Class ShortUniqueId

constructor

• new ShortUniqueId(argOptions?): ShortUniqueId

• Parameters

  • argOptions: Partial<ShortUniqueIdOptions> = {}

  Returns ShortUniqueId

counter

debug

dict

dictIndex

dictLength

dictRange

lowerBound

upperBound

uuidLength

version

approxMaxBeforeCollision

• approxMaxBeforeCollision(rounds?): number

• Calculates approximate number of hashes before first collision.

  Given that:

  • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()
  • the expected number of values we have to choose before finding the first collision can be expressed as the quantity Q(H)

  Then Q(H) can be approximated as the square root of the product of half of pi times H:

  

  This function returns Q(H).

  (see Poisson distribution)

  Parameters

  • rounds: number = ...

  Returns number

availableUUIDs

• availableUUIDs(uuidLength?): number

• Calculates total number of possible UUIDs.

  Given that:

  • H is the total number of possible UUIDs
  • n is the number of unique characters in the dictionary
  • l is the UUID length

  Then H is defined as n to the power of l:

  

  This function returns H.

  Parameters

  • uuidLength: number = ...

  Returns number

collisionProbability

• collisionProbability(rounds?, uuidLength?): number

• Calculates probability of generating duplicate UUIDs (a collision) in a given number of UUID generation rounds.

  Given that:

  • r is the maximum number of times that randomUUID() will be called, or better said the number of rounds
  • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()

  Then the probability of collision p(r; H) can be approximated as the result of dividing the square root of the product of half of pi times r by H:

  

  This function returns p(r; H).

  (see Poisson distribution)

  (Useful if you are wondering "If I use this lib and expect to perform at most r rounds of UUID generations, what is the probability that I will hit a duplicate UUID?".)

  Parameters

  • rounds: number = ...
  • uuidLength: number = ...

  Returns number

fmt

• fmt(format, date?): string

• Parameters

  • format: string
  • Optional date: Date

  Returns string

formattedUUID

• formattedUUID(format, date?): string

• Generates custom UUID with the provided format string.

  Parameters

  • format: string
  • Optional date: Date

  Returns string

  Alias

  const uid = new ShortUniqueId(); uid.fmt(format: string);

getVersion

• getVersion(): string

• Return the version of this module.

  Returns string

parseStamp

• parseStamp(suid, format?): Date

• Extracts the date embeded in a UUID generated using the uid.stamp(finalLength); method.

   const uidWithTimestamp = uid.stamp(32);
   console.log(uidWithTimestamp);
   // GDa608f973aRCHLXQYPTbKDbjDeVsSb3
  
   console.log(uid.parseStamp(uidWithTimestamp));
   // 2021-05-03T06:24:58.000Z
  Copy

  Parameters

  • suid: string
  • Optional format: string

  Returns Date

randomUUID

• randomUUID(uuidLength?): string

• Generates UUID by creating each part randomly.

  Parameters

  • uuidLength: number = ...

  Returns string

  Alias

  const uid = new ShortUniqueId(); uid.rnd(uuidLength: number);

rnd

• rnd(uuidLength?): string

• Parameters

  • uuidLength: number = ...

  Returns string

seq

• seq(): string

• Returns string

sequentialUUID

• sequentialUUID(): string

• Generates UUID based on internal counter that's incremented after each ID generation.

  Returns string

  Alias

  const uid = new ShortUniqueId(); uid.seq();

setCounter

• setCounter(counter): void

• Set the counter to a specific value.

  Parameters

  • counter: number

  Returns void

setDictionary

• setDictionary(dictionary, shuffle?): void

• Change the dictionary after initialization.

  Parameters

  • dictionary: string[] | ShortUniqueIdDefaultDictionaries
  • Optional shuffle: boolean

  Returns void

stamp

• stamp(finalLength, date?): string

• Generates a UUID with a timestamp that can be extracted using uid.parseStamp(stampString);.

   const uidWithTimestamp = uid.stamp(32);
   console.log(uidWithTimestamp);
   // GDa608f973aRCHLXQYPTbKDbjDeVsSb3
  
   console.log(uid.parseStamp(uidWithTimestamp));
   // 2021-05-03T06:24:58.000Z
  Copy

  Parameters

  • finalLength: number
  • Optional date: Date

  Returns string

uniqueness

• uniqueness(rounds?): number

• Calculate a "uniqueness" score (from 0 to 1) of UUIDs based on size of dictionary and chosen UUID length.

  Given that:

  • H is the total number of possible UUIDs, or in terms of this library, the result of running availableUUIDs()
  • Q(H) is the approximate number of hashes before first collision, or in terms of this library, the result of running approxMaxBeforeCollision()

  Then uniqueness can be expressed as the additive inverse of the probability of generating a "word" I had previously generated (a duplicate) at any given iteration up to the the total number of possible UUIDs expressed as the quotiend of Q(H) and H:

  

  (Useful if you need a value to rate the "quality" of the combination of given dictionary and UUID length. The closer to 1, higher the uniqueness and thus better the quality.)

  Parameters

  • rounds: number = ...

  Returns number

validate

• validate(uid, dictionary?): boolean

• Validate given UID contains only characters from the instanced dictionary or optionally provided dictionary.

  Parameters

  • uid: string
  • Optional dictionary: string[] | ShortUniqueIdDefaultDictionaries

  Returns boolean