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.bookkeeper.client;
  
  import static com.google.common.base.Preconditions.checkArgument;
  
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.SortedMap;
  import org.apache.bookkeeper.client.api.LedgerMetadata;
  import org.apache.bookkeeper.net.BookieId;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Utilities for working with ledger metadata.
   */
  public class LedgerMetadataUtils {
      static final Logger LOG = LoggerFactory.getLogger(LedgerMetadataUtils.class);
  
      static List<BookieId> getCurrentEnsemble(LedgerMetadata metadata) {
          return getLastEnsembleValue(metadata);
      }
  
      /**
       * the entry id greater than the given entry-id at which the next ensemble change takes
       * place.
       *
       * @param entryId
       * @return the entry id of the next ensemble change (-1 if no further ensemble changes)
       */
      static long getNextEnsembleChange(LedgerMetadata metadata, long entryId) {
          SortedMap<Long, ? extends List<BookieId>> tailMap = metadata.getAllEnsembles().tailMap(entryId + 1);
  
          if (tailMap.isEmpty()) {
              return -1;
          } else {
              return tailMap.firstKey();
          }
      }
  
      static Set<BookieId> getBookiesInThisLedger(LedgerMetadata metadata) {
          Set<BookieId> bookies = new HashSet<BookieId>();
          for (List<BookieId> ensemble : metadata.getAllEnsembles().values()) {
              bookies.addAll(ensemble);
          }
          return bookies;
      }
  
      static List<BookieId> getLastEnsembleValue(LedgerMetadata metadata) {
          checkArgument(!metadata.getAllEnsembles().isEmpty(), "Metadata should never be created with no ensembles");
          return metadata.getAllEnsembles().lastEntry().getValue();
      }
  
      static Long getLastEnsembleKey(LedgerMetadata metadata) {
          checkArgument(!metadata.getAllEnsembles().isEmpty(), "Metadata should never be created with no ensembles");
          return metadata.getAllEnsembles().lastKey();
      }
  
      public static boolean shouldStoreCtime(LedgerMetadata metadata) {
          return metadata instanceof LedgerMetadataImpl && ((LedgerMetadataImpl) metadata).shouldStoreCtime();
      }
  }
  