Class CacheBuilder

corpus/java/training/guava/cache/CacheBuilder.java:147–895

A builder of LoadingCache and Cache instances having any combination of the following features: automatic loading of entries into the cache least-recently-used eviction when a maximum size is exceeded time-based expiration of entries, measured since last access o

 * @since 10.0
 */
@GwtCompatible(emulated = true)
public final class CacheBuilder<K, V> {
  private static final int DEFAULT_INITIAL_CAPACITY = 16;
  private static final int DEFAULT_CONCURRENCY_LEVEL = 4;
  private static final int DEFAULT_EXPIRATION_NANOS = 0;
  private static final int DEFAULT_REFRESH_NANOS = 0;

  static final Supplier<? extends StatsCounter> NULL_STATS_COUNTER =
      Suppliers.ofInstance(
          new StatsCounter() {
            @Override
            public void recordHits(int count) {}

            @Override
            public void recordMisses(int count) {}

            @Override
            public void recordLoadSuccess(long loadTime) {}

            @Override
            public void recordLoadException(long loadTime) {}

            @Override
            public void recordEviction() {}

            @Override
            public CacheStats snapshot() {
              return EMPTY_STATS;
            }
          });
  static final CacheStats EMPTY_STATS = new CacheStats(0, 0, 0, 0, 0, 0);

  static final Supplier<StatsCounter> CACHE_STATS_COUNTER =
      new Supplier<StatsCounter>() {
        @Override
        public StatsCounter get() {
          return new SimpleStatsCounter();
        }
      };

  enum NullListener implements RemovalListener<Object, Object> {
    INSTANCE;

    @Override
    public void onRemoval(RemovalNotification<Object, Object> notification) {}
  }

  enum OneWeigher implements Weigher<Object, Object> {
    INSTANCE;

    @Override
    public int weigh(Object key, Object value) {
      return 1;
    }
  }

  static final Ticker NULL_TICKER =
      new Ticker() {