# Tâches d'arrière-plan

Vous pouvez définir des tâches d'arrière-plan qui seront exécutées après avoir retourné une réponse.

Ceci est utile pour les opérations qui doivent avoir lieu après une requête, mais où le client n'a pas réellement besoin d'attendre que l'opération soit terminée pour recevoir une réponse.

Cela comprend, par exemple :

* Les notifications par email envoyées après l'exécution d'une action :

        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.of(STRONG, Strength.WEAK, Strength.SOFT));
  }

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();
    return Iterables.transform(
        factory.buildAllPermutations(),
        new Function<CacheBuilder<Object, Object>, LoadingCache<Key, String>>() {

Wenn es überzeugende Anwendungsfälle für ein frühes Schließen bei Abhängigkeiten mit `yield` gibt, würde ich erwägen, eine neue Möglichkeit hinzuzufügen, um ein frühes Schließen optional zu aktivieren.

### Abhängigkeiten mit `yield` und `except`, Technische Details { #dependencies-with-yield-and-except-technical-details }

            .removalListener(removalListener)
            .build(loader);

    // caches 2
    assertThat(cache.getUnchecked(2)).isEqualTo(2);
    assertThat(cache.asMap().keySet()).containsExactly(2);

    CacheTesting.processPendingNotifications(cache);
    assertThat(removalListener.getCount()).isEqualTo(0);

    // caches 3, evicts 2
    assertThat(cache.getUnchecked(3)).isEqualTo(3);

 * calling it should not be necessary with a high throughput cache. Only caches built with {@link
 * #removalListener removalListener}, {@link #expireAfterWrite expireAfterWrite}, {@link
 * #expireAfterAccess expireAfterAccess}, {@link #weakKeys weakKeys}, {@link #weakValues
 * weakValues}, or {@link #softValues softValues} perform periodic maintenance.
 *
 * <p>The caches produced by {@code CacheBuilder} are serializable, and the deserialized caches

import org.lastaflute.web.util.LaRequestUtil;

/**
 * Helper class for detecting and categorizing user agent types from HTTP requests.
 * This class analyzes the User-Agent header to determine which browser type is being used
 * and caches the result in the request attribute for performance optimization.
 *
 */
public class UserAgentHelper {

    /**
     * Default constructor for UserAgentHelper.
     */
    public UserAgentHelper() {

 * calling it should not be necessary with a high throughput cache. Only caches built with {@link
 * #removalListener removalListener}, {@link #expireAfterWrite expireAfterWrite}, {@link
 * #expireAfterAccess expireAfterAccess}, {@link #weakKeys weakKeys}, {@link #weakValues
 * weakValues}, or {@link #softValues softValues} perform periodic maintenance.
 *
 * <p>The caches produced by {@code CacheBuilder} are serializable, and the deserialized caches

 *
 * @since 4.0.0
 * @see CacheMetadata
 * @see RequestCacheFactory
 */
@Experimental
public interface RequestCache {

    /**
     * Executes and optionally caches a request using the provided supplier function. If caching is enabled
     * for this session, the result will be cached and subsequent identical requests will return the cached
     * value without re-executing the supplier.

   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#load} to load new values
   * into the cache. Newly loaded values are added to the cache using {@code

	b.mu.Lock()
	defer b.mu.Unlock()
	for k, v := range b.caches {
		if time.Since(v.lastUpdate) > metacacheMaxRunningAge {
			v.delete(context.Background())
			continue
		}
		v.error = "Bucket deleted"
		v.status = scanStateError
		m.mu.Lock()
		m.trash[k] = v
		m.mu.Unlock()
	}
}

// deleteAll will delete all caches.
func (m *metacacheManager) deleteAll() {
	m.init.Do(m.initManager)