occurrence-sketch

High-performance Count-Min Sketch for tracking item frequencies with minimal memory.

Part of the Ocyrus suite.

✨ Features

• Fixed Memory: Track frequencies of millions of unique items using a pre-allocated Uint32Array.
• Probabilistic Counting: Provides estimates with a configurable error bound (epsilon) and certainty (delta).
• Zero-Allocation: Updates and lookups occur without creating temporary objects or arrays.
• Blazing Fast: $O(d)$ performance (where $d$ is the number of hash functions).

🚀 Performance

• count (lookup): ~5.0M ops/sec
• add (increment): ~2.3M ops/sec

📦 Installation

npm install @ocyrusjs/occurrence-sketch

🛠️ Usage

import { OccurrenceSketch } from '@ocyrusjs/occurrence-sketch';

// Create a sketch with 0.1% error bound and 99% certainty
const sketch = new OccurrenceSketch(0.001, 0.01);

sketch.add('page_view_home');
sketch.add('page_view_home');

// Estimates the count
console.log(sketch.count('page_view_home')); // 2

// Guaranteed to be >= true count
console.log(sketch.count('unknown_page')); // 0

License

MIT © Nishith Patel