# Performance and Optimization

The focus of **eQuantic.UI** is to deliver a Single Page Application (SPA) experience with minimal overhead, leveraging the power of C# to generate highly optimized frontend code.

## 🚀 Reconciliation and Virtual DOM

The Virtual DOM system was designed to be efficient and anticipate state changes.

### Diffing Strategy (Keyed LIS Algorithm)

The reconciliation algorithm uses an efficient **Keyed Diffing** strategy based on the **Longest Increasing Subsequence (LIS)** algorithm.

- **Key Property**: The `key` property identifies elements across renders. Elements with the same key are reused and updated in place.
- **LIS Optimization**: When elements are reordered, the algorithm computes the longest increasing subsequence to minimize DOM movements. Only elements outside the LIS need to be moved.
- **Prefix/Suffix Optimization**: Common prefixes and suffixes are processed first without complex diffing, improving performance for typical list operations (append, prepend).
- **Memory Efficiency**: Unmoved elements preserve their browser state (input focus, scroll position, etc.).

## 🧠 Resource Management (Memory Management)

Memory leaks are mitigated through the intelligent use of weak references and automatic cleanup.

### Event Listener Tracking

Event listeners are tracked using `WeakMap<HTMLElement, Map<string, EventHandler>>`.

- **Weak References**: `WeakMap` allows DOM elements to be collected by the Garbage Collector when removed from the tree, even if the framework still has internal references to their handlers.
- **Automatic Cleanup**: When removing a component, the reconciler attempts to explicitly disconnect listeners, but the `WeakMap` acts as a safety net to prevent leaks in complex lifecycles.

## 📦 Bundling and Loading

### Hybrid Strategy with Bun

The SDK uses an embedded **Bun** binary to process the final output.

- **Build Performance**: Bun processes TS/JS files up to 10x faster than Node.js-based tools.
- **Tree-shaking**: Dead code is automatically removed during build.
- **Minification**: Scripts are delivered compressed.

### Zero-runtime CSS Extraction

The compiler analyzes `StyleClass` definitions and extracts them into static `.css` files at build time.

- **No CSS-in-JS Overhead**: Unlike modern web frameworks that compute styles at runtime, eQuantic.UI delivers static CSS, reducing the CPU work in the browser.
- **Cacheability**: CSS files can be cached independently of the logic bundles.
- **LCP Optimization**: Layout is applied as soon as the CSS is loaded, preventing Layout Shift (CLS).

### Code Splitting

- **Chunks per Page**: Each page generates its own JS bundle. The user downloads only what is necessary for the current route.
- **Lazy Loading**: Complex components and libraries can be loaded on demand.