unique-id

Generates unique id

How does it work

Internally, it uses a pseudo-encrypt function based on a similar name from the Postgre Wiki. This encryption (not hashing) function generates a unique 32-bit signed integer from a given 32-bit integer. Since the function is an encryption, we can also infer that the pseudoEncrypt(pseudoEncrypt(x)) = x;.

Secondly, the resulting integer is used as a basis for generating a unique code. The integer is converted to the base-N sequence of characters constructed by the alphabet definition.

Users may define their own alphabet sequence, or their own sauce (a permutation formula being used inside pseudo-encrypt that produces a value between 0 and 1), to produce a completely different sequence of ids.

Usage

This package exports a default class named "UniqueIdGenerator". This class creates an instance for generating unique ids.

The constructor for UniqueIdGenerator may receive two parameters:

• alphabet - the base of character encryption. The default sequence is abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.
• sauce - a permutation formula used for the pseudo-encrypt algorithm. The default is ((1366 * r1 + 150889) % 714025) / 714025.0) where r1 is a 16-bit value.

Once an instance is constructed, the next method can be used to generate a unique string. This method receives a number that is used by the pseudo-encrypt function.

Reference

• Stack Overflow: https://stackoverflow.com/a/12590064