Chapter 16: Advanced Features and Latest Developments

Haiyue
45min

Chapter 16: Advanced Features and Latest Developments

Learning Objectives

  1. Master advanced features and APIs of Chrome extensions
  2. Understand the latest features of Manifest V3
  3. Learn to use WebAssembly to enhance extension performance
  4. Understand AI integration and machine learning applications
  5. Master cross-browser compatibility development

1. Manifest V3 Advanced Features

1.1 Advanced Service Worker Applications

Manifest V3 introduces Service Workers to replace Background Pages, providing more powerful functionality.

// src/background/advanced-service-worker.js
class AdvancedServiceWorker {
  constructor() {
    this.initializeModules();
    this.setupAdvancedListeners();
    this.startBackgroundTasks();
  }

  initializeModules() {
    // Modular initialization
    this.modules = {
      networking: new NetworkingModule(),
      ai: new AIModule(),
      analytics: new AdvancedAnalytics(),
      sync: new CrossPlatformSync(),
      security: new SecurityModule()
    };
  }

  setupAdvancedListeners() {
    // Advanced event listeners
    this.setupNetworkListeners();
    this.setupTabGroupListeners();
    this.setupDeclarativeNetRequestListeners();
    this.setupUserScriptListeners();
  }

  setupNetworkListeners() {
    // Use Fetch API for advanced network requests
    self.addEventListener('fetch', (event) => {
      if (event.request.url.includes('/api/')) {
        event.respondWith(this.handleApiRequest(event.request));
      }
    });

    // Monitor network status changes
    self.addEventListener('online', () => {
      this.handleOnlineStatusChange(true);
    });

    self.addEventListener('offline', () => {
      this.handleOnlineStatusChange(false);
    });
  }

  async handleApiRequest(request) {
    try {
      // Add authentication headers
      const enhancedRequest = new Request(request.url, {
        method: request.method,
        headers: {
          ...Object.fromEntries(request.headers),
          'Authorization': await this.getAuthToken(),
          'X-Extension-Version': chrome.runtime.getManifest().version
        },
        body: request.body
      });

      // Send enhanced request
      const response = await fetch(enhancedRequest);

      // Cache response
      if (response.ok) {
        await this.cacheResponse(request.url, response.clone());
      }

      return response;
    } catch (error) {
      console.error('API request failed:', error);
      // Try returning from cache
      return this.getCachedResponse(request.url);
    }
  }

  setupTabGroupListeners() {
    // Chrome 89+ Tab Groups API
    if (chrome.tabGroups) {
      chrome.tabGroups.onCreated.addListener((group) => {
        this.handleTabGroupCreated(group);
      });

      chrome.tabGroups.onUpdated.addListener((group) => {
        this.handleTabGroupUpdated(group);
      });

      chrome.tabGroups.onRemoved.addListener((group) => {
        this.handleTabGroupRemoved(group);
      });
    }
  }

  async handleTabGroupCreated(group) {
    // Smart grouping suggestions
    const suggestions = await this.generateGroupSuggestions(group);

    if (suggestions.length > 0) {
      // Send suggestions to user
      await chrome.notifications.create({
        type: 'basic',
        iconUrl: 'assets/icon48.png',
        title: 'Smart Tab Grouping',
        message: `We found ${suggestions.length} tabs that might belong to this group.`,
        buttons: [
          { title: 'Apply Suggestions' },
          { title: 'Dismiss' }
        ]
      });
    }
  }

  setupDeclarativeNetRequestListeners() {
    // Declarative Net Request API for advanced request blocking
    chrome.declarativeNetRequest.onRuleMatchedDebug.addListener((info) => {
      console.log('Rule matched:', info);
      this.modules.analytics.trackRuleMatch(info);
    });
  }

  setupUserScriptListeners() {
    // User Scripts API (Chrome 102+)
    if (chrome.userScripts) {
      chrome.userScripts.onBeforeScript.addListener((details) => {
        this.handleUserScriptExecution(details);
      });
    }
  }

  startBackgroundTasks() {
    // Start background tasks
    this.startPeriodicTasks();
    this.startIdleDetection();
    this.startPerformanceMonitoring();
  }

  startPeriodicTasks() {
    // Use chrome.alarms for scheduled tasks
    chrome.alarms.create('data-sync', { periodInMinutes: 30 });
    chrome.alarms.create('cleanup', { periodInMinutes: 60 });
    chrome.alarms.create('analytics-report', { periodInMinutes: 1440 }); // 24 hours

    chrome.alarms.onAlarm.addListener((alarm) => {
      this.handleAlarm(alarm);
    });
  }

  async handleAlarm(alarm) {
    switch (alarm.name) {
      case 'data-sync':
        await this.modules.sync.performSync();
        break;
      case 'cleanup':
        await this.performCleanup();
        break;
      case 'analytics-report':
        await this.modules.analytics.generateReport();
        break;
    }
  }

  startIdleDetection() {
    // Detect user idle state
    chrome.idle.setDetectionInterval(60); // 1 minute

    chrome.idle.onStateChanged.addListener((state) => {
      this.handleIdleStateChange(state);
    });
  }

  handleIdleStateChange(state) {
    switch (state) {
      case 'idle':
        // Execute low-priority tasks when user is idle
        this.performIdleTasks();
        break;
      case 'active':
        // User returns to active state
        this.resumeActiveTasks();
        break;
      case 'locked':
        // Pause non-critical tasks when screen is locked
        this.pauseNonCriticalTasks();
        break;
    }
  }

  async performIdleTasks() {
    // Tasks executed during idle time
    await this.optimizeDatabase();
    await this.preloadData();
    await this.performMaintenance();
  }

