Performance Optimization

export default class MyPlugin implements Plugin {
  private memoryMonitor?: NodeJS.Timeout
 
  async activate(context: PluginContext) {
    // Enable memory monitoring in development
    if (context.isDevelopment) {
      this.memoryMonitor = setInterval(() => {
        const usage = context.getMemoryUsage()
        if (usage.heapUsed > usage.heapLimit * 0.8) {
          context.api.log('warn', `High memory usage: ${usage.heapUsed}MB`)
        }
      }, 10000)
    }
  }
 
  async deactivate() {
    if (this.memoryMonitor) {
      clearInterval(this.memoryMonitor)
    }
  }
}

// Use idle callback for background work
async function processInBackground(items: any[]) {
  for (const item of items) {
    await new Promise<void>((resolve) => {
      requestIdleCallback(() => {
        processItem(item)
        resolve()
      }, { timeout: 1000 })
    })
  }
}

// Bad - 1000 individual calls
for (const file of files) {
  await api.fs.readFile(file)
}
 
// Good - Single batch call
const contents = await api.fs.readFiles(files)

import { Plugin, PluginContext } from 'lokus-plugin-sdk'
 
export default class WasmPlugin implements Plugin {
  private wasmModule?: any
 
  async activate(context: PluginContext) {
    // Load WASM module
    const wasmPath = context.extensionPath + '/lib/compute.wasm'
    const wasmBuffer = await context.api.fs.readBinary(wasmPath)
 
    const wasmModule = await WebAssembly.instantiate(wasmBuffer, {
      env: {
        // Import functions from JavaScript
        log: (ptr: number, len: number) => {
          const memory = new Uint8Array(wasmModule.instance.exports.memory.buffer)
          const message = new TextDecoder().decode(memory.slice(ptr, ptr + len))
          console.log('WASM:', message)
        }
      }
    })
 
    this.wasmModule = wasmModule.instance.exports
 
    // Register command that uses WASM
    context.api.commands.register({
      id: 'wasmPlugin.compute',
      title: 'Run WASM Computation',
      handler: () => this.runComputation()
    })
  }
 
  private async runComputation() {
    if (!this.wasmModule) return
 
    // Call WASM function
    const input = new Float32Array([1, 2, 3, 4, 5])
    const inputPtr = this.allocateMemory(input.byteLength)
 
    const memory = new Uint8Array(this.wasmModule.memory.buffer)
    memory.set(new Uint8Array(input.buffer), inputPtr)
 
    // Execute WASM function
    const resultPtr = this.wasmModule.processArray(inputPtr, input.length)
 
    // Read result
    const result = new Float32Array(
      this.wasmModule.memory.buffer,
      resultPtr,
      input.length
    )
 
    console.log('WASM result:', Array.from(result))
  }
 
  private allocateMemory(size: number): number {
    return this.wasmModule.malloc(size)
  }
}

// src/lib.rs - Compile to WASM with wasm-pack
use wasm_bindgen::prelude::*;
 
#[wasm_bindgen]
pub struct TextAnalyzer {
    word_count: usize,
    char_count: usize,
}
 
#[wasm_bindgen]
impl TextAnalyzer {
    #[wasm_bindgen(constructor)]
    pub fn new() -> TextAnalyzer {
        TextAnalyzer {
            word_count: 0,
            char_count: 0,
        }
    }
 
    /// Analyze text and return statistics
    #[wasm_bindgen]
    pub fn analyze(&mut self, text: &str) -> JsValue {
        self.word_count = text.split_whitespace().count();
        self.char_count = text.chars().count();
 
        // Calculate additional metrics
        let line_count = text.lines().count();
        let avg_word_length = if self.word_count > 0 {
            self.char_count as f64 / self.word_count as f64
        } else {
            0.0
        };
 
        // Return as JSON
        serde_wasm_bindgen::to_value(&serde_json::json!({
            "words": self.word_count,
            "characters": self.char_count,
            "lines": line_count,
            "avgWordLength": avg_word_length,
        })).unwrap()
    }
 
    /// Find all occurrences of a pattern (fast regex matching)
    #[wasm_bindgen]
    pub fn find_pattern(&self, text: &str, pattern: &str) -> Vec<usize> {
        text.match_indices(pattern)
            .map(|(idx, _)| idx)
            .collect()
    }
}
 
