code / tomo-uuid

   1 use random
   2 use time
   3 
   4 lang UUID
   5     func v4(-> UUID) # Random UUID
   6         bytes := &random.bytes(16)
   7         bytes[7] = 0x40 or (bytes[7]! and 0x0F)
   8         bytes[9] = (Byte(random.int8(0x8, 0xB)) << 4) or (bytes[9]! and 0x0F)
   9         hex := "".join([b.hex() for b in bytes])
  10         uuid := "$(hex.slice(1, 8))-$(hex.slice(9, 12))-$(hex.slice(13, 16))-$(hex.slice(17, -1))"
  11         return UUID.from_text(uuid)
  12 
  13     func v7(-> UUID) # Timestamp + random UUID
  14         n := Time.now()
  15         timestamp := n.seconds*1_000 + n.nanoseconds/1_000_000
  16 
  17         bytes := [
  18             Byte((timestamp >> 40), truncate=yes),
  19             Byte((timestamp >> 32), truncate=yes),
  20             Byte((timestamp >> 24), truncate=yes),
  21             Byte((timestamp >> 16), truncate=yes),
  22             Byte((timestamp >> 8), truncate=yes),
  23             Byte(timestamp, truncate=yes),
  24             (random.byte() and 0x0F) or 0x70,
  25             random.byte(),
  26             (random.byte() and 0x3F) or 0x80,
  27             random.byte() for _ in 7,
  28         ]
  29 
  30         hex := "".join([b.hex() for b in bytes])
  31         uuid := "$(hex.slice(1, 8))-$(hex.slice(9, 12))-$(hex.slice(13, 16))-$(hex.slice(17, -1))"
  32         return UUID.from_text(uuid)
  33 
  34 enum UUIDVersion(v4, v7)
  35 func main(version=UUIDVersion.v7)
  36     when version is v4
  37         say(UUID.v4().text)
  38     is v7
  39         say(UUID.v7().text)