  // Advanced Web Streams API usage
  async processLargeDataStream(dataUrl) {
    try {
      const response = await fetch(dataUrl);
      const reader = response.body.getReader();
      const stream = new ReadableStream({
        start(controller) {
          function pump() {
            return reader.read().then(({ done, value }) => {
              if (done) {
                controller.close();
                return;
              }

              // Process data chunk
              const processedChunk = this.processDataChunk(value);
              controller.enqueue(processedChunk);

              return pump();
            });
          }
          return pump();
        }
      });

      return stream;
    } catch (error) {
      console.error('Stream processing failed:', error);
      throw error;
    }
  }

  processDataChunk(chunk) {
    // Data chunk processing logic
    return new TextDecoder().decode(chunk);
  }
}

// Networking module
class NetworkingModule {
  constructor() {
    this.requestQueue = [];
    this.rateLimiter = new RateLimiter();
    this.retryManager = new RetryManager();
  }

  async enhancedFetch(url, options = {}) {
    // Enhanced fetch wrapper
    const enhancedOptions = {
      ...options,
      headers: {
        'User-Agent': `Chrome Extension/${chrome.runtime.getManifest().version}`,
        'Accept': 'application/json',
        ...options.headers
      }
    };

    // Rate limiting
    await this.rateLimiter.waitForSlot();

    // Retry mechanism
    return this.retryManager.execute(async () => {
      const response = await fetch(url, enhancedOptions);

      if (!response.ok) {
        throw new Error(`HTTP ${response.status}: ${response.statusText}`);
      }

      return response;
    });
  }
}

// Rate limiter
class RateLimiter {
  constructor(maxRequests = 100, windowMs = 60000) {
    this.maxRequests = maxRequests;
    this.windowMs = windowMs;
    this.requests = [];
  }

  async waitForSlot() {
    const now = Date.now();

    // Clean up expired request records
    this.requests = this.requests.filter(time => now - time < this.windowMs);

    if (this.requests.length >= this.maxRequests) {
      const oldestRequest = Math.min(...this.requests);
      const waitTime = this.windowMs - (now - oldestRequest);

      if (waitTime > 0) {
        await new Promise(resolve => setTimeout(resolve, waitTime));
      }
    }

    this.requests.push(now);
  }
}

// Retry manager
class RetryManager {
  constructor(maxRetries = 3, baseDelay = 1000) {
    this.maxRetries = maxRetries;
    this.baseDelay = baseDelay;
  }

  async execute(operation) {
    let lastError;

    for (let attempt = 0; attempt <= this.maxRetries; attempt++) {
      try {
        return await operation();
      } catch (error) {
        lastError = error;

        if (attempt === this.maxRetries) {
          break;
        }

        // Exponential backoff delay
        const delay = this.baseDelay * Math.pow(2, attempt);
        await new Promise(resolve => setTimeout(resolve, delay));
      }
    }

    throw lastError;
  }
}

// Initialize advanced Service Worker
new AdvancedServiceWorker();

1.2 Data Structures and Type Definitions

Core Data Structures

// Tab group data structure
interface TabGroup {
  id: number;
  color: string;
  title: string;
  collapsed: boolean;
  windowId: number;
}

// Network request data structure
interface NetworkRequest {
  url: string;
  method: string;
  headers: Record<string, string>;
  body?: string;
  timestamp: number;
}

// Performance metrics data
interface PerformanceMetrics {
  memory_usage: number[];
  cpu_usage: number[];
  network_latency: number[];
  user_interactions: any[];
}

// AI model configuration
interface AIModels {
  content_classifier: ContentClassifier;
  intent_detector: IntentDetector;
  anomaly_detector: AnomalyDetector;
  recommendation_engine: RecommendationEngine;
}

// Security policy configuration
interface SecurityPolicies {
  csp_violations: any[];
  suspicious_activities: any[];
  permission_usage: Record<string, any>;
  data_access_logs: any[];
}

Chrome Extension Advanced Features Reference

Tab Grouping Feature Example

// Handle tab group operations
async function handleTabGroupOperation(operation, data) {
  switch (operation) {
    case 'create':
      return await createTabGroup(data);
    case 'update':
      return await updateTabGroup(data);
    case 'remove':
      return await removeTabGroup(data);
    case 'suggest':
      return await suggestTabGrouping(data);
  }
}

// Create tab group
async function createTabGroup(data) {
  const group = await chrome.tabGroups.create({
    tabIds: data.tabIds,
    createProperties: {
      title: data.title || 'New Group',
      color: data.color || 'blue',
      collapsed: data.collapsed || false
    }
  });

  return {
    group,
    suggestions: await generateGroupSuggestions(group)
  };
}

// Smart tab grouping suggestions
async function suggestTabGrouping(data) {
  const tabs = data.tabs || [];
  const classifications = [];

