forked from quic-go/quic-go
5974c6c113
The length of the data has an influence on the length of the frame (if it contains the data length), and the length can either consume 1 or 2 bytes due to variable length encoding.
278 lines
9.4 KiB
Go
278 lines
9.4 KiB
Go
package wire
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import (
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"bytes"
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"github.com/lucas-clemente/quic-go/internal/protocol"
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"github.com/lucas-clemente/quic-go/internal/utils"
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"github.com/lucas-clemente/quic-go/qerr"
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. "github.com/onsi/ginkgo"
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. "github.com/onsi/gomega"
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)
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var _ = Describe("STREAM frame (for IETF QUIC)", func() {
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Context("when parsing", func() {
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It("parses a frame with OFF bit", func() {
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data := []byte{0x10 ^ 0x4}
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data = append(data, encodeVarInt(0x12345)...) // stream ID
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data = append(data, encodeVarInt(0xdecafbad)...) // offset
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data = append(data, []byte("foobar")...)
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r := bytes.NewReader(data)
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frame, err := ParseStreamFrame(r, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(frame.StreamID).To(Equal(protocol.StreamID(0x12345)))
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Expect(frame.Data).To(Equal([]byte("foobar")))
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Expect(frame.FinBit).To(BeFalse())
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Expect(frame.Offset).To(Equal(protocol.ByteCount(0xdecafbad)))
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Expect(r.Len()).To(BeZero())
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})
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It("respects the LEN when parsing the frame", func() {
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data := []byte{0x10 ^ 0x2}
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data = append(data, encodeVarInt(0x12345)...) // stream ID
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data = append(data, encodeVarInt(4)...) // data length
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data = append(data, []byte("foobar")...)
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r := bytes.NewReader(data)
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frame, err := ParseStreamFrame(r, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(frame.StreamID).To(Equal(protocol.StreamID(0x12345)))
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Expect(frame.Data).To(Equal([]byte("foob")))
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Expect(frame.FinBit).To(BeFalse())
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Expect(frame.Offset).To(BeZero())
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Expect(r.Len()).To(Equal(2))
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})
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It("parses a frame with FIN bit", func() {
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data := []byte{0x10 ^ 0x1}
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data = append(data, encodeVarInt(9)...) // stream ID
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data = append(data, []byte("foobar")...)
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r := bytes.NewReader(data)
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frame, err := ParseStreamFrame(r, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(frame.StreamID).To(Equal(protocol.StreamID(9)))
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Expect(frame.Data).To(Equal([]byte("foobar")))
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Expect(frame.FinBit).To(BeTrue())
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Expect(frame.Offset).To(BeZero())
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Expect(r.Len()).To(BeZero())
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})
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It("rejects empty frames than don't have the FIN bit set", func() {
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data := []byte{0x10}
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data = append(data, encodeVarInt(0x1337)...) // stream ID
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r := bytes.NewReader(data)
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_, err := ParseStreamFrame(r, versionIETFFrames)
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Expect(err).To(MatchError(qerr.EmptyStreamFrameNoFin))
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})
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It("rejects frames that overflow the maximum offset", func() {
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data := []byte{0x10 ^ 0x4}
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data = append(data, encodeVarInt(0x12345)...) // stream ID
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data = append(data, encodeVarInt(uint64(protocol.MaxByteCount-5))...) // offset
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data = append(data, []byte("foobar")...)
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r := bytes.NewReader(data)
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_, err := ParseStreamFrame(r, versionIETFFrames)
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Expect(err).To(MatchError(qerr.Error(qerr.InvalidStreamData, "data overflows maximum offset")))
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})
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It("errors on EOFs", func() {
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data := []byte{0x10 ^ 0x4 ^ 0x2}
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data = append(data, encodeVarInt(0x12345)...) // stream ID
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data = append(data, encodeVarInt(0xdecafbad)...) // offset
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data = append(data, encodeVarInt(6)...) // data length
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data = append(data, []byte("foobar")...)
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_, err := ParseStreamFrame(bytes.NewReader(data), versionIETFFrames)
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Expect(err).NotTo(HaveOccurred())
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for i := range data {
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_, err := ParseStreamFrame(bytes.NewReader(data[0:i]), versionIETFFrames)
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Expect(err).To(HaveOccurred())
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}
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})
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})
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Context("when writing", func() {
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It("writes a frame without offset", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Data: []byte("foobar"),
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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expected := []byte{0x10}
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expected = append(expected, encodeVarInt(0x1337)...) // stream ID
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expected = append(expected, []byte("foobar")...)
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Expect(b.Bytes()).To(Equal(expected))
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})
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It("writes a frame with offset", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0x123456,
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Data: []byte("foobar"),
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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expected := []byte{0x10 ^ 0x4}
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expected = append(expected, encodeVarInt(0x1337)...) // stream ID
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expected = append(expected, encodeVarInt(0x123456)...) // offset
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expected = append(expected, []byte("foobar")...)
