Crate mdcs_merkle 

mdcs-merkle

Merkle-Clock DAG implementation for the MDCS (Merkle-Delta CRDT Store).

This crate provides:

• Content-addressed storage for causal history
• Merkle-DAG structure for verifiable, tamper-proof history
• DAGSyncer for gap-repair and synchronization
• Broadcaster for gossip-based head dissemination

Architecture

The Merkle-Clock serves as a logical clock that:

1. Provides verifiable causal ordering via hash-linked nodes
2. Enables gap-repair through content-addressed fetching
3. Supports open membership without metadata bloat
4. Handles concurrent updates via multi-root DAGs

Example

use mdcs_merkle::{MerkleNode, Payload, MemoryDAGStore, DAGStore, NodeBuilder};

// Create a DAG store
let mut store = MemoryDAGStore::new();

// Create the genesis node
let genesis = NodeBuilder::new()
    .with_payload(Payload::genesis())
    .build();
let genesis_cid = store.put(genesis).unwrap();

// Create a child node referencing the genesis
let child = NodeBuilder::new()
    .with_parents(vec![genesis_cid])
    .with_payload(Payload::delta(vec![1, 2, 3]))
    .build();
let child_cid = store.put(child).unwrap();

// The child is now a head
assert_eq!(store.heads(), vec![child_cid]);

Modules

broadcaster 🔒

Gossip-based broadcasting for head dissemination.

hash 🔒

Content-addressed hashing for Merkle nodes.

node 🔒

Merkle node definition and builder.

store 🔒

DAG storage trait and implementations.

syncer 🔒

DAG synchronization with gap-repair logic.

Structs

BroadcastConfig

Configuration for the broadcaster.

BroadcastMessage

A broadcast message containing head announcements.

BroadcastNetwork

Simulates a network of broadcasters for testing.

Broadcaster

Gossip-based broadcaster for head dissemination.

DAGSyncer

DAG synchronizer for gap-repair and reconciliation.

Hash

A 32-byte SHA-256 hash used as a Content Identifier (CID).

Hasher

Hasher utility for computing content hashes.

MemoryDAGStore

In-memory implementation of DAGStore.

MerkleNode

A node in the Merkle-DAG representing a causal event.

NodeBuilder

Builder for creating Merkle nodes.

SyncRequest

Request to fetch nodes from a peer.

SyncResponse

Response containing nodes from a peer.

SyncSimulator

Simulator for testing sync between multiple replicas.

Enums

DAGError

Errors that can occur during DAG operations.

Payload

The payload carried by a Merkle node.

SyncError

Errors that can occur during synchronization.

Traits

DAGStore

Trait for content-addressed DAG storage.