  // Use AI for content classification
  for (const tab of tabs) {
    const classification = await classifyContent(tab.url, tab.title);
    classifications.push({
      tab,
      category: classification.category,
      confidence: classification.confidence
    });
  }

  // Group by category
  const groups = {};
  for (const item of classifications) {
    const category = item.category;
    if (!groups[category]) {
      groups[category] = [];
    }
    groups[category].push(item.tab);
  }

  // Generate suggestions
  const suggestions = [];
  for (const [category, tabList] of Object.entries(groups)) {
    if (tabList.length >= 2) {
      suggestions.push({
        title: `${category.charAt(0).toUpperCase() + category.slice(1)} Group`,
        tabs: tabList,
        color: getCategoryColor(category),
        confidence: classifications
          .filter(c => c.category === category)
          .reduce((sum, c) => sum + c.confidence, 0) / tabList.length
      });
    }
  }

  return suggestions;
}

// Get category color
function getCategoryColor(category) {
  const colorMap = {
    'work': 'blue',
    'entertainment': 'red',
    'shopping': 'green',
    'social': 'pink',
    'news': 'orange',
    'development': 'purple',
    'education': 'cyan'
  };
  return colorMap[category] || 'grey';
}

Declarative Network Request Handling

// Handle declarative network requests
async function handleDeclarativeNetRequest(requestData) {
  const rules = requestData.rules || [];

  for (const rule of rules) {
    await applyNetworkRule(rule);
  }

  return {
    rules_applied: rules.length,
    timestamp: new Date().toISOString()
  };
}

// Apply network rule
async function applyNetworkRule(rule) {
  const ruleType = rule.action?.type;

  switch (ruleType) {
    case 'block':
      await chrome.declarativeNetRequest.updateDynamicRules({
        addRules: [rule],
        removeRuleIds: []
      });
      break;
    case 'redirect':
      // Handle redirect rules
      break;
    case 'modifyHeaders':
      // Handle request header modification
      break;
  }
}

Cross-Browser Compatibility Configuration

{
  "firefox": {
    "supported": true,
    "api_differences": {
      "storage": "browser.storage instead of chrome.storage",
      "tabs": "browser.tabs instead of chrome.tabs",
      "runtime": "browser.runtime instead of chrome.runtime"
    },
    "manifest_adjustments": {
      "background": {
        "scripts": ["background.js"],
        "persistent": false
      },
      "browser_specific_settings": {
        "gecko": {
          "id": "extension@example.com",
          "strict_min_version": "57.0"
        }
      }
    }
  },
  "edge": {
    "supported": true,
    "api_differences": {
      "notifications": "Limited notification support",
      "nativeMessaging": "Requires additional permissions"
    },
    "manifest_adjustments": {
      "minimum_edge_version": "79.0",
      "ms_store_compatibility": true
    }
  }
}

Advanced Security Configuration

{
  "content_security_policy": {
    "extension_pages": "script-src 'self' 'wasm-unsafe-eval'; object-src 'none';",
    "content_scripts": "script-src 'self'; object-src 'none';",
    "sandbox": "sandbox allow-scripts allow-forms allow-popups allow-modals;"
  },
  "permission_management": {
    "required": ["storage", "tabs", "declarativeNetRequest"],
    "optional": ["tabGroups", "downloads", "bookmarks"]
  }
}

Performance Monitoring Data Structure

// Get performance report
function getPerformanceReport() {
  return {
    memory_usage: calculateMemoryStats(),
    cpu_usage: calculateCpuStats(),
    network_performance: calculateNetworkStats(),
    user_experience_metrics: calculateUxMetrics(),
    recommendations: generatePerformanceRecommendations()
  };
}

// Calculate memory statistics
function calculateMemoryStats() {
  const memoryData = performanceMetrics.memory_usage || [];

  if (memoryData.length === 0) {
    return { status: 'no_data' };
  }

  const average = memoryData.reduce((sum, val) => sum + val, 0) / memoryData.length;
  const peak = Math.max(...memoryData);
  const trend = memoryData[memoryData.length - 1] > memoryData[0] ? 'increasing' : 'decreasing';

  return {
    average_mb: average,
    peak_mb: peak,
    trend
  };
}

AI Feature Integration Example

// Content classifier
class ContentClassifier {
  async classify(url, title) {
    const text = `${url} ${title}`.toLowerCase();

    if (['github', 'stackoverflow', 'dev', 'code'].some(word => text.includes(word))) {
      return { category: 'development', confidence: 0.9 };
    } else if (['youtube', 'netflix', 'game'].some(word => text.includes(word))) {
      return { category: 'entertainment', confidence: 0.8 };
    } else if (['amazon', 'shop', 'buy'].some(word => text.includes(word))) {
      return { category: 'shopping', confidence: 0.85 };
    }

    return { category: 'general', confidence: 0.6 };
  }

  async analyze(content) {
    const text = content.text || '';
    const positiveWords = ['good', 'great', 'excellent', 'amazing', 'wonderful'];
    const negativeWords = ['bad', 'terrible', 'awful', 'horrible', 'worst'];

    const positiveCount = positiveWords.filter(word =>
      text.toLowerCase().includes(word)
    ).length;

    const negativeCount = negativeWords.filter(word =>
      text.toLowerCase().includes(word)
    ).length;

    let sentiment;
    if (positiveCount > negativeCount) {
      sentiment = 'positive';
    } else if (negativeCount > positiveCount) {
      sentiment = 'negative';
    } else {
      sentiment = 'neutral';
    }

    return {
      sentiment,
      topics: ['technology', 'web development'],
      language: 'en',
      quality_score: 0.7,
      confidence: 0.8
    };
  }
}

