/** Discards all entries in the cache. */
  void invalidateAll();

  /** Returns the approximate number of entries in this cache. */
  long size();

  /**
   * Returns a current snapshot of this cache's cumulative statistics, or a set of default values if
   * the cache is not recording statistics. All statistics begin at zero and never decrease over the
   * lifetime of the cache.
   *

 * the License.
 */

package com.google.common.cache;

import static com.google.common.cache.TestingCacheLoaders.bulkLoader;
import static com.google.common.cache.TestingCacheLoaders.constantLoader;
import static com.google.common.cache.TestingCacheLoaders.errorLoader;
import static com.google.common.cache.TestingCacheLoaders.exceptionLoader;
import static com.google.common.cache.TestingCacheLoaders.identityLoader;

    getAll(cache, asList(6, 8));
    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(1, 3, 6, 8);

    // get fails to save 1, put saves 3
    cache.asMap().put(3, -3);
    getAll(cache, asList(1));
    CacheTesting.drainRecencyQueues(cache);
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(6, 8, 3);

 * the License.
 */

package com.google.common.cache;

import static com.google.common.cache.CacheTesting.checkEmpty;
import static com.google.common.cache.TestingCacheLoaders.constantLoader;
import static com.google.common.cache.TestingCacheLoaders.exceptionLoader;
import static com.google.common.cache.TestingRemovalListeners.queuingRemovalListener;
import static com.google.common.truth.Truth.assertThat;

   * Cache.asMap().putIfAbsent} after loading has completed; if another value was associated with
   * {@code key} while the new value was loading then a removal notification will be sent for the
   * new value.
   *
   * <p>If the cache loader associated with this cache is known not to throw checked exceptions,
   * then prefer {@link #getUnchecked} over this method.
   *

import junit.framework.TestCase;

/**
 * Unit test for {@link ForwardingCache}.
 *
 * @author Charles Fry
 */
public class ForwardingCacheTest extends TestCase {
  private Cache<String, Boolean> forward;
  private Cache<String, Boolean> mock;

  @SuppressWarnings({"unchecked", "DoNotMock"}) // mock
  @Override
  public void setUp() throws Exception {
    super.setUp();
    /*

    LocalCache<Object, Object> cache =
        new LocalCache<>(CacheBuilder.newBuilder().concurrencyLevel(1), null);
    segment = cache.segments[0];
    chain = null;
    for (int i = 0; i < length; i++) {
      Object key = new Object();
      // TODO(b/145386688): This access should be guarded by 'this.segment', which is not currently
      // held
      chain = segment.newEntry(key, cache.hash(key), chain);
      if (i == 0) {

 * limitations under the License.
 */

package com.google.common.cache;

import static com.google.common.base.MoreObjects.firstNonNull;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import com.google.common.base.Equivalence;
import com.google.common.base.Ticker;
import com.google.common.cache.AbstractCache.StatsCounter;

 * the License.
 */

package com.google.common.cache;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ExecutionException;

/**
 * A cache which forwards all its method calls to another cache. Subclasses should override one or

   * @param function the function to be used for loading values; must never return {@code null}
   * @return a cache loader that loads values by passing each key to {@code function}
   */
  public static <K, V> CacheLoader<K, V> from(Function<K, V> function) {
    return new FunctionToCacheLoader<>(function);
  }

  /**
   * Returns a cache loader based on an <i>existing</i> supplier instance. Note that there's no need