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Expect(b.Bytes()).To(Equal(expected))
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})
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It("writes a frame with FIN bit", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0x123456,
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FinBit: true,
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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expected := []byte{0x10 ^ 0x4 ^ 0x1}
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expected = append(expected, encodeVarInt(0x1337)...) // stream ID
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expected = append(expected, encodeVarInt(0x123456)...) // offset
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Expect(b.Bytes()).To(Equal(expected))
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})
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It("writes a frame with data length", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Data: []byte("foobar"),
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DataLenPresent: true,
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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expected := []byte{0x10 ^ 0x2}
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expected = append(expected, encodeVarInt(0x1337)...) // stream ID
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expected = append(expected, encodeVarInt(6)...) // data length
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expected = append(expected, []byte("foobar")...)
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Expect(b.Bytes()).To(Equal(expected))
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})
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It("writes a frame with data length and offset", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Data: []byte("foobar"),
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DataLenPresent: true,
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Offset: 0x123456,
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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expected := []byte{0x10 ^ 0x4 ^ 0x2}
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expected = append(expected, encodeVarInt(0x1337)...) // stream ID
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expected = append(expected, encodeVarInt(0x123456)...) // offset
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expected = append(expected, encodeVarInt(6)...) // data length
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expected = append(expected, []byte("foobar")...)
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Expect(b.Bytes()).To(Equal(expected))
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})
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It("refuses to write an empty frame without FIN", func() {
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f := &StreamFrame{
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StreamID: 0x42,
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Offset: 0x1337,
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}
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b := &bytes.Buffer{}
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err := f.Write(b, versionIETFFrames)
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Expect(err).To(MatchError("StreamFrame: attempting to write empty frame without FIN"))
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})
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})
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Context("length", func() {
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It("has the right length for a frame without offset and data length", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Data: []byte("foobar"),
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}
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Expect(f.MinLength(versionIETFFrames)).To(Equal(1 + utils.VarIntLen(0x1337)))
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})
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It("has the right length for a frame with offset", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0x42,
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Data: []byte("foobar"),
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}
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Expect(f.MinLength(versionIETFFrames)).To(Equal(1 + utils.VarIntLen(0x1337) + utils.VarIntLen(0x42)))
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})
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It("has the right length for a frame with data length", func() {
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0x1234567,
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DataLenPresent: true,
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Data: []byte("foobar"),
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}
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Expect(f.MinLength(versionIETFFrames)).To(Equal(1 + utils.VarIntLen(0x1337) + utils.VarIntLen(0x1234567) + utils.VarIntLen(6)))
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})
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})
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Context("max data length", func() {
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const maxSize = 3000
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It("always returns a data length such that the resulting frame has the right size, if data length is not present", func() {
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data := make([]byte, maxSize)
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0xdeadbeef,
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}
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b := &bytes.Buffer{}
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for i := 1; i < 3000; i++ {
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b.Reset()
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f.Data = nil
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maxDataLen := f.MaxDataLen(protocol.ByteCount(i), versionIETFFrames)
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if maxDataLen == 0 { // 0 means that no valid STREAM_FRAME can be written
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// check that writing a minimal size STREAM_FRAME (i.e. with 1 byte data) is actually larger than the desired size
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f.Data = []byte{0}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(b.Len()).To(BeNumerically(">", i))
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continue
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}
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f.Data = data[:int(maxDataLen)]
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(b.Len()).To(Equal(i))
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}
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})
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It("always returns a data length such that the resulting frame has the right size, if data length is present", func() {
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data := make([]byte, maxSize)
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f := &StreamFrame{
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StreamID: 0x1337,
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Offset: 0xdeadbeef,
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DataLenPresent: true,
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}
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b := &bytes.Buffer{}
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var frameOneByteTooSmallCounter int
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for i := 1; i < 3000; i++ {
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b.Reset()
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f.Data = nil
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maxDataLen := f.MaxDataLen(protocol.ByteCount(i), versionIETFFrames)
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if maxDataLen == 0 { // 0 means that no valid STREAM_FRAME can be written
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// check that writing a minimal size STREAM_FRAME (i.e. with 1 byte data) is actually larger than the desired size
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f.Data = []byte{0}
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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Expect(b.Len()).To(BeNumerically(">", i))
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continue
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}
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f.Data = data[:int(maxDataLen)]
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err := f.Write(b, versionIETFFrames)
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Expect(err).ToNot(HaveOccurred())
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// There's *one* pathological case, where a data length of x can be encoded into 1 byte
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// but a data lengths of x+1 needs 2 bytes
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// In that case, it's impossible to create a STREAM_FRAME of the desired size
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if b.Len() == i-1 {
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frameOneByteTooSmallCounter++
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continue
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}
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Expect(b.Len()).To(Equal(i))
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}
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Expect(frameOneByteTooSmallCounter).To(Equal(1))
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})
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})
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})
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