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.index.sai;
  
  import java.util.Collection;
  import java.util.Comparator;
  import java.util.HashSet;
  import java.util.NavigableMap;
  import java.util.Set;
  import java.util.TreeMap;
  import java.util.stream.Collectors;
  
  import org.apache.cassandra.db.ColumnFamilyStore;
  import org.apache.cassandra.index.Index;
  import org.apache.cassandra.index.SecondaryIndexBuilder;
  import org.apache.cassandra.index.sai.disk.format.IndexDescriptor;
  import org.apache.cassandra.io.sstable.SSTableIdFactory;
  import org.apache.cassandra.io.sstable.format.SSTableReader;
  
  class StorageAttachedIndexBuildingSupport implements Index.IndexBuildingSupport
  {
      @Override
      public SecondaryIndexBuilder getIndexBuildTask(ColumnFamilyStore cfs,
                                                     Set<Index> indexes,
                                                     Collection<SSTableReader> sstablesToRebuild,
                                                     boolean isFullRebuild)
      {
          NavigableMap<SSTableReader, Set<StorageAttachedIndex>> sstables = new TreeMap<>(Comparator.comparing(s -> s.descriptor.id, SSTableIdFactory.COMPARATOR));
          StorageAttachedIndexGroup group = StorageAttachedIndexGroup.getIndexGroup(cfs);
  
          assert group != null : "Index group does not exist for table " + cfs.keyspace + '.' + cfs.name;
  
          indexes.stream()
                 .filter((i) -> i instanceof StorageAttachedIndex)
                 .forEach((i) ->
                          {
                              StorageAttachedIndex sai = (StorageAttachedIndex) i;
  
                              // If this is not a full manual index rebuild we can skip SSTables that already have an
                              // attached index. Otherwise, we override any pre-existent index.
                              Collection<SSTableReader> ss = sstablesToRebuild;
                              if (!isFullRebuild)
                              {
                                  ss = sstablesToRebuild.stream()
                                                        .filter(s -> !IndexDescriptor.create(s).isPerColumnIndexBuildComplete(sai.identifier()))
                                                        .collect(Collectors.toList());
                              }
  
                              group.dropIndexSSTables(ss, sai);
  
                              ss.forEach(sstable -> sstables.computeIfAbsent(sstable, ignore -> new HashSet<>()).add(sai));
                          });
  
          return new StorageAttachedIndexBuilder(group, sstables, isFullRebuild, false);
      }
  }
  