// Intent detector
class IntentDetector {
  async detectIntent(userAction, context) {
    const intentPatterns = {
      'search': /\b(find|search|look for)\b/i,
      'purchase': /\b(buy|purchase|order)\b/i,
      'learn': /\b(learn|study|understand)\b/i,
      'entertainment': /\b(watch|play|enjoy)\b/i
    };

    for (const [intent, pattern] of Object.entries(intentPatterns)) {
      if (pattern.test(userAction)) {
        return { intent, confidence: 0.8 };
      }
    }

    return { intent: 'unknown', confidence: 0.3 };
  }
}

// Anomaly detector
class AnomalyDetector {
  async detectAnomalies(data) {
    const anomalies = [];

    for (const item of data) {
      if ((item.value || 0) > 1000) {
        anomalies.push({
          item,
          anomaly_type: 'high_value',
          severity: 'medium',
          timestamp: new Date().toISOString()
        });
      }
    }

    return anomalies;
  }
}

// Recommendation engine
class RecommendationEngine {
  async generateRecommendations(userData, context) {
    return [
      {
        type: 'bookmark_organization',
        title: 'Organize your bookmarks',
        description: 'Group similar bookmarks together',
        confidence: 0.9
      },
      {
        type: 'productivity_tip',
        title: 'Use keyboard shortcuts',
        description: 'Speed up your browsing with shortcuts',
        confidence: 0.7
      }
    ];
  }
}

2. WebAssembly Integration

2.1 High-Performance Computing Module

// src/modules/wasm-integration.js
class WebAssemblyManager {
  constructor() {
    this.modules = new Map();
    this.initialized = false;
  }

  async initialize() {
    if (this.initialized) return;

    try {
      // Load various WASM modules
      await Promise.all([
        this.loadModule('image-processor', '/wasm/image_processor.wasm'),
        this.loadModule('crypto-hasher', '/wasm/crypto_hasher.wasm'),
        this.loadModule('data-compressor', '/wasm/data_compressor.wasm'),
        this.loadModule('ml-inference', '/wasm/ml_inference.wasm')
      ]);

      this.initialized = true;
      console.log('✅ WebAssembly modules loaded successfully');
    } catch (error) {
      console.error('❌ Failed to load WebAssembly modules:', error);
      throw error;
    }
  }

  async loadModule(name, wasmPath) {
    try {
      const wasmModule = await WebAssembly.instantiateStreaming(
        fetch(chrome.runtime.getURL(wasmPath)),
        {
          env: {
            memory: new WebAssembly.Memory({ initial: 256, maximum: 512 }),
            table: new WebAssembly.Table({ initial: 1, element: 'anyfunc' }),
            memoryBase: 0,
            tableBase: 0,
            // Provide JavaScript functions for WASM to call
            jsLog: (ptr, len) => {
              const message = this.readString(ptr, len);
              console.log(`[WASM:${name}] ${message}`);
            },
            jsError: (ptr, len) => {
              const message = this.readString(ptr, len);
              console.error(`[WASM:${name}] ${message}`);
            }
          }
        }
      );

      this.modules.set(name, {
        instance: wasmModule.instance,
        exports: wasmModule.instance.exports,
        memory: wasmModule.instance.exports.memory
      });

      console.log(`📦 Loaded WASM module: ${name}`);
    } catch (error) {
      console.error(`Failed to load WASM module ${name}:`, error);
      throw error;
    }
  }

  readString(ptr, len) {
    const memory = this.modules.get('current')?.memory;
    if (!memory) return '';

    const bytes = new Uint8Array(memory.buffer, ptr, len);
    return new TextDecoder().decode(bytes);
  }

  writeString(moduleName, str) {
    const module = this.modules.get(moduleName);
    if (!module) throw new Error(`Module ${moduleName} not found`);

    const bytes = new TextEncoder().encode(str);
    const ptr = module.exports.allocate(bytes.length);
    const memory = new Uint8Array(module.memory.buffer);
    memory.set(bytes, ptr);

    return { ptr, len: bytes.length };
  }

  async processImage(imageData, operations) {
    const module = this.modules.get('image-processor');
    if (!module) throw new Error('Image processor module not loaded');

    try {
      // Write image data to WASM memory
      const imagePtr = this.writeImageData(module, imageData);

      // Call WASM function to process image
      const resultPtr = module.exports.process_image(
        imagePtr,
        imageData.width,
        imageData.height,
        JSON.stringify(operations)
      );

      // Read processing result
      const processedData = this.readImageData(module, resultPtr, imageData.width, imageData.height);

      // Cleanup memory
      module.exports.deallocate(imagePtr);
      module.exports.deallocate(resultPtr);

      return processedData;
    } catch (error) {
      console.error('Image processing error:', error);
      throw error;
    }
  }

  writeImageData(module, imageData) {
    const totalSize = imageData.width * imageData.height * 4; // RGBA
    const ptr = module.exports.allocate(totalSize);
    const memory = new Uint8ClampedArray(module.memory.buffer);

