suuid

short, sortable uuid. convert uuid into base 64 string along with coded timestamp.

Usage

<script src="<path-to>/suuid.bundle.min.js"></script>
<script>
  var id = suuid();
  var ts = suuid.timestamp(id);
  var short = suuid.encode("abc0123");
</script>

sample output ( try with test/gen.ls ):

generated suuid: OTeyNTN4r9fi49Wc5M.AsIMZT0NCe4
timestamp: 1611282605846 ( Fri Jan 22 2021 10:30:05 GMT+0800 (Taipei Standard Time) )

API

• suuid(opt): randomly return a suuid if opt is omitted. otherwise, opt can be:
  • a base16 string: return encoded corresponding string.
  • an object {id, timestamp}: return an encoded id prefix with timestamp, if timestamp is true.
    • id: a base16 string to encode.
    • timestamp: true if prefix timestamp before encoded id. default true.
• suuid.timestamp(id): get timestamp ( in epoch unix timestamp ) from given suuid
• suuid.encode(s): simply encode a base16 string to base64 string ( with our charmap, see below )

Spec

suuid does following things:

• prefix uuid(v4) with epoch unix timestamp

• remove separator ( dash ) in uuid.

• encodes values from hexadecimal to 64-based string with following charmap: ( url-safe chars according to the latest uri spec

  123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0_.

while length of codes corresponding to uuid part are fixed, length of the timestamp code varys. The timestamp bits will be:

• 7 bytes long before 2109AD
• 8 bytes long before 10895AD
• 9 bytes long before 573202AD

and the length of remaining part ( coded uuid, for randomness ) will be always 23 bytes long. thus, to sort suuid before 573202AD, simply add padding zeros before id to make it 32 bytes long.

Comparison

• uniqid

  • 18 bytes
  • no timestamp

• ulid

  • 48-bit timestamp + 80-bit entropy
  • base32 encoding, fixed length ( 26 character string. )
    • avoiding similar chars ( like 1IiJj ) and is case insensitive.
  • timestamped ( 1ms precision )
    • overflow after 10889AD

• ksuid

  • 32-bit timestamp + 128-bit entropy
  • base62 encoding ( 0-9a-zA-Z ), fixed length ( 27 characters string. )
  • timestamped ( 1s precision )
    • offset to start from 2014-03-05
    • overflow after 2150AD

• @plotdb/suuid

  • varied length timestamp ( 42-bit+ ) + 128-bit entropy
  • base64 encoding ( 0-9a-zA-Z.- ), varied length ( 30 characters + )
  • timestamped ( 1ms precision )
    • unix epoch timestamp ( since 1970-01-01 )

• uuid v6 proposal

  • TBD
  • try to add timestamp in uuid.
  • just a draft, and was expired.
  • Github Repo

License

MIT