buid: universally unique lexicographically sortable identifiers
This package provides an implementation of flake ids that are lexicographically-sortable and highly unlikely to collide in a distributed system.
BUIDs can (and are meant to!) be safely stored inside a PostgreSQL UUID field.
1 Spec
A BUID is made up of a 40 bit time component and an 88 bit randomness component. The time component represents the current number of centiseconds since the UNIX timestamp 1586026830000.
BUIDs are represented as 22 character strings where the first 7 characters represent the 0-padded time component encoded in base 62 and the remaining 15 characters represent the 0-padded randomness component encoded in base 62.
The randomness component must have its most significant bit initially set to 0 and all ids generated within the same centisecond must increase monotonically.
In binary, BUIDs are represented as 16 bytes, encoded in network order.
2 Reference
value
procedure
(make-buid-factory) → (-> (and/c buid/c immutable?))
The generator functions are thread-safe.
procedure
(buid) → (-> (and/c buid/c immutable?))
> (require buid) > (for ([_ (in-range 10)]) (displayln (buid)))
0IAOWSU4hX0EmXa1EYlGiA
0IAOWSU4hX0EmXa1EYlGiB
0IAOWSU4hX0EmXa1EYlGiC
0IAOWSU4hX0EmXa1EYlGiD
0IAOWSU4hX0EmXa1EYlGiE
0IAOWSU4hX0EmXa1EYlGiF
0IAOWSU4hX0EmXa1EYlGiG
0IAOWSU4hX0EmXa1EYlGiH
0IAOWSU4hX0EmXa1EYlGiI
0IAOWSU4hX0EmXa1EYlGiJ
procedure
s : buid/c
procedure
s : buid/c
procedure
s : buid/c
procedure
(buid->bytes u) → buid-bytes/c
u : buid/c
procedure
(bytes->buid bs) → buid/c
bs : buid-bytes/c
procedure
(buid->uuid b) → string?
b : buid/c
Added in version 1.2 of package buid-lib.
procedure
(uuid->buid s) → buid/c
s : string?
Added in version 1.2 of package buid-lib.