Struct Rga 

pub struct Rga<T: Clone + Ord> { /* private fields */ }

A Replicated Growable Array (RGA) — an ordered sequence CRDT.

RGA supports insert and delete at arbitrary positions while guaranteeing convergence across replicas. Each element is assigned a unique identifier (actor, counter) which determines causal ordering.

Example

use crdt_kit::prelude::*;

let mut list1 = Rga::new(1);
list1.insert_at(0, 'H').unwrap();
list1.insert_at(1, 'i').unwrap();

let mut list2 = Rga::new(2);
list2.insert_at(0, '!').unwrap();

list1.merge(&list2);
list2.merge(&list1);

// Both replicas converge to the same sequence
let v1: Vec<&char> = list1.iter().collect();
let v2: Vec<&char> = list2.iter().collect();
assert_eq!(v1, v2);
assert_eq!(list1.len(), 3);

Implementations

impl<T: Clone + Ord> Rga<T>

pub fn new(actor: NodeId) -> Self

Create a new empty RGA for the given node.

pub fn fork(&self, new_actor: NodeId) -> Self

Create a fork of this replica with a different node ID.

pub fn insert_at(&mut self, index: usize, value: T) -> Result<(), RgaError>

Insert a value at the given index in the visible sequence.

pub fn remove(&mut self, index: usize) -> Result<T, RgaError>

Remove the element at the given index from the visible sequence.

pub fn get(&self, index: usize) -> Option<&T>

Get a reference to the element at the given index in the visible sequence.

pub fn len(&self) -> usize

Get the number of visible (non-tombstoned) elements.

pub fn is_empty(&self) -> bool

Check if the visible sequence is empty.

pub fn iter(&self) -> impl Iterator<Item = &T> + '_

Iterate over the visible elements in order.

pub fn actor(&self) -> NodeId

Get this replica’s node ID.

pub fn to_vec(&self) -> Vec<T>

Collect visible elements into a Vec.

Trait Implementations

impl<T: Clone + Clone + Ord> Clone for Rga<T>

fn clone(&self) -> Rga<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Clone + Ord> Crdt for Rga<T>

fn merge(&mut self, other: &Self)

Merge another replica’s state into this one.

impl<T: Debug + Clone + Ord> Debug for Rga<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: Clone + Ord> DeltaCrdt for Rga<T>

type Delta = RgaDelta<T>

The type of delta produced by this CRDT.

fn delta(&self, other: &Self) -> RgaDelta<T>

Generate a delta containing changes in self that other does not have.

fn apply_delta(&mut self, delta: &RgaDelta<T>)

Apply a delta to this replica’s state.

impl<T: PartialEq + Clone + Ord> PartialEq for Rga<T>

fn eq(&self, other: &Rga<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Clone + Ord> Versioned for Rga<T>

const CURRENT_VERSION: u8 = 1

Current schema version for this CRDT type’s serialization format.

const CRDT_TYPE: CrdtType = CrdtType::Rga

The CRDT type identifier for the envelope.

impl<T: Eq + Clone + Ord> Eq for Rga<T>

impl<T: Clone + Ord> StructuralPartialEq for Rga<T>