@webbridge-native/observers

Performance API (marks, measures, PerformanceObserver) and requestIdleCallback polyfill for React Native.

Installation

npm install @webbridge-native/observers
# or
pnpm add @webbridge-native/observers

Usage

Performance API

import { WBPerformance, WBPerformanceObserver } from '@webbridge-native/observers';

const perf = new WBPerformance();

// Create marks
perf.mark('fetch-start');
await fetch('https://example.com/api');
perf.mark('fetch-end');

// Measure between marks
const measure = perf.measure('fetch-duration', 'fetch-start', 'fetch-end');
console.log(`Fetch took ${measure.duration}ms`);

// Measure with options
perf.measure('custom', { start: 0, end: 100 });

// Query entries
const marks = perf.getEntriesByType('mark');
const measures = perf.getEntriesByName('fetch-duration');

// Observe new entries
const observer = new WBPerformanceObserver((list, obs) => {
  for (const entry of list.getEntries()) {
    console.log(`${entry.name}: ${entry.duration}ms`);
  }
});

observer.observe({ entryTypes: ['measure'], performance: perf });

// Cleanup
observer.disconnect();
perf.clearMarks();
perf.clearMeasures();

requestIdleCallback

import { wbRequestIdleCallback, wbCancelIdleCallback } from '@webbridge-native/observers';

const id = wbRequestIdleCallback((deadline) => {
  while (deadline.timeRemaining() > 0) {
    // Do non-urgent work
    processNextItem();
  }
});

// Cancel if needed
wbCancelIdleCallback(id);

// With timeout (force execution after 1000ms)
wbRequestIdleCallback(
  (deadline) => {
    if (deadline.didTimeout) {
      // Forced execution — do minimal work
    }
    doWork();
  },
  { timeout: 1000 },
);

API

WBPerformance

| Method | Description | |--------|-------------| | now() | High-resolution timestamp relative to timeOrigin | | mark(name, options?) | Create a named timestamp | | measure(name, start?, end?) | Measure duration between marks | | getEntries() | Get all entries | | getEntriesByType(type) | Filter entries by type | | getEntriesByName(name, type?) | Filter entries by name | | clearMarks(name?) | Remove marks | | clearMeasures(name?) | Remove measures |

WBPerformanceObserver

| Method | Description | |--------|-------------| | observe({ entryTypes, performance }) | Start observing | | disconnect() | Stop observing | | takeRecords() | Get buffered entries |

requestIdleCallback

| Function | Description | |----------|-------------| | wbRequestIdleCallback(cb, opts?) | Schedule idle callback | | wbCancelIdleCallback(id) | Cancel scheduled callback |

License

MIT