What is the [random:hash:?] token?

Question

I created a marketplace with two fields: a "Store Reference" field that the store owner fills, a "SKU" field I want to be unique and generated automatically.

On Drupal Commerce I want the SKU of my products to be generated automatically and made unique.

I want a sequence of numbers and random letters, for example a single SKU of 12 characters (number and letter).

There is a hash token in "Explore Available Tokens" and "Random". What is it used for?
Can it meet my needs?
Can it generate a unique code that will never be reused?

There are several store owners who can create products at the same time; the same SKU must not be generated.

Answer 1

It's a token for generating a random string. When you look into the implementation, you can see it's the result of hashing 55 random bytes with your selected hashing algorithm (the ? part of random:hash:?).

Will it meet your uniqueness needs? Yes.

Since we're talking pseudo-randomness here and the fact that hashing algorithms can produce collisions, there's a possibility of the same string being generated but it's very unlikely (unless you have a massive number of SKUs being generated).

In the unlikely event that Commerce & the AutoSKU don't have the logic to prevent SKU collision (which should be there as its a unique attribute), you can always add more patterns in the token (e.g. UID) to lessen the collision possibility to effectively zero, for the number of SKUs needed by your store.