LWW-Element-Set with SwiftUI

Overview

This repository contains an example implementation of a Last-Write-Wins Element Set (LWW-Element-Set) in Swift, integrated with a SwiftUI interface for basic simulations.

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Features

• LWW-Element-Set CRDT: Implemented in Swift
• SwiftUI Interface: For basic element addition and removal simulations for two users
• Timestamp-Based Conflict Resolution
• Element List View: Showing elements added by each user with timestamp

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Getting Started

Prerequisites

• Swift 5.0 or later
• Xcode 12.0 or later

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Installation

1. Clone the Repository

   git clone https://github.com/ronstorm/LWWElementSet.git

2. Open the Project in Xcode

3. Build and Run the project on a simulator or real device

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Usage

Basic Usage

• To Add an Element to the LWW-Element-Set for a particular user:

  let element = ElementWithUser(element: "Example", user: "UserA")
  let timestamp = Timestamp(replicaID: "UserA", counter: 1)
  elementSet.add(element: element, timestamp: timestamp)

• To Remove an Element:

  elementSet.remove(element: element, timestamp: newerTimestamp)

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Simulation

• In the SwiftUI interface, you can start and stop timers for two users (User A and User B). Each timer simulates adding random elements to the LWW-Element-Set.

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Viewing Added Elements

• You can view the added elements in a SwiftUI List. Each element is tagged with the user who added it and the timestamp.

  List(elements, id: \.self) { element in
      Text("\(element.element) (\(element.user))")
  }

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Conflict Resolution

• The LWW-Element-Set implementation in this project handles conflict resolution based on timestamps, ensuring that the last-written element wins.

  if addSet[element]! > removeSet[element]! {
      // Element is considered to be in the set
  }

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License

• This project is licensed under the MIT License.

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Contributing

• For contributions, please open an issue first to discuss what you would like to change.