forked from quic-go/quic-go
3a12a898a5
The new parsing function is vastly faster than the combination of header and extended header parsing: BenchmarkShortHeaderParsing-10 44192314 26.79 ns/op 48 B/op 1 allocs/op BenchmarkShortHeaderParsingOld-10 12627363 99.99 ns/op 228 B/op 3 allocs/op
74 lines
2.0 KiB
Go
74 lines
2.0 KiB
Go
package wire
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import (
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"errors"
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"fmt"
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"io"
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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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)
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type ShortHeader struct {
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DestConnectionID protocol.ConnectionID
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PacketNumber protocol.PacketNumber
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PacketNumberLen protocol.PacketNumberLen
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KeyPhase protocol.KeyPhaseBit
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}
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func ParseShortHeader(data []byte, connIDLen int) (*ShortHeader, error) {
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if len(data) == 0 {
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return nil, io.EOF
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}
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if data[0]&0x80 > 0 {
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return nil, errors.New("not a short header packet")
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}
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if data[0]&0x40 == 0 {
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return nil, errors.New("not a QUIC packet")
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}
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pnLen := protocol.PacketNumberLen(data[0]&0b11) + 1
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if len(data) < 1+int(pnLen)+connIDLen {
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return nil, io.EOF
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}
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destConnID := protocol.ParseConnectionID(data[1 : 1+connIDLen])
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pos := 1 + connIDLen
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var pn protocol.PacketNumber
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switch pnLen {
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case protocol.PacketNumberLen1:
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pn = protocol.PacketNumber(data[pos])
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case protocol.PacketNumberLen2:
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pn = protocol.PacketNumber(utils.BigEndian.Uint16(data[pos : pos+2]))
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case protocol.PacketNumberLen3:
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pn = protocol.PacketNumber(utils.BigEndian.Uint24(data[pos : pos+3]))
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case protocol.PacketNumberLen4:
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pn = protocol.PacketNumber(utils.BigEndian.Uint32(data[pos : pos+4]))
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default:
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return nil, fmt.Errorf("invalid packet number length: %d", pnLen)
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}
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kp := protocol.KeyPhaseZero
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if data[0]&0b100 > 0 {
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kp = protocol.KeyPhaseOne
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}
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var err error
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if data[0]&0x18 != 0 {
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err = ErrInvalidReservedBits
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}
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return &ShortHeader{
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DestConnectionID: destConnID,
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PacketNumber: pn,
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PacketNumberLen: pnLen,
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KeyPhase: kp,
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}, err
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}
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func (h *ShortHeader) Len() protocol.ByteCount {
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return 1 + protocol.ByteCount(h.DestConnectionID.Len()) + protocol.ByteCount(h.PacketNumberLen)
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}
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// Log logs the Header
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func (h *ShortHeader) Log(logger utils.Logger) {
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logger.Debugf("\tShort Header{DestConnectionID: %s, PacketNumber: %d, PacketNumberLen: %d, KeyPhase: %s}", h.DestConnectionID, h.PacketNumber, h.PacketNumberLen, h.KeyPhase)
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}
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