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.ArrayList;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import org.apache.bookkeeper.client.api.LedgerMetadata;
  import org.apache.bookkeeper.net.BookieId;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  class EnsembleUtils {
      private static final Logger LOG = LoggerFactory.getLogger(EnsembleUtils.class);
  
      static List<BookieId> replaceBookiesInEnsemble(BookieWatcher bookieWatcher,
                                                                LedgerMetadata metadata,
                                                                List<BookieId> oldEnsemble,
                                                                Map<Integer, BookieId> failedBookies,
                                                                String logContext)
              throws BKException.BKNotEnoughBookiesException {
          List<BookieId> newEnsemble = new ArrayList<>(oldEnsemble);
  
          int ensembleSize = metadata.getEnsembleSize();
          int writeQ = metadata.getWriteQuorumSize();
          int ackQ = metadata.getAckQuorumSize();
          Map<String, byte[]> customMetadata = metadata.getCustomMetadata();
  
          Set<BookieId> exclude = new HashSet<>(failedBookies.values());
  
          int replaced = 0;
          for (Map.Entry<Integer, BookieId> entry : failedBookies.entrySet()) {
              int idx = entry.getKey();
              BookieId addr = entry.getValue();
              if (LOG.isDebugEnabled()) {
                  LOG.debug("{} replacing bookie: {} index: {}", logContext, addr, idx);
              }
  
              if (!newEnsemble.get(idx).equals(addr)) {
                  if (LOG.isDebugEnabled()) {
                      LOG.debug("{} Not changing failed bookie {} at index {}, already changed to {}",
                                logContext, addr, idx, newEnsemble.get(idx));
                  }
                  continue;
              }
              try {
                  BookieId newBookie = bookieWatcher.replaceBookie(
                          ensembleSize, writeQ, ackQ, customMetadata, newEnsemble, idx, exclude);
                  newEnsemble.set(idx, newBookie);
  
                  replaced++;
              } catch (BKException.BKNotEnoughBookiesException e) {
                  // if there is no bookie replaced, we throw not enough bookie exception
                  if (replaced <= 0) {
                      throw e;
                  } else {
                      break;
                  }
              }
          }
          return newEnsemble;
      }
  
      static Set<Integer> diffEnsemble(List<BookieId> e1,
                                       List<BookieId> e2) {
          checkArgument(e1.size() == e2.size(), "Ensembles must be of same size");
          Set<Integer> diff = new HashSet<>();
          for (int i = 0; i < e1.size(); i++) {
              if (!e1.get(i).equals(e2.get(i))) {
                  diff.add(i);
              }
          }
          return diff;
      }
  }
  