content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.cassandra.sidecar.utils;
  
  import com.google.common.util.concurrent.MoreExecutors;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.github.benmanes.caffeine.cache.Cache;
  import com.github.benmanes.caffeine.cache.Caffeine;
  import com.github.benmanes.caffeine.cache.RemovalListener;
  import com.github.benmanes.caffeine.cache.Ticker;
  import com.google.inject.Inject;
  import com.google.inject.Singleton;
  import io.vertx.core.Future;
  import org.apache.cassandra.sidecar.config.CacheConfiguration;
  import org.apache.cassandra.sidecar.config.ServiceConfiguration;
  import org.jetbrains.annotations.VisibleForTesting;
  
  /**
   * A factory for caches used in Sidecar
   */
  @Singleton
  public class CacheFactory
  {
      private static final Logger LOGGER = LoggerFactory.getLogger(CacheFactory.class);
  
      private final Cache<SSTableImporter.ImportOptions, Future<Void>> ssTableImportCache;
  
      @Inject
      public CacheFactory(ServiceConfiguration configuration, SSTableImporter ssTableImporter)
      {
          this(configuration, ssTableImporter, Ticker.systemTicker());
      }
  
      @VisibleForTesting
      CacheFactory(ServiceConfiguration configuration, SSTableImporter ssTableImporter, Ticker ticker)
      {
          this.ssTableImportCache = initSSTableImportCache(configuration.sstableImportConfiguration()
                                                                        .cacheConfiguration(),
                                                           ssTableImporter, ticker);
      }
  
      /**
       * @return the cache used for the SSTableImport requests
       */
      public Cache<SSTableImporter.ImportOptions, Future<Void>> ssTableImportCache()
      {
          return ssTableImportCache;
      }
  
      /**
       * Initializes the SSTable Import Cache using the provided {@code configuration} and {@code ticker}
       * for the cache
       *
       * @param configuration   the Cache configuration parameters
       * @param ssTableImporter the reference to the SSTable importer singleton
       * @param ticker          the ticker for the cache
       * @return the initialized cache
       */
      protected Cache<SSTableImporter.ImportOptions, Future<Void>>
      initSSTableImportCache(CacheConfiguration configuration, SSTableImporter ssTableImporter, Ticker ticker)
      {
          long maximumSize = configuration.maximumSize();
          LOGGER.info("Building SSTable Import Cache with expireAfterAccess={}, maxSize={}",
                      configuration.expireAfterAccess(), maximumSize);
          return Caffeine.newBuilder()
                         .ticker(ticker)
                         .executor(MoreExecutors.directExecutor())
                         .expireAfterAccess(configuration.expireAfterAccess().quantity(), configuration.expireAfterAccess().unit())
                         .maximumSize(maximumSize)
                         .recordStats()
                         .removalListener((RemovalListener<SSTableImporter.ImportOptions, Future<Void>>)
                                          (options, result, cause) -> {
                                              LOGGER.debug("Removed entry '{}' with options '{}' from SSTable Import " +
                                                           "Cache and cause {}", result, options, cause);
                                              ssTableImporter.cancelImport(options);
                                          }
                         )
                         .build();
      }
  }
  