Diamond Types Extended

High-performance CRDTs (Conflict-free Replicated Data Types) for collaborative applications.

Diamond Types Extended is a fork of diamond-types with extended types and a unified API.

Features

• Map - Key-value container with LWW (Last-Writer-Wins) registers per key
• Text - Sequence CRDT for collaborative text editing
• Set - OR-Set (Observed-Remove) with add-wins semantics
• Register - Single-value LWW container
• Nesting - All types can be nested within Maps
• Replication - Efficient sync between peers

Quick Start

use diamond_types_extended::{Document, Value};

// Create a document
let mut doc = Document::new();
let alice = doc.get_or_create_agent("alice");

// All mutations happen in transactions
doc.transact(alice, |tx| {
    tx.root().set("title", "My Document");
    tx.root().set("count", 42);
    tx.root().create_text("content");
});

// Work with nested text
doc.transact(alice, |tx| {
    if let Some(mut text) = tx.get_text_mut(&["content"]) {
        text.insert(0, "Hello, world!");
    }
});

// Read values directly
assert_eq!(doc.root().get("title").unwrap().as_str(), Some("My Document"));
assert_eq!(doc.root().get_text("content").unwrap().content(), "Hello, world!");

Replication

use diamond_types_extended::{Document, Frontier};

let mut doc_a = Document::new();
let mut doc_b = Document::new();

let alice = doc_a.get_or_create_agent("alice");
let bob = doc_b.get_or_create_agent("bob");

// Alice makes changes
doc_a.transact(alice, |tx| {
    tx.root().set("from_alice", "hello!");
});

// Sync to Bob
let ops = doc_a.ops_since(&Frontier::root()).into_owned();
doc_b.merge_ops(ops).unwrap();

// Bob now has Alice's changes
assert!(doc_b.root().contains_key("from_alice"));

Conflict Resolution

Diamond Types Extended uses deterministic conflict resolution:

• Maps: LWW (Last-Writer-Wins) based on (lamport_timestamp, agent_id) ordering
• Sets: Add-wins semantics (concurrent add + remove = add wins)
• Text: Interleaving based on operation ordering

You can detect and handle conflicts explicitly:

let conflicted = doc.root().get_conflicted("key").unwrap();
if conflicted.has_conflicts() {
    println!("Winner: {:?}", conflicted.value);
    println!("Losers: {:?}", conflicted.conflicts);
}

Performance

Diamond Types Extended inherits diamond-types' exceptional performance:

• Run-length encoded operation storage
• Optimized causal graph tracking
• The "egwalker" merge algorithm

See the original diamond-types blog post for benchmarks.

Attribution

Diamond Types Extended is built on diamond-types by Joseph Gentle (@josephg).

See ATTRIBUTION.md for full credits.

License

ISC License - see LICENSE for details.