Files
quic-go/protocol/version.go

56 lines
1.5 KiB
Go

package protocol
// VersionNumber is a version number as int
type VersionNumber int
// The version numbers, making grepping easier
const (
Version35 VersionNumber = 35 + iota
Version36
Version37
VersionWhatever = 0 // for when the version doesn't matter
VersionUnsupported = -1
)
// SupportedVersions lists the versions that the server supports
// must be in sorted descending order
var SupportedVersions = []VersionNumber{
Version37, Version36, Version35,
}
// VersionNumberToTag maps version numbers ('32') to tags ('Q032')
func VersionNumberToTag(vn VersionNumber) uint32 {
v := uint32(vn)
return 'Q' + ((v/100%10)+'0')<<8 + ((v/10%10)+'0')<<16 + ((v%10)+'0')<<24
}
// VersionTagToNumber is built from VersionNumberToTag in init()
func VersionTagToNumber(v uint32) VersionNumber {
return VersionNumber(((v>>8)&0xff-'0')*100 + ((v>>16)&0xff-'0')*10 + ((v>>24)&0xff - '0'))
}
// IsSupportedVersion returns true if the server supports this version
func IsSupportedVersion(supported []VersionNumber, v VersionNumber) bool {
for _, t := range supported {
if t == v {
return true
}
}
return false
}
// HighestSupportedVersion finds the highest version number that is both present in other and in SupportedVersions
// the versions in other do not need to be ordered
// it returns true and the version number, if there is one, otherwise false
func HighestSupportedVersion(other []VersionNumber) (bool, VersionNumber) {
for _, v := range SupportedVersions {
for _, ver := range other {
if ver == v {
return true, ver
}
}
}
return false, 0
}