// Build with: wasm-pack build --target web

import { Plugin, PluginContext } from 'lokus-plugin-sdk'
import init, { TextAnalyzer } from './wasm/text_analyzer'
 
export default class TextAnalyzerPlugin implements Plugin {
  private analyzer?: TextAnalyzer
 
  async activate(context: PluginContext) {
    // Initialize WASM module
    await init(context.extensionPath + '/wasm/text_analyzer_bg.wasm')
    this.analyzer = new TextAnalyzer()
 
    context.api.commands.register({
      id: 'textAnalyzer.analyze',
      title: 'Analyze Text',
      handler: async () => {
        const content = await context.api.editor.getContent()
        const stats = this.analyzer!.analyze(content)
 
        context.api.ui.showNotification(
          `Words: ${stats.words}, Characters: $\\{stats.characters\\}`,
          'info'
        )
      }
    })
  }
}

// worker.ts - Worker thread code
import { expose } from 'lokus-plugin-sdk/worker'
 
const workerAPI = {
  async processLargeFile(content: string) {
    // Heavy processing here
    const lines = content.split('\n')
    const processed = lines.map(line => {
      // Complex transformation
      return line.toUpperCase().split('').reverse().join('')
    })
    return processed.join('\n')
  },
 
  async analyzeContent(content: string) {
    // Complex analysis
    const words = content.split(/\s+/)
    const frequencies = new Map<string, number>()
 
    words.forEach(word => {
      frequencies.set(word, (frequencies.get(word) || 0) + 1)
    })
 
    return Array.from(frequencies.entries())
      .sort((a, b) => b[1] - a[1])
      .slice(0, 100)
  }
}
 
expose(workerAPI)

import { Plugin, PluginContext } from 'lokus-plugin-sdk'
import { wrap } from 'lokus-plugin-sdk/worker'
import type { Remote } from 'comlink'
 
export default class WorkerPlugin implements Plugin {
  private worker?: Remote<typeof workerAPI>
 
  async activate(context: PluginContext) {
    // Create worker thread
    const workerPath = context.extensionPath + '/dist/worker.js'
    this.worker = await context.createWorker(workerPath)
 
    context.api.commands.register({
      id: 'workerPlugin.process',
      title: 'Process in Worker',
      handler: async () => {
        const content = await context.api.editor.getContent()
 
        // Show progress
        await context.api.ui.withProgress({
          title: 'Processing...',
          location: 'notification'
        }, async (progress) => {
          // Call worker method
          const result = await this.worker!.processLargeFile(content)
 
          progress.report({ message: 'Done!', increment: 100 })
 
          await context.api.editor.setContent(result)
        })
      }
    })
  }
 
  async deactivate() {
    // Terminate worker
    this.worker?.[Symbol.dispose]()
  }
}

// Load heavy dependencies only when needed
async function processData() {
  const { heavyLibrary } = await import('./heavy-lib')
  return heavyLibrary.process()
}

// Use built-in debounce utilities
import { debounce } from 'lokus-plugin-sdk/utils'
 
const debouncedHandler = debounce((text) => {
  // Process text
}, 300)
 
// Use in event handlers
api.editor.onDidChangeTextDocument((event) => {
  debouncedHandler(event.document.getText())
})

// Cache expensive computations
const cache = new Map()
 
function expensiveOperation(key: string) {
  if (cache.has(key)) {
    return cache.get(key)
  }
 
  const result = computeExpensive(key)
  cache.set(key, result)
  return result
}
 
// LRU cache with size limit
import { LRUCache } from 'lokus-plugin-sdk/cache'
 
const lruCache = new LRUCache({ max: 100 })
 
function cachedComputation(key: string) {
  return lruCache.get(key, () => computeExpensive(key))
}

import { VirtualList } from 'lokus-plugin-sdk/ui'
 
const list = new VirtualList({
  container: containerElement,
  itemHeight: 30,
  items: largeDataArray,
  renderItem: (item, index) => {
    return `<div class="item">${item.name}</div>`
  }
})
 
// Only renders visible items

import { throttle } from 'lokus-plugin-sdk/utils'
 
const throttledHandler = throttle((event) => {
  // Handle scroll event
  updateUI(event)
}, 100) // Max once per 100ms
 
window.addEventListener('scroll', throttledHandler)

// Bad - Multiple reflows
for (const item of items) {
  element.appendChild(createItemElement(item))
}
 
// Good - Single reflow
const fragment = document.createDocumentFragment()
for (const item of items) {
  fragment.appendChild(createItemElement(item))
}
element.appendChild(fragment)

export default class MyPlugin implements Plugin {
  async activate(context: PluginContext) {
    // Performance mark
    performance.mark('plugin-activation-start')
 
    // Your activation code here
    await this.initialize()
 
    // Performance measure
    performance.mark('plugin-activation-end')
    performance.measure(
      'plugin-activation',
      'plugin-activation-start',
      'plugin-activation-end'
    )
 
    // Log performance metrics
    const measure = performance.getEntriesByName('plugin-activation')[0]
    context.api.log('info', `Plugin activated in ${measure.duration}ms`)
  }
}