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;
  
  import java.util.Collections;
  import java.util.Set;
  import java.util.function.Predicate;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.RegularAndStaticColumns;
  import org.apache.cassandra.db.WriteContext;
  import org.apache.cassandra.db.filter.RowFilter;
  import org.apache.cassandra.db.lifecycle.ILifecycleTransaction;
  import org.apache.cassandra.db.memtable.Memtable;
  import org.apache.cassandra.index.transactions.IndexTransaction;
  import org.apache.cassandra.io.sstable.Component;
  import org.apache.cassandra.io.sstable.Descriptor;
  import org.apache.cassandra.io.sstable.SSTableFlushObserver;
  import org.apache.cassandra.schema.TableMetadata;
  
  /**
   * An {@link Index.Group} containing a single {@link Index}, to which it just delegates the calls.
   */
  public class SingletonIndexGroup implements Index.Group
  {
      private final Index delegate;
      private final Set<Index> indexes;
  
      protected SingletonIndexGroup(Index delegate)
      {
          this.delegate = delegate;
          this.indexes = Collections.singleton(delegate);
      }
  
      @Override
      public Set<Index> getIndexes()
      {
          return indexes;
      }
  
      public Index getIndex()
      {
          return delegate;
      }
  
      @Override
      public boolean containsIndex(Index index)
      {
          return index.equals(delegate);
      }
  
      @Override
      public Index.Indexer indexerFor(Predicate<Index> indexSelector,
                                      DecoratedKey key,
                                      RegularAndStaticColumns columns,
                                      long nowInSec,
                                      WriteContext ctx,
                                      IndexTransaction.Type transactionType,
                                      Memtable memtable)
      {
          return indexSelector.test(delegate) ? delegate.indexerFor(key, columns, nowInSec, ctx, transactionType, memtable)
                                              : null;
      }
  
      @Override
      public Index.QueryPlan queryPlanFor(RowFilter rowFilter)
      {
          return SingletonIndexQueryPlan.create(delegate, rowFilter);
      }
  
      @Override
      public SSTableFlushObserver getFlushObserver(Descriptor descriptor, ILifecycleTransaction txn, TableMetadata tableMetadata)
      {