77 lines
1.8 KiB
Go
77 lines
1.8 KiB
Go
package protocol
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// StreamType encodes if this is a unidirectional or bidirectional stream
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type StreamType uint8
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const (
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// StreamTypeUni is a unidirectional stream
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StreamTypeUni StreamType = iota
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// StreamTypeBidi is a bidirectional stream
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StreamTypeBidi
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)
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// InvalidPacketNumber is a stream ID that is invalid.
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// The first valid stream ID in QUIC is 0.
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const InvalidStreamID StreamID = -1
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// StreamNum is the stream number
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type StreamNum int64
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const (
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// InvalidStreamNum is an invalid stream number.
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InvalidStreamNum = -1
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// MaxStreamCount is the maximum stream count value that can be sent in MAX_STREAMS frames
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// and as the stream count in the transport parameters
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MaxStreamCount StreamNum = 1 << 60
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)
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// StreamID calculates the stream ID.
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func (s StreamNum) StreamID(stype StreamType, pers Perspective) StreamID {
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if s == 0 {
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return InvalidStreamID
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}
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var first StreamID
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switch stype {
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case StreamTypeBidi:
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switch pers {
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case PerspectiveClient:
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first = 0
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case PerspectiveServer:
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first = 1
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}
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case StreamTypeUni:
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switch pers {
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case PerspectiveClient:
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first = 2
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case PerspectiveServer:
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first = 3
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}
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}
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return first + 4*StreamID(s-1)
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}
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// A StreamID in QUIC
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type StreamID int64
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// InitiatedBy says if the stream was initiated by the client or by the server
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func (s StreamID) InitiatedBy() Perspective {
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if s%2 == 0 {
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return PerspectiveClient
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}
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return PerspectiveServer
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}
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// Type says if this is a unidirectional or bidirectional stream
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func (s StreamID) Type() StreamType {
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if s%4 >= 2 {
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return StreamTypeUni
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}
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return StreamTypeBidi
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}
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// StreamNum returns how many streams in total are below this
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// Example: for stream 9 it returns 3 (i.e. streams 1, 5 and 9)
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func (s StreamID) StreamNum() StreamNum {
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return StreamNum(s/4) + 1
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}
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