URL Shortener

Technologies

• Next JS
• TypeScript
• MySQL
• Prisma
• Zod
• Tailwind CSS

Run Locally

Clone the project

  git clone https://github.com/asif-jalil/url-shortener.git

Go to the project directory

  cd url-shortener

Install dependencies

  npm install

Copy .env.example to .env and fill credential

Generate prisma instance

  npx prisma generate

Prepare database

 npm run db:baseline

Start the server

  npm run dev

How to

• Build for production : npm run build:prod
• Run production : npm start
• Check linting: npm run lint
• Formatting: npm run format
• Type checking: npm run typecheck

Summary: Unique ID Generation and Uniqueness

Key Features of the getUniqueId Function

1. Custom Alphabet: Uses a 64-character urlAlphabet (Base64-like) for ID generation.
2. Cryptographic Randomness: Ensures robust randomness via crypto.getRandomValues, making IDs hard to predict and secure.
3. Random Byte Pool: Optimizes performance by reusing a prefilled pool of random bytes, reducing overhead for frequent ID generation.

Uniqueness Analysis

• Total Possible IDs:

  • Size 6 (Default): 64^6 = 68.7 billion unique IDs.

• Collision Probability:

  • For 𝑁 = 68.7 billion (size 6):
    • Generating 1 million IDs: ~0.73% chance of collision.
    • Generating 10 million IDs: ~71.7% chance of collision.

• Practical Implications:

  • Size 6: Suitable for small systems generating up to a few hundred thousand IDs.
  • Size 8: Ideal for large-scale systems with negligible collision probability.

• Handling Collisions:

  • In critical systems, ensure uniqueness by checking generated IDs in a database or combining random IDs with timestamps or contextual data.