alexandrepiveteau/distributed-kotlin

WOOT and CRDTs for Kotlin

distributed-kotlin

This repository contains some utilies for distributed systems in the Kotlin programming language. The OSS license can be found in the LICENSE.md file of the repository.

Installation

This library is available on JitPack.io. Make sure to add the following Maven repository in your root build.gradle file :

allprojects {
	repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

You can now add the library modules in your application build.gradle file :

dependencies {
    implementation "com.github.alexandrepiveteau.distributed-kotlin:distributed-causal-graphs:1.1.0"
	implementation "com.github.alexandrepiveteau.distributed-kotlin:distributed-cvrdts:1.1.0"
	implementation "com.github.alexandrepiveteau.distributed-kotlin:distributed-woot:1.1.0"
}

Usage

The library contains the following modules :

• distributed-causal-graphs - An implementation of causal graphs, including CausalGraph<O, S> and CausalGraphYarn<O, S> with their mutable counterparts.
• distributed-cvrdts - An implementation of some popular CvRDTs, including GSet<T>, PNSet<T> and MCSet<T>.
• distributed-woot - An implementation of the Woot linear data structure.

distributed-cvrdts

The library offers multiple CvRDT data structures. Each data type is a state-based CRDT. Essentially, the GSet<T>, PNSet<T> and MCSet<T> classes all implement the Set<T> interface. Each of these data type is immutable, and multiple CRDTs of the same type can be merged by using their merge(...) function.

Here is an example of usage for the MCSet<T> data type :

var first: MCSet<String> = emptyMCSet()
var second: MCSet<String> = emptyMCSet()

first += "Alice"
first += "Bob"
first -= "Bob"
second += "Bob"
second += "Charlie"

val merged = first.merge(second) // Contains "Alice" and "Charlie".