Uuid: short uuid

[ORESoftware]

I am willing to take a greater risk of collisions for a shorter uuid.

right now I have this:

"file:///home/node/.docker_r2g_cache/83cd49f2-45ba-49ec-9b72-6f84a8adeec7/residence"

I am looking for something more like:

"file:///home/node/.docker_r2g_cache/6f84a8adeec7/residence"

can this library do that or should I use another lib? any recommendations? thx

[garthk]

The shorter you make your nonce, the more likely you are to run into collisions. If you know how many unique keys you need, you can calculate the odds: look up “Birthday Paradox”. If you’re OK with the odds, it’s easiest to take a slice of the last ten hex digits of a v4. If you need more bits, take care to not use the bits that indicate which kind of UUID you have: those aren’t random.

[broofa]

I'd suggest using another lib. This lib is specifically for creating RFC4122 UUIDs, which have a specific syntax. If all you care about is length of id, then you'll want one that draws from a larger set of chars than the 16 hex digits.

Something like https://www.npmjs.com/package/shortid, perhaps? A 21-char id from that lib should have roughly the same chance of collision as the 36-char v4 UUID from this lib.

[ORESoftware]

thanks all, I asked this question on shortid:
https://github.com/dylang/shortid/issues/119

I currently am using the 8 char id, which I calculate 2 given ids as having about 1 in 4trillion chance of colliding.

[broofa]

Careful. The odds of collision increase dramatically as you generate more ids. Commented on that shortid issue with details.

[ORESoftware]

@broofa yeah I am not generating that many ids, less than 20 that can collide at any time, never more than 20 different ids that could collide with one another. that's why I am willing to risk collision, because the niceness/readability of short ids is useful for users.