com.brunobonacci.mulog.flakes — com.brunobonacci/mulog 0.9.0

Flakes are like snowflakes, no two are the same.

This is an implementation of a 192-bits unique ids which has the following characteristics:

• Monotonic IDs Every new ID is larger than the previous one. The idea is that the 'happens before' relationship applies to these IDs. If you observe a Flake and you create a new one in the same thread, the new Flake is going to be larger than the previous one. There is no synchronisation and it uses a wall clock as well as a monotonic clock as part of the generation, therefore Flakes created across processes/machines might suffer from clock skew and hard reset. Generally the following condition should apply for all Flakes flake0 < flake1 < flake2 < ... < flakeN

• Two components: one time-based (64 bits), one random (128 bits) The most significant bits are time based and they use a monotonic clock with nanosecond resolution. The next 128 bits are randomly generated.

• Random-based The Random component is built with a PRNG for speed. It uses 128 full bits, more bits than java.util.UUID/randomUUID which has 6 bits reserved for versioning and type, therefore effectively only using 122 bits.

• Homomorphic representation Whether you choose to have a bytes representation or string representation it uses an encoding which maintain the ordering. Which it means that: if flake1 < flake2 then flake1.toString() < flake2.toString() Internally it uses a NON STANDARD base64 encoding to preserve the ordering. Unfortunately, the standard Base64 encoding doesn't preserve this property as defined in https://en.wikipedia.org/wiki/Base64.

• Web-safe string representation. The string representation uses only characters which are web-safe and can be put in a URL without the need of URL encoding.

• Fast, speed is important so we target under 50 nanosecond for 1 id. These are the performances measured with Java 1.8.0_232 for the creation of a new Flake.

  Evaluation count : 1570017720 in 60 samples of 26166962 calls.
  Execution time mean : 36.429623 ns
  Execution time std-deviation : 0.519843 ns
  Execution time lower quantile : 35.684111 ns ( 2.5%)
  Execution time upper quantile : 37.706974 ns (97.5%)
  Overhead used : 2.090673 ns
  
  Found 4 outliers in 60 samples (6.6667 %)
  low-severe 4 (6.6667 %)
  Variance from outliers : 1.6389 % Variance is slightly inflated by outliers
  

  These are the performances for creating an new Flake and turn it into a string

  Evaluation count : 755435400 in 60 samples of 12590590 calls.
  Execution time mean : 78.861983 ns
  Execution time std-deviation : 1.006261 ns
  Execution time lower quantile : 77.402593 ns ( 2.5%)
  Execution time upper quantile : 81.006901 ns (97.5%)
  Overhead used : 1.881732 ns
  

flake clj

(flake)

A time-ordered, pseudo-random, Universal ID of 192 bits

flake-hex clj

(flake-hex flake)

Hexadecimal representation

flake-time clj

(flake-time flake)

Returns the timestamp in nanoseconds

flake? clj

(flake? f)

returns true if f is an instance of a Flake.

read-method clj

(read-method flake)

Reader method

snowflake clj

(snowflake)

A time-ordered, pseudo-random, Universal ID of 192 bits represented as a 32bytes strings