    // Copy image data to WASM memory
    memory.set(imageData.data, ptr);

    return ptr;
  }

  readImageData(module, ptr, width, height) {
    const totalSize = width * height * 4;
    const memory = new Uint8ClampedArray(module.memory.buffer, ptr, totalSize);

    return new ImageData(
      new Uint8ClampedArray(memory),
      width,
      height
    );
  }

  async computeHash(data, algorithm = 'sha256') {
    const module = this.modules.get('crypto-hasher');
    if (!module) throw new Error('Crypto hasher module not loaded');

    try {
      // Write data
      const dataPtr = module.exports.allocate(data.length);
      const memory = new Uint8Array(module.memory.buffer);
      memory.set(new Uint8Array(data), dataPtr);

      // Compute hash
      const hashPtr = module.exports.compute_hash(dataPtr, data.length, algorithm);

      // Read hash result
      const hashLength = module.exports.get_hash_length(algorithm);
      const hashData = new Uint8Array(module.memory.buffer, hashPtr, hashLength);

      // Convert to hexadecimal string
      const hexHash = Array.from(hashData)
        .map(b => b.toString(16).padStart(2, '0'))
        .join('');

      // Cleanup memory
      module.exports.deallocate(dataPtr);
      module.exports.deallocate(hashPtr);

      return hexHash;
    } catch (error) {
      console.error('Hash computation error:', error);
      throw error;
    }
  }

  async compressData(data, compressionLevel = 6) {
    const module = this.modules.get('data-compressor');
    if (!module) throw new Error('Data compressor module not loaded');

    try {
      // Write original data
      const inputPtr = module.exports.allocate(data.length);
      const memory = new Uint8Array(module.memory.buffer);
      memory.set(new Uint8Array(data), inputPtr);

      // Compress data
      const result = module.exports.compress_data(inputPtr, data.length, compressionLevel);
      const compressedSize = module.exports.get_compressed_size(result);
      const compressedPtr = module.exports.get_compressed_data(result);

      // Read compression result
      const compressedData = new Uint8Array(module.memory.buffer, compressedPtr, compressedSize);

      // Cleanup memory
      module.exports.deallocate(inputPtr);
      module.exports.free_compression_result(result);

      return {
        data: new Uint8Array(compressedData),
        originalSize: data.length,
        compressedSize: compressedSize,
        ratio: compressedSize / data.length
      };
    } catch (error) {
      console.error('Data compression error:', error);
      throw error;
    }
  }

  async runMLInference(model, inputData) {
    const module = this.modules.get('ml-inference');
    if (!module) throw new Error('ML inference module not loaded');

    try {
      // Load model
      const modelId = await this.loadMLModel(module, model);

      // Prepare input data
      const inputPtr = this.writeMLInput(module, inputData);

      // Run inference
      const outputPtr = module.exports.run_inference(modelId, inputPtr);

      // Read output
      const output = this.readMLOutput(module, outputPtr);

      // Cleanup resources
      module.exports.deallocate(inputPtr);
      module.exports.deallocate(outputPtr);

      return output;
    } catch (error) {
      console.error('ML inference error:', error);
      throw error;
    }
  }

  async loadMLModel(module, modelConfig) {
    const configStr = JSON.stringify(modelConfig);
    const { ptr, len } = this.writeString('ml-inference', configStr);

    const modelId = module.exports.load_model(ptr, len);

    module.exports.deallocate(ptr);

    return modelId;
  }

  writeMLInput(module, inputData) {
    const serialized = new Float32Array(inputData.flat());
    const ptr = module.exports.allocate(serialized.byteLength);
    const memory = new Uint8Array(module.memory.buffer);

    memory.set(new Uint8Array(serialized.buffer), ptr);

    return ptr;
  }

  readMLOutput(module, outputPtr) {
    // Get output dimensions
    const dims = module.exports.get_output_dims(outputPtr);
    const totalSize = module.exports.get_output_size(outputPtr);

    // Read output data
    const dataPtr = module.exports.get_output_data(outputPtr);
    const outputData = new Float32Array(module.memory.buffer, dataPtr, totalSize);

    return {
      data: Array.from(outputData),
      dimensions: dims
    };
  }

  getModuleStats() {
    const stats = {};

    for (const [name, module] of this.modules) {
      const memory = module.memory;
      stats[name] = {
        memorySize: memory.buffer.byteLength,
        memoryPages: memory.buffer.byteLength / 65536,
        exports: Object.keys(module.exports)
      };
    }

    return stats;
  }

  async benchmark(moduleName, operation, iterations = 1000) {
    const module = this.modules.get(moduleName);
    if (!module) throw new Error(`Module ${moduleName} not found`);

    const startTime = performance.now();

    for (let i = 0; i < iterations; i++) {
      await operation(module);
    }

    const endTime = performance.now();
    const totalTime = endTime - startTime;

    return {
      totalTime,
      averageTime: totalTime / iterations,
      operationsPerSecond: 1000 / (totalTime / iterations)
    };
  }
}

// Usage example
class WAMSImageProcessor {
  constructor() {
    this.wasmManager = new WebAssemblyManager();
  }

  async initialize() {
    await this.wasmManager.initialize();
  }

  async processScreenshot(canvas) {
    const ctx = canvas.getContext('2d');
    const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);

