Rust-Dagre

A high-performance Rust port of dagre.js, a directed graph layout library.

Based on

• dagre
• graphlib

Overview

This project uses napi-rs to provide a Universal Package supporting both Node.js Native Addons and WebAssembly (WASI).

Installation

yarn add @libnare/rust-dagre
# or
npm install @libnare/rust-dagre

Usage

Node.js

The package automatically loads the native binary for your platform. If the native binary is unavailable, it falls back to the WebAssembly (WASI) version.

Note: The layout function is asynchronous.

const { layout } = require('@libnare/rust-dagre');

async function run() {
  // 1. Define Nodes
  const nodes = JSON.stringify([
    { v: "1", width: 100, height: 50 },
    { v: "2", width: 100, height: 50 }
  ]);

  // 2. Define Edges
  const edges = JSON.stringify([
    { v: "1", w: "2" }
  ]);

  // 3. Optional Configuration
  const config = JSON.stringify({
    rankdir: "TB", // Top-to-Bottom
    align: "ul",   // Up-Left (ul, ur, dl, dr)
    nodesep: 50,
    ranksep: 50,
    edgesep: 10
  });

  // 4. Run Layout
  try {
    const result = await layout(nodes, edges, config);
    
    console.log("Graph Dimensions:", result.width, result.height);
    console.log("Nodes:", JSON.parse(result.nodesJson));
    console.log("Edges:", JSON.parse(result.edgesJson));
  } catch (err) {
    console.error("Layout failed:", err);
  }
}

run();

WebAssembly (Browser)

For browser usage, napi-rs handles the WASM loading. The usage is identical to Node.js, returning a Promise.

import { layout } from '@libnare/rust-dagre';

async function run() {
  // Define inputs (same as Node.js example)
  const nodes = JSON.stringify([
    { v: "1", width: 100, height: 50 },
    { v: "2", width: 100, height: 50 }
  ]);
  const edges = JSON.stringify([
    { v: "1", w: "2" }
  ]);

  // Usage is identical to Node.js
  const result = await layout(nodes, edges);
  console.log(result);
}

run();

API

layout(nodesJson, edgesJson, configJson?)

Computes the layout for the graph. Returns a Promise.

• nodesJson (string): JSON string array of nodes. Each node must have v (id), width, and height.

• edgesJson (string): JSON string array of edges. Each edge must have v (source) and w (target).

• configJson (string, optional): JSON string for layout configuration.

  • rankdir: "TB" | "BT" | "LR" | "RL" (default: "TB")
  • align: "ul" | "ur" | "dl" | "dr" (default: undefined)
  • nodesep: number (default: 50)
  • ranksep: number (default: 50)
  • edgesep: number (default: 20)
  • ranker: "network-simplex" | "tight-tree" | "longest-path" (default: "network-simplex")

• Returns: Promise<NapiLayoutResult> resolving to an object containing:

  • width: Total graph width.
  • height: Total graph height.
  • nodesJson: Updated nodes with x, y coordinates.
  • edgesJson: Updated edges with control points (points).

layoutSimple(inputJson)

A convenience function that takes a single JSON object containing nodes, edges, and config. Synchronous function.

• inputJson (string): { nodes: [...], edges: [...], layout: {...} }
• Returns: JSON string of the output { nodes, edges, width, height }.

Development

Prerequisites

• Rust: Stable toolchain (install via rustup).
• Node.js: v18+ recommended.
• Yarn: v4+ recommended.

Build Commands

1. Install Dependencies:

   yarn install

2. Build Native & WASM:

   yarn build

   This command builds the native addon for your current OS and the WASM target.

3. Run Tests:

   • JS Integration Tests:

     yarn test

4. Lint & Format:

   yarn lint
   yarn format

License

MIT