diff options
Diffstat (limited to 'vendor/github.com/google/uuid/version7.go')
| -rw-r--r-- | vendor/github.com/google/uuid/version7.go | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/vendor/github.com/google/uuid/version7.go b/vendor/github.com/google/uuid/version7.go index ba9dd5eb6..3167b643d 100644 --- a/vendor/github.com/google/uuid/version7.go +++ b/vendor/github.com/google/uuid/version7.go @@ -44,7 +44,7 @@ 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 +// see function NewV7 and NewV7FromReader func makeV7(uuid []byte) { /* 0 1 2 3 @@ -52,7 +52,7 @@ func makeV7(uuid []byte) { +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | unix_ts_ms | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | unix_ts_ms | ver | rand_a | + | unix_ts_ms | ver | rand_a (12 bit seq) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |var| rand_b | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ @@ -61,7 +61,7 @@ func makeV7(uuid []byte) { */ _ = uuid[15] // bounds check - t := timeNow().UnixMilli() + t, s := getV7Time() uuid[0] = byte(t >> 40) uuid[1] = byte(t >> 32) @@ -70,6 +70,35 @@ func makeV7(uuid []byte) { uuid[4] = byte(t >> 8) uuid[5] = byte(t) - uuid[6] = 0x70 | (uuid[6] & 0x0F) - // uuid[8] has already has right version + uuid[6] = 0x70 | (0x0F & byte(s>>8)) + uuid[7] = byte(s) +} + +// lastV7time is the last time we returned stored as: +// +// 52 bits of time in milliseconds since epoch +// 12 bits of (fractional nanoseconds) >> 8 +var lastV7time int64 + +const nanoPerMilli = 1000000 + +// 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) { + timeMu.Lock() + defer timeMu.Unlock() + + nano := timeNow().UnixNano() + milli = nano / nanoPerMilli + // Sequence number is between 0 and 3906 (nanoPerMilli>>8) + seq = (nano - milli*nanoPerMilli) >> 8 + now := milli<<12 + seq + if now <= lastV7time { + now = lastV7time + 1 + milli = now >> 12 + seq = now & 0xfff + } + lastV7time = now + return milli, seq } |