MArrayCRDT - Movable Array Conflict-free Replicated Data Type

A CRDT implementation in Go that supports array operations including move, sort, reverse, and swap, with comprehensive benchmarking against leading CRDT libraries.

Repository Structure

├── crdt/                  # Core MArrayCRDT implementation (Go)
├── benchmarks/            # MArrayCRDT performance benchmarks (Go)
├── competitors/           # Competitor CRDT benchmarks (JavaScript)
│   ├── automerge/         # Automerge CRDT benchmarks
│   ├── yjs/               # Yjs CRDT benchmarks  
│   ├── loro/              # Loro CRDT benchmarks (Text + MovableList)
│   └── baseline/          # JavaScript Array baseline
├── web/                   # Interactive web visualization
├── data/                  # Benchmark data and editing traces
│   ├── paper.json         # Real editing trace (259k operations)
│   └── benchmark_runs/    # Timestamped benchmark results
└── run_all_benchmarks.sh  # Complete benchmark suite runner

Quick Start

Complete Benchmark Suite

# Run all benchmarks with proper isolation between libraries
./run_all_benchmarks.sh

This comprehensive suite:

• Runs MArrayCRDT (Go) with snapshot-based measurements
• Tests all JavaScript competitors with real memory tracking
• Uses 60-second cooldowns between runs for reliable measurements
• Generates timestamped results in data/benchmark_runs/
• Supports version comparison in the web UI

Individual Benchmarks

MArrayCRDT only:

cd benchmarks
go run marraycrdt_simulation.go

Specific competitor:

cd competitors/automerge
node --expose-gc simulation.js

Web Visualization

cd web
node server.js

Open http://localhost:3000 for interactive performance charts with:

• Real-time data loading from benchmark runs
• Version comparison between different benchmark sessions
• Memory usage and throughput visualization
• Operation count scaling analysis

Key Features

MArrayCRDT Capabilities

• Array Operations: Insert, delete, move, swap, sort, reverse, rotate
• Strong Consistency: Vector clock-based conflict resolution
• Move Support: Support for element repositioning

Benchmarking Framework

• Average Memory Tracking: Samples memory every 100 operations for stable measurements
• Process Isolation: 60-second cooldowns between competitor runs
• Academic Dataset: Uses real editing trace from Kleppmann et al. research

Competitor Analysis

• Automerge: Rich collaboration features with full operation history
• Yjs: High-performance text editing optimization
• Loro: Text CRDT with optional MovableList (comparable to MArrayCRDT)
• Baseline: Plain JavaScript Array for overhead comparison

Architecture

Memory Management

• Go advantages: Predictable memory layout, efficient GC, direct struct control
• JavaScript overhead: Object wrapping, prototype chains, V8 runtime costs
• Real measurements: Average memory sampling during execution, not endpoint diffs

CRDT Design

• Element-level tracking: Each array element has unique ID, vector clock, position metadata
• Position-based ordering: Floating-point positions enable efficient move operations
• Conflict resolution: Last-Writer-Wins with deterministic tiebreaking
• Operation support: Beyond text editing - full array manipulation capabilities