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Version: Next

cacheLife Function

The cacheLife function allows you to control how long a cache entry should live before it's automatically invalidated. This is useful for managing cache freshness and memory usage.

Basic Usage​

async function fetchWeatherData(city: string) {
  'use cache';

  // Cache for 30 minutes
  cacheLife('30m');

  const weather = await weatherAPI.getForecast(city);
  return weather;
}

Time Formats​

You can specify the cache duration in multiple formats:

String Format​

async function exampleWithStringTTL() {
  'use cache';

  // Common time units
  cacheLife('5s'); // 5 seconds
  cacheLife('1m'); // 1 minute
  cacheLife('2h'); // 2 hours
  cacheLife('1d'); // 1 day

  return await fetchData();
}

Milliseconds​

async function exampleWithMillisecondsTTL() {
  'use cache';

  // Direct milliseconds
  cacheLife(60000); // 1 minute
  cacheLife(3600000); // 1 hour

  return await fetchData();
}

Example Use Cases​

Short-lived Data​

async function fetchLiveStats() {
  'use cache';

  // Cache for 5 seconds since data changes frequently
  cacheLife('5s');

  return await getLiveStats();
}

Long-lived Data​

async function fetchStaticContent() {
  'use cache';

  // Cache for 1 day since content rarely changes
  cacheLife('1d');

  return await getStaticContent();
}

Dynamic TTL​

async function fetchData(type: 'frequent' | 'rare') {
  'use cache';

  // Set TTL based on data type
  cacheLife(type === 'frequent' ? '5m' : '1h');

  return await getData(type);
}

Best Practices​

  1. Choose Appropriate Duration:

    • Use shorter TTL for frequently changing data
    • Use longer TTL for static content
    • Consider your data update patterns

  2. Balance Freshness and Performance:

    • Don't cache too long if data changes often
    • Don't cache too short if data is static
    • Consider your application's needs

  3. Monitor Cache Behavior:

    • Watch for stale data issues
    • Adjust TTL based on usage patterns
    • Consider memory usage

Common Patterns​

API Data​

async function fetchWeatherData() {
  'use cache';

  // Weather data (changes every 30 minutes)
  cacheLife('30m');

  return await weatherAPI.getForecast();
}

async function fetchNewsData() {
  'use cache';

  // News data (changes every hour)
  cacheLife('1h');

  return await newsAPI.getLatest();
}

async function fetchStaticAPIData() {
  'use cache';

  // Static API data (changes daily)
  cacheLife('1d');

  return await staticAPI.getData();
}

Database Queries​

async function fetchUserPreferences(userId: string) {
  'use cache';

  // User preferences (changes occasionally)
  cacheLife('1h');

  return await db.users.getPreferences(userId);
}

async function fetchGuildSettings(guildId: string) {
  'use cache';

  // Guild settings (changes rarely)
  cacheLife('1d');

  return await db.guilds.getSettings(guildId);
}

async function fetchSystemConfig() {
  'use cache';

  // System configuration (changes very rarely)
  cacheLife('7d');

  return await db.system.getConfig();
}