A UUID wrapper that has a base64 display and serialization
A newtype around UUIDs that:
- Displays and Serializes as Base64
- Specifically it is the url-safe base64 variant, with no padding
let known_id = Uuid::parse_str("b0c1ee86-6f46-4f1b-8d8b-7849e75dbcee").unwrap(); let as_b64 = UuidB64::from(known_id); assert_eq!(as_b64.to_string(), "sMHuhm9GTxuNi3hJ51287g"); let parsed_b64: UuidB64 = "sMHuhm9GTxuNi3hJ51287g".parse().unwrap(); assert_eq!(parsed_b64, as_b64); let raw_id = Uuid::new_v4(); assert_eq!(raw_id.to_string().len(), 36); let uuidb64 = UuidB64::from(raw_id); assert_eq!(uuidb64.to_string().len(), 22);
UuidB64::new creates v4 UUIDs, because... that's what I use. I'm open to
hearing arguments about why this is a ridiculous decision and I should have
UUIDs are great:
- They have a known size and representation, meaning that they are well-supported with an efficient representation in a wide variety of systems. Things like programming languages and databases.
- V4 (almost completely random) UUIDs have nice sharding properties, you can give out UUIDs willy-nilly without coordination and still be guaranteed to not have a conflict of IDs between two items across systems.
That said, the standard representation for UUIDs is kind of annoying:
- It's a long: 36 characters to represent 16 bytes of data!
- It's hard to read: it is only hexadecimal characters. The human eye needs to pay a lot of attention to be certain if any two UUIDs are the same.
I guess that's it. Base64 is a more human-friendly representation of UUIDs:
- It's slightly shorter: 1.375 times the size of the raw data (22 characters), vs 2.25 times the size characters.
- Since it is case-sensitive, the shape of the IDs helps to distinguish between different IDs. There is also more entropy per character, so scanning to find a difference is faster.
That said, there are drawbacks to something like this:
If you store it as a UUID column in a database IDs won't show up in the same way as it does in your application code, meaning you'll (A) maybe want to define a new database type, or B just expect to only ever interact with the DB via you application.
Conversion functions are pretty trivial, this works in postgres (inefficiently, but it's only for interactive queries so whatever):
CREATE FUNCTION b64uuid(encoded TEXT) RETURNS UUID AS $$ BEGIN RETURN ENCODE(DECODE(REPLACE(REPLACE( encoded, '-', '+'), '_', '/') || '==', 'base64'), 'hex')::UUID; END $$ LANGUAGE plpgsql;
UuidB64 everywhere you would use
Uuid, and use
to create one from an existing UUID.
serdeenables serialization/deserialization via Serde.
diesel-uuidenables integration with Diesel's UUID support, this is only tested on postgres, PRs welcome for other DBs.
It's a Uuid that displays as Base 64