    // Use WASM for high-performance image processing
    const operations = {
      brightness: 1.2,
      contrast: 1.1,
      blur: 2,
      noise_reduction: true
    };

    const processedData = await this.wasmManager.processImage(imageData, operations);

    // Draw processing result back to canvas
    ctx.putImageData(processedData, 0, 0);

    return canvas;
  }

  async compressImageData(imageData) {
    // Convert ImageData to byte array
    const rawData = imageData.data.buffer;

    // Compress using WASM
    const compressed = await this.wasmManager.compressData(rawData, 9);

    console.log(`Compression ratio: ${compressed.ratio.toFixed(2)}`);

    return compressed;
  }
}

// Initialize WASM manager
const wasmManager = new WebAssemblyManager();

3. AI and Machine Learning Integration

3.1 In-Browser Machine Learning

// src/modules/ai-integration.js
class AIManager {
  constructor() {
    this.models = new Map();
    this.tfjs = null;
    this.initialized = false;
  }

  async initialize() {
    if (this.initialized) return;

    try {
      // Dynamically load TensorFlow.js
      await this.loadTensorFlowJS();

      // Load pre-trained models
      await this.loadModels();

      this.initialized = true;
      console.log('🤖 AI Manager initialized successfully');
    } catch (error) {
      console.error('❌ Failed to initialize AI Manager:', error);
      throw error;
    }
  }

  async loadTensorFlowJS() {
    // Dynamically load TensorFlow.js
    const script = document.createElement('script');
    script.src = 'https://cdn.jsdelivr.net/npm/@tensorflow/tfjs@4.0.0/dist/tf.min.js';

    return new Promise((resolve, reject) => {
      script.onload = () => {
        this.tfjs = window.tf;
        resolve();
      };
      script.onerror = reject;
      document.head.appendChild(script);
    });
  }

  async loadModels() {
    const modelConfigs = [
      {
        name: 'toxicity',
        url: 'https://storage.googleapis.com/tfjs-models/tfjs/toxicity_classifier/model.json',
        type: 'text-classification'
      },
      {
        name: 'universal-sentence-encoder',
        url: 'https://storage.googleapis.com/tfjs-models/tfjs/universal_sentence_encoder/model.json',
        type: 'text-embedding'
      },
      {
        name: 'mobilenet',
        url: 'https://storage.googleapis.com/tfjs-models/tfjs/mobilenet_v2_1.0_224/model.json',
        type: 'image-classification'
      }
    ];

    for (const config of modelConfigs) {
      try {
        const model = await this.tfjs.loadLayersModel(config.url);
        this.models.set(config.name, {
          model,
          type: config.type,
          loaded: true
        });
        console.log(`📦 Loaded AI model: ${config.name}`);
      } catch (error) {
        console.warn(`⚠️ Failed to load model ${config.name}:`, error);
      }
    }
  }

  async analyzeText(text, analysisType = 'sentiment') {
    switch (analysisType) {
      case 'toxicity':
        return await this.detectToxicity(text);
      case 'sentiment':
        return await this.analyzeSentiment(text);
      case 'embedding':
        return await this.getTextEmbedding(text);
      case 'intent':
        return await this.detectIntent(text);
      default:
        throw new Error(`Unsupported analysis type: ${analysisType}`);
    }
  }

  async detectToxicity(text) {
    const toxicityModel = this.models.get('toxicity');
    if (!toxicityModel) {
      throw new Error('Toxicity model not loaded');
    }

    try {
      const predictions = await toxicityModel.model.predict([text]);

      const results = {};
      const labels = ['identity_attack', 'insult', 'obscene', 'severe_toxicity', 'sexual_explicit', 'threat', 'toxicity'];

      predictions.forEach((prediction, index) => {
        results[labels[index]] = {
          probability: prediction.dataSync()[0],
          match: prediction.dataSync()[0] > 0.7
        };
      });

      return {
        toxic: results.toxicity.match,
        confidence: results.toxicity.probability,
        categories: results
      };
    } catch (error) {
      console.error('Toxicity detection error:', error);
      return { toxic: false, confidence: 0, error: error.message };
    }
  }

  async analyzeSentiment(text) {
    // Use simple dictionary method for sentiment analysis
    // In production, this would use a more complex model
    const positiveWords = [
      'good', 'great', 'excellent', 'amazing', 'wonderful', 'fantastic',
      'awesome', 'brilliant', 'outstanding', 'perfect', 'love', 'like'
    ];

    const negativeWords = [
      'bad', 'terrible', 'awful', 'horrible', 'hate', 'dislike',
      'worst', 'disgusting', 'annoying', 'frustrating', 'disappointed'
    ];

    const words = text.toLowerCase().match(/\b\w+\b/g) || [];

    let positiveScore = 0;
    let negativeScore = 0;

    words.forEach(word => {
      if (positiveWords.includes(word)) positiveScore++;
      if (negativeWords.includes(word)) negativeScore++;
    });

    const totalWords = words.length;
    const sentimentScore = (positiveScore - negativeScore) / Math.max(totalWords, 1);

    let sentiment;
    if (sentimentScore > 0.1) sentiment = 'positive';
    else if (sentimentScore < -0.1) sentiment = 'negative';
    else sentiment = 'neutral';

