// UUID version 7 features a time-ordered value field derived from the widely // implemented and well known Unix Epoch timestamp source, // the number of milliseconds seconds since midnight 1 Jan 1970 UTC, leap seconds excluded. // As well as improved entropy characteristics over versions 1 or 6. // // see https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-03#name-uuid-version-7 // // Implementations SHOULD utilize UUID version 7 over UUID version 1 and 6 if possible. // // NewV7 returns a Version 7 UUID based on the current time(Unix Epoch). // Uses the randomness pool if it was enabled with EnableRandPool. // On error, NewV7 returns Nil and an error func NewV7() (UUID, error) { … } // NewV7FromReader returns a Version 7 UUID based on the current time(Unix Epoch). // it use NewRandomFromReader fill random bits. // On error, NewV7FromReader returns Nil and an error. func NewV7FromReader(r io.Reader) (UUID, error) { … } // makeV7 fill 48 bits time (uuid[0] - uuid[5]), set version b0111 (uuid[6]) // uuid[8] already has the right version number (Variant is 10) // see function NewV7 and NewV7FromReader func makeV7(uuid []byte) { … } var lastV7time … const nanoPerMilli … // getV7Time returns the time in milliseconds and nanoseconds / 256. // The returned (milli << 12 + seq) is guarenteed to be greater than // (milli << 12 + seq) returned by any previous call to getV7Time. func getV7Time() (milli, seq int64) { … }