55 lines
1.7 KiB
Go
55 lines
1.7 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 VersionNumber = 0 // for when the version doesn't matter
|
|
VersionUnsupported VersionNumber = -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
|
|
}
|
|
|
|
// ChooseSupportedVersion finds the best version in the overlap of ours and theirs
|
|
// ours is a slice of versions that we support, sorted by our preference (descending)
|
|
// theirs is a slice of versions offered by the peer. The order does not matter
|
|
// if no suitable version is found, it returns VersionUnsupported
|
|
func ChooseSupportedVersion(ours, theirs []VersionNumber) VersionNumber {
|
|
for _, ourVer := range ours {
|
|
for _, theirVer := range theirs {
|
|
if ourVer == theirVer {
|
|
return ourVer
|
|
}
|
|
}
|
|
}
|
|
return VersionUnsupported
|
|
}
|