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)))
0I4kJl22XhwI622XsA7rwU
0I4kJl22XhwI622XsA7rwV
0I4kJl22XhwI622XsA7rwW
0I4kJl22XhwI622XsA7rwX
0I4kJl22XhwI622XsA7rwY
0I4kJl22XhwI622XsA7rwZ
0I4kJl22XhwI622XsA7rwa
0I4kJl22XhwI622XsA7rwb
0I4kJl22XhwI622XsA7rwc
0I4kJl22XhwI622XsA7rwd
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.