rn-compute-bench

CPU performance benchmarking library for React Native with MD5 brute-force implementations in JavaScript, Rust, and Kotlin.

Overview

rn-compute-bench is a React Native library that enables developers to benchmark CPU-intensive operations across three different execution environments:

• JavaScript (React Native) - Pure JS implementation running in the JS engine
• Rust (TurboModules + FFI) - Native high-performance implementation via TurboModules and Rust FFI
• Kotlin (Native Android) - Native Android implementation with coroutines

Perfect for profiling device performance, comparing native vs JS execution, and testing CPU-bound workloads in production apps.

Features

• Type-Safe API - Full TypeScript support with detailed types
• Production Ready - Optimized implementations with cancellation support
• Example App Included - Full-featured benchmark UI

Installation

npm install rn-compute-bench
# or
yarn add rn-compute-bench

Requirements

• React Native 0.76+ with New Architecture enabled
• Android: API Level 21+
• iOS: iOS 13+

Usage

Basic Example

import {
  MD5BruteForceRust,
  MD5BruteForceKotlin,
  MD5BruteForceJS,
  type BruteForceResult,
} from 'rn-compute-bench';

// Using Rust implementation (fastest)
const result = await MD5BruteForceRust.bruteForceHash(
  '5d41402abc4b2a76b9719d911017c592', // MD5 hash of "hello"
  5 // max length to test
);

console.log(result);
// {
//   found: true,
//   plaintext: 'hello',
//   attempts: 123456,
//   timeMs: 45.2,
//   checksPerSecond: 2730000
// }

// Using Kotlin implementation (Android only)
const kotlinResult = await MD5BruteForceKotlin.bruteForceHash(
  '0cc175b9c0f1b6a831c399e269772661', // MD5 hash of "a"
  3
);

// Using JavaScript implementation (cross-platform)
const jsResult = await MD5BruteForceJS.bruteForceHash(
  'e4da3b7fbbce2345d7772b0674a318d5', // MD5 hash of "5"
  2,
  {
    onProgress: (attempts, current, checksPerSecond) => {
      console.log(`Tested: ${current}, Speed: ${checksPerSecond.toFixed(0)} checks/sec`);
    },
    shouldCancel: () => userRequestedCancel,
  }
);

Generating MD5 Hashes

// Rust
const hash = MD5BruteForceRust.generateMd5('hello');
// "5d41402abc4b2a76b9719d911017c592"

// Kotlin (Android only)
const hash = await MD5BruteForceKotlin.generateMd5('hello');

// JavaScript
const hash = MD5BruteForceJS.generateMd5('hello');

Cancellation

// Start brute force
const promise = MD5BruteForceRust.bruteForceHash(hash, 10);

// Cancel from another part of your code
MD5BruteForceRust.cancelBruteForce();

// JavaScript cancellation via callback
let shouldStop = false;
const jsPromise = MD5BruteForceJS.bruteForceHash(hash, 10, {
  shouldCancel: () => shouldStop,
});

// Later...
shouldStop = true;

API Reference

MD5BruteForceRust

High-performance Rust implementation

Methods

• bruteForceHash(targetHash: string, maxLength: number): Promise<BruteForceResult>

  Attempts to crack an MD5 hash by testing combinations up to maxLength characters.

• cancelBruteForce(): void

  Cancels the ongoing brute force operation.

• generateMd5(input: string): string

  Generates an MD5 hash from the input string.

MD5BruteForceKotlin (Android only)

Native Kotlin implementation with coroutines.

Methods

Same as MD5BruteForceRust but:

• generateMd5(input: string): Promise<string> - Returns a promise

Note: Only available on Android.

MD5BruteForceJS

Pure JavaScript implementation with progress callbacks.

Methods

• bruteForceHash(targetHash: string, maxLength: number, callbacks?: BruteForceCallbacks): Promise<BruteForceResult>

  JavaScript implementation with optional progress tracking.

  interface BruteForceCallbacks {
    onProgress?: (attempts: number, current: string, checksPerSecond: number) => void;
    shouldCancel?: () => boolean;
  }

• generateMd5(input: string): string

Types

interface BruteForceResult {
  found: boolean;
  plaintext: string;
  attempts: number;
  timeMs: number;
  checksPerSecond: number;
}

Character Set: 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ (62 characters)

Example App

Screenshots

Performance Comparison (cracking "deal" hash - 4 characters, 3,394,956 attempts):

• JavaScript: 131.84s @ 25,751 checks/sec
• Kotlin: 4.88s @ 695,973 checks/sec (27x faster)
• Rust: 2.09s @ 1,626,009 checks/sec (63x faster)

Try the Pre-built Android APK

Don't want to build from source? Download and install the pre-built benchmark app:

Download APK

Requirements: Android 6.0 (API 23) or higher

See the releases folder for more details.

Build from Source

Alternatively, build and run the example app yourself:

# Clone the repository
git clone https://github.com/iNerdstack/rn-compute-bench.git
cd rn-compute-bench

# Install dependencies
yarn install
cd example && yarn install && cd ..

# Run on Android
cd example && yarn android

The example app includes:

• Interactive hash input with presets
• Mode selector (JS/Rust/Kotlin)
• Real-time performance metrics
• Visual results comparison
• Example test hashes

Use Cases

• Device Profiling: Measure CPU performance across different device models
• Performance Testing: Benchmark native vs JavaScript performance
• Load Testing: Test app behavior under CPU-intensive operations
• Cross-Platform Comparison: Compare iOS (Rust) vs Android (Rust/Kotlin) performance
• Educational: Learn about native module integration and performance optimization

Development

Building from Source

If you want to modify the native implementations:

# Prerequisites
# - Rust 1.82+ (https://rustup.rs/)
# - Android NDK (set ANDROID_NDK_HOME)

# Install dependencies
yarn install

# Generate TurboModule bindings (using Craby)
npx crabygen

# Build native modules
npx crabygen build

# Test changes
cd example && yarn android

Project Structure

rn-compute-bench/
├── src/                          # TypeScript module exports
│   ├── index.ts                  # Main exports
│   ├── NativeBruteForceRust.ts   # Rust module spec
│   ├── BruteForceKotlin.ts       # Kotlin module interface
│   └── MD5BruteForceJS.ts        # JS implementation
├── crates/                       # Rust implementation
│   └── lib/src/
│       └── brute_force_rust_impl.rs
├── android/                      # Android native module
│   └── src/main/java/com/rncomputebench/
│       └── NativeBruteForceKotlinModule.kt
├── cpp/                          # C++ bridging (auto-generated)
└── example/                      # Example React Native app
    └── src/
        └── screens/BenchmarkScreen.tsx

Contributing

Contributions are welcome! Ideas for improvements:

• Implement parallel processing optimizations
• Add performance visualization graphs
• Create benchmarking presets for common operations

License

MIT License - See LICENSE file for details.

Author

Nerd Stack

• Email: [email protected]
• GitHub: @iNerdstack

Note: This library is designed for performance testing and educational purposes.