darn_core

Core library for darn - CRDT-backed filesystem management.

Overview

darn_core provides the foundational types and logic for managing files as Automerge CRDT documents. It handles:

• Workspace management - .darn/ directory structure
• File ↔ document mapping - Converting files to/from Automerge documents
• Manifest tracking - Mapping file paths to Sedimentree IDs
• Change detection - BLAKE3 content hashing for efficient diffing
• Ignore patterns - .darnignore support (gitignore syntax)

Architecture

┌──────────────────────────────────────────────────────────┐
│                        darn_core                         │
├──────────────────────────────────────────────────────────┤
│  workspace.rs   │ .darn/ directory management            │
│  file.rs        │ File ↔ Automerge conversion            │
│  manifest.rs    │ Tracked, ContentHash, FileState        │
│  refresh.rs     │ Change detection & incremental commits │
│  signer.rs      │ Ed25519 key management                 │
│  config.rs      │ Global config (~/.config/darn/)        │
│  ignore.rs      │ .darnignore pattern matching           │
└──────────────────────────────────────────────────────────┘

Key Types

File

Patchwork-compatible file representation:

use darn_core::file::{File, content::Content};

// Create from file
let doc = File::from_path("example.txt")?;

// Or construct directly
let doc = File::text("notes.txt", "Hello, world!");

// Convert to Automerge
let mut am_doc = doc.to_automerge()?;
let bytes = am_doc.save();

Workspace

Manages the .darn/ directory:

use darn_core::workspace::Workspace;

// Initialize new workspace
let ws = Workspace::init(".")?;

// Open existing
let ws = Workspace::open(".")?;

// Access components
let manifest = ws.load_manifest()?;
let storage = ws.storage()?;
let peer_id = ws.peer_id()?;

Tracked & FileState

Track files with change detection:

use darn_core::manifest::{Tracked, FileState, ContentHash};

// Check file state
match entry.state(workspace_root) {
    FileState::Clean => println!("unchanged"),
    FileState::Modified => println!("changed on disk"),
    FileState::Missing => println!("deleted"),
}

File Document Schema

Patchwork-inspired schema:

Content encoding:

• Text files → Text object (character-level CRDT merging)
• Binary files → Bytes scalar (last-writer-wins)

Serialization

File documents use Automerge's direct API rather than serde integration. This gives explicit control over CRDT types (e.g., ObjType::Text for character-level merging vs ScalarValue::Bytes for LWW semantics).

Dependencies

License

Apache-2.0 OR MIT