
+	s.StreamFrames = append(s.StreamFrames, frame)
+	s.DataLen += uint64(len(frame.Data))
+	return nil
+}

stream_test.go

@@ -0,0 +1,59 @@
+package quic
+
+import (
+	"github.com/lucas-clemente/quic-go/frames"
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Stream", func() {
+	It("reads a single StreamFrame", func() {
+		frame := frames.StreamFrame{
+			Offset: 0,
+			Data:   []byte{0xDE, 0xAD, 0xBE, 0xEF},
+		}
+		stream := NewStream()
+		stream.AddStreamFrame(&frame)
+		b := make([]byte, 4)
+		n, err := stream.Read(b)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(n).To(Equal(4))
+		Expect(stream.DataLen).To(Equal(uint64(4)))
+		Expect(b).To(Equal([]byte{0xDE, 0xAD, 0xBE, 0xEF}))
+	})
+
+	It("assembles multiple StreamFrames", func() {
+		frame1 := frames.StreamFrame{
+			Offset: 0,
+			Data:   []byte{0xDE, 0xAD},
+		}
+		frame2 := frames.StreamFrame{
+			Offset: 2,
+			Data:   []byte{0xBE, 0xEF},
+		}
+		stream := NewStream()
+		stream.AddStreamFrame(&frame1)
+		stream.AddStreamFrame(&frame2)
+		b := make([]byte, 4)
+		n, err := stream.Read(b)
+		Expect(err).ToNot(HaveOccurred())
+		Expect(n).To(Equal(4))
+		Expect(stream.DataLen).To(Equal(uint64(4)))
+		Expect(b).To(Equal([]byte{0xDE, 0xAD, 0xBE, 0xEF}))
+	})
+
+	It("rejects StreamFrames with wrong Offsets", func() {
+		frame1 := frames.StreamFrame{
+			Offset: 0,
+			Data:   []byte{0xDE, 0xAD},
+		}
+		frame2 := frames.StreamFrame{
+			Offset: 1,
+			Data:   []byte{0xBE, 0xEF},
+		}
+		stream := NewStream()
+		stream.AddStreamFrame(&frame1)
+		err := stream.AddStreamFrame(&frame2)
+		Expect(err).To(HaveOccurred())
+	})
+})