    return {
      sentiment,
      score: sentimentScore,
      confidence: Math.abs(sentimentScore),
      details: {
        positive_words: positiveScore,
        negative_words: negativeScore,
        total_words: totalWords
      }
    };
  }

  async getTextEmbedding(text) {
    const useModel = this.models.get('universal-sentence-encoder');
    if (!useModel) {
      throw new Error('Universal Sentence Encoder not loaded');
    }

    try {
      const embedding = await useModel.model.embed([text]);
      const values = await embedding.data();

      return {
        embedding: Array.from(values),
        dimensions: embedding.shape[1]
      };
    } catch (error) {
      console.error('Text embedding error:', error);
      throw error;
    }
  }

  async detectIntent(text) {
    // Simple implementation of intent detection
    const intents = {
      search: /\b(search|find|look for|where is|what is)\b/i,
      purchase: /\b(buy|purchase|order|get|want to buy)\b/i,
      support: /\b(help|support|problem|issue|bug)\b/i,
      information: /\b(tell me|explain|how to|tutorial)\b/i,
      booking: /\b(book|reserve|schedule|appointment)\b/i,
      comparison: /\b(compare|vs|versus|better|best)\b/i
    };

    for (const [intent, pattern] of Object.entries(intents)) {
      if (pattern.test(text)) {
        return {
          intent,
          confidence: 0.8,
          matched_pattern: pattern.source
        };
      }
    }

    return {
      intent: 'unknown',
      confidence: 0.1,
      matched_pattern: null
    };
  }

  async analyzeImage(imageElement) {
    const mobilenetModel = this.models.get('mobilenet');
    if (!mobilenetModel) {
      throw new Error('MobileNet model not loaded');
    }

    try {
      // Preprocess image
      const tensor = this.tfjs.browser.fromPixels(imageElement)
        .resizeNearestNeighbor([224, 224])
        .expandDims()
        .div(127.5)
        .sub(1);

      // Run inference
      const predictions = await mobilenetModel.model.predict(tensor);

      // Get top 5 predictions
      const topPredictions = await this.getTopPredictions(predictions, 5);

      // Cleanup tensors
      tensor.dispose();
      predictions.dispose();

      return {
        predictions: topPredictions,
        model: 'mobilenet',
        timestamp: Date.now()
      };
    } catch (error) {
      console.error('Image analysis error:', error);
      throw error;
    }
  }

  async getTopPredictions(predictions, topK = 5) {
    const values = await predictions.data();
    const indices = Array.from(values)
      .map((prob, index) => ({ probability: prob, index }))
      .sort((a, b) => b.probability - a.probability)
      .slice(0, topK);

    // This needs ImageNet class labels
    const labels = await this.getImageNetLabels();

    return indices.map(({ probability, index }) => ({
      className: labels[index],
      probability: probability,
      index: index
    }));
  }

  async getImageNetLabels() {
    // Return ImageNet class labels (simplified version)
    return [
      'Egyptian cat', 'tabby cat', 'tiger cat', 'Persian cat', 'Siamese cat',
      'African elephant', 'Indian elephant', 'goldfish', 'great white shark',
      // ... more labels
    ];
  }

  async generateRecommendations(userBehavior, context) {
    // Generate recommendations based on user behavior and context
    const recommendations = [];

    // Analyze user behavior patterns
    const patterns = this.analyzeBehaviorPatterns(userBehavior);

    // Generate recommendations based on current context
    if (context.currentPage) {
      const pageAnalysis = await this.analyzePageContent(context.currentPage);
      recommendations.push(...this.generateContextualRecommendations(pageAnalysis));
    }

    // Generate recommendations based on historical behavior
    recommendations.push(...this.generateBehavioralRecommendations(patterns));

    // Rank and filter recommendations
    return this.rankRecommendations(recommendations);
  }

  analyzeBehaviorPatterns(userBehavior) {
    const patterns = {
      mostVisitedDomains: {},
      timePatterns: {},
      categoryPreferences: {},
      searchQueries: []
    };

    userBehavior.forEach(action => {
      // Analyze domain preferences
      if (action.url) {
        const domain = new URL(action.url).hostname;
        patterns.mostVisitedDomains[domain] =
          (patterns.mostVisitedDomains[domain] || 0) + 1;
      }

      // Analyze time patterns
      const hour = new Date(action.timestamp).getHours();
      patterns.timePatterns[hour] = (patterns.timePatterns[hour] || 0) + 1;

      // Analyze search queries
      if (action.type === 'search') {
        patterns.searchQueries.push(action.query);
      }
    });

    return patterns;
  }

  async analyzePageContent(pageUrl) {
    try {
      // Get page content
      const response = await fetch(pageUrl);
      const html = await response.text();

      // Extract text content
      const parser = new DOMParser();
      const doc = parser.parseFromString(html, 'text/html');
      const textContent = doc.body.textContent || '';

      // Analyze content
      const sentiment = await this.analyzeSentiment(textContent);
      const intent = await this.detectIntent(textContent);

      return {
        url: pageUrl,
        textLength: textContent.length,
        sentiment: sentiment.sentiment,
        intent: intent.intent,
        keywords: this.extractKeywords(textContent)
      };
    } catch (error) {
      console.error('Page content analysis error:', error);
      return { url: pageUrl, error: error.message };
    }
  }

  extractKeywords(text) {
    // Simple keyword extraction
    const words = text.toLowerCase()
      .match(/\b\w{4,}\b/g) || [];

    const wordFreq = {};
    words.forEach(word => {
      wordFreq[word] = (wordFreq[word] || 0) + 1;
    });

    return Object.entries(wordFreq)
      .sort(([,a], [,b]) => b - a)
      .slice(0, 10)
      .map(([word]) => word);
  }

  generateContextualRecommendations(pageAnalysis) {
    const recommendations = [];

    if (pageAnalysis.intent === 'search') {
      recommendations.push({
        type: 'tool',
        title: 'Enhanced Search',
        description: 'Try our advanced search features',
        priority: 0.8
      });
    }

    if (pageAnalysis.sentiment === 'negative') {
      recommendations.push({
        type: 'support',
        title: 'Need Help?',
        description: 'Our support team is here to help',
        priority: 0.9
      });
    }

    return recommendations;
  }

  generateBehavioralRecommendations(patterns) {
    const recommendations = [];

    // Recommendations based on most visited domains
    const topDomains = Object.entries(patterns.mostVisitedDomains)
      .sort(([,a], [,b]) => b - a)
      .slice(0, 3);

    topDomains.forEach(([domain, count]) => {
      recommendations.push({
        type: 'bookmark',
        title: `Quick access to ${domain}`,
        description: `You visit this site frequently (${count} times)`,
        priority: 0.7
      });
    });

    return recommendations;
  }

  rankRecommendations(recommendations) {
    return recommendations
      .sort((a, b) => b.priority - a.priority)
      .slice(0, 10); // Limit number of recommendations
  }

  // Model performance monitoring
  getModelPerformance() {
    const performance = {};

    for (const [name, modelInfo] of this.models) {
      if (modelInfo.loaded) {
        performance[name] = {
          loaded: true,
          memoryUsage: this.tfjs.memory().numBytes,
          numTensors: this.tfjs.memory().numTensors
        };
      } else {
        performance[name] = { loaded: false };
      }
    }

    return performance;
  }

  dispose() {
    // Cleanup all models and tensors
    for (const [name, modelInfo] of this.models) {
      if (modelInfo.model && typeof modelInfo.model.dispose === 'function') {
        modelInfo.model.dispose();
      }
    }

    this.models.clear();
    this.initialized = false;
  }
}

// Smart recommendation system
class SmartRecommendationEngine {
  constructor(aiManager) {
    this.aiManager = aiManager;
    this.userProfile = {};
    this.contextHistory = [];
  }

  async updateUserProfile(userAction) {
    // Update user profile
    const actionAnalysis = await this.aiManager.analyzeText(
      userAction.description || '',
      'intent'
    );

    if (!this.userProfile.interests) {
      this.userProfile.interests = {};
    }

    const intent = actionAnalysis.intent;
    this.userProfile.interests[intent] =
      (this.userProfile.interests[intent] || 0) + 1;

    // Record context history
    this.contextHistory.push({
      timestamp: Date.now(),
      action: userAction,
      intent: intent
    });

    // Keep last 100 contexts
    if (this.contextHistory.length > 100) {
      this.contextHistory.shift();
    }
  }

  async getPersonalizedRecommendations(currentContext) {
    const recommendations = await this.aiManager.generateRecommendations(
      this.contextHistory,
      currentContext
    );

    // Personalize recommendations based on user profile
    return recommendations.map(rec => ({
      ...rec,
      personalizedScore: this.calculatePersonalizationScore(rec)
    }));
  }

  calculatePersonalizationScore(recommendation) {
    const userInterests = this.userProfile.interests || {};
    const totalInteractions = Object.values(userInterests)
      .reduce((sum, count) => sum + count, 0);

    if (totalInteractions === 0) return recommendation.priority;

    const relevantInterest = userInterests[recommendation.type] || 0;
    const interestWeight = relevantInterest / totalInteractions;

    return recommendation.priority * (1 + interestWeight);
  }
}

// Initialize AI manager
const aiManager = new AIManager();
const recommendationEngine = new SmartRecommendationEngine(aiManager);
Advanced Development Tips
  1. Use WebAssembly for compute-intensive tasks
  2. Integrate machine learning models for intelligent analysis
  3. Implement cross-browser compatibility adaptation
  4. Use modern Web APIs to enhance functionality
  5. Optimize performance and memory usage
Performance Considerations
  • WebAssembly module loading may take time
  • AI models consume significant memory
  • Be mindful of performance limitations on mobile devices
  • Consider lazy loading and on-demand loading of models

Learning Summary

This chapter covered advanced features of Chrome extensions:

  1. Manifest V3 Advanced Features: Service Workers, Tab Groups, Declarative Net Request
  2. WebAssembly Integration: High-performance computing, image processing, data compression
  3. AI and Machine Learning: Text analysis, image recognition, smart recommendations
  4. Cross-Browser Compatibility: Firefox, Edge, Safari adaptation
  5. Modern Web Technologies: PWA features, advanced security, performance optimization

Mastering these advanced features will help developers build powerful, high-performance modern Chrome extensions.

Mermaid Technical Architecture Diagram

🔄 正在渲染 Mermaid 图表...

Categories