content: /*
   * Copyright [2021-present] [ahoo wang <ahoowang@qq.com> (https://github.com/Ahoo-Wang)].
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *      http://www.apache.org/licenses/LICENSE-2.0
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package me.ahoo.cosid.sharding;
  
  import com.google.common.annotations.Beta;
  import com.google.common.cache.CacheBuilder;
  import com.google.common.cache.CacheLoader;
  import com.google.common.cache.LoadingCache;
  import com.google.common.collect.Range;
  import jakarta.annotation.Nonnull;
  
  import java.util.Collection;
  
  /**
   * Cached Sharding.
   *
   * @author ahoo wang
   */
  @Beta
  public class CachedSharding<T extends Comparable<?>> implements Sharding<T> {
  
      private final Sharding<T> actual;
      private final LoadingCache<Range<T>, Collection<String>> shardingCache;
  
      public CachedSharding(Sharding<T> actual) {
          this.actual = actual;
          shardingCache = CacheBuilder
              .newBuilder()
              .build(new LoadShardingCache());
      }
  
      @Nonnull
      @Override
      public String sharding(T shardingValue) {
          return actual.sharding(shardingValue);
      }
  
      @Nonnull
      @Override
      public Collection<String> sharding(Range<T> shardingValue) {
          return shardingCache.getUnchecked(shardingValue);
      }
  
      @Nonnull
      @Override
      public Collection<String> getEffectiveNodes() {
          return actual.getEffectiveNodes();
      }
  
      private class LoadShardingCache extends CacheLoader<Range<T>, Collection<String>> {
  
          @Override
          public Collection<String> load(@Nonnull Range<T> key) {
              return actual.sharding(key);
          }
      }
  }
  