WebOS Performance Monitoring

This document provides information about the performance monitoring system built into the WebOS platform.

Overview

The WebOS Performance Monitoring system is a development tool that tracks, analyzes, and optimizes application performance in real-time. It helps identify performance bottlenecks without modifying component behavior.

Key Features

• Non-invasive Monitoring: Monitors components without modifying their code
• Advanced Metrics: Tracks render counts, component lifetimes, and render time
• Visual Dashboard: Interactive panel toggled with Alt+P
• Zero Production Impact: Automatically disabled in production environments

Adding Monitoring to Components

Using the HOC Pattern

The Higher-Order Component (HOC) pattern is ideal for class components or when you want to monitor all instances of a component:

// components/window.js
import React from 'react';
import { withPerformanceMonitoring } from '@/utils/performance-monitor';
 
function Window({ title, children, onClose }) {
  return (
    <div className="window">
      <div className="window-header">
        <div className="window-title">{title}</div>
        <button onClick={onClose}>×</button>
      </div>
      <div className="window-content">{children}</div>
    </div>
  );
}
 
// Only apply in development
export default process.env.NODE_ENV === 'development'
  ? withPerformanceMonitoring(Window, 'Window')
  : Window;

Using the Hook Pattern

The hook pattern is more flexible for functional components:

// components/desktop.js
import React from 'react';
import { usePerformanceMonitor } from '@/utils/performance-monitor';
 
export default function Desktop({ icons, background }) {
  // Only monitor in development
  if (process.env.NODE_ENV === 'development') {
    usePerformanceMonitor('Desktop');
  }
  
  return (
    <div 
      className="desktop" 
      style={{ backgroundImage: `url(${background})` }}
    >
      {icons.map(icon => (
        <DesktopIcon key={icon.id} icon={icon} />
      ))}
    </div>
  );
}

Performance Panel

The Performance Panel displays real-time metrics for all monitored components:

• Component Name: Identifier for the monitored component
• Render Count: Number of times the component rendered
• Last Render Time: Duration of the most recent render
• Average Render Time: Average duration across all renders
• Component Status: Whether the component is currently mounted

The panel can be toggled with Alt+P (customizable) and allows filtering components by name.

Performance Optimization Tips

The monitoring system can help identify several common performance issues:

1. Excessive Re-renders:

   • Components with high render counts may need memoization with React.memo
   • Use useCallback for event handlers passed to child components
   • Apply useMemo to expensive calculations

2. Slow Render Times:

   • Break down large components into smaller, focused components
   • Delay expensive calculations with useEffect
   • Consider virtualization for long lists

3. Component Lifecycle Issues:

   • Components that mount and unmount frequently may indicate inefficient design
   • Evaluate the component hierarchy to minimize remounts
   • Use keys appropriately to preserve component state

Configuration Options

The Performance Monitoring system can be configured with the following options:

• Enable/disable the entire system (default: enabled in development only)
• Set panel toggle shortcut (default: ‘alt+p’)
• Configure render warning threshold (default: 16ms)
• Set maximum render history to keep per component
• Define component ignore patterns
• Enable/disable console warnings for performance issues

Example configuration:

// config/performance-config.js
export const performanceConfig = {
  enabled: process.env.NODE_ENV === 'development',
  toggleShortcut: 'alt+p',
  renderWarningThreshold: 16, // ms
  maxRenderHistory: 50
};

Future Enhancements

Planned enhancements to the monitoring system include:

1. Timeline View: Visual representation of component rendering over time
2. Dependency Tracking: Identify unnecessary re-renders by tracking prop changes
3. Bundle Size Analysis: Integration with webpack analysis
4. Interaction Tracing: Track performance from user interaction to final render
5. Network Performance: Monitor API calls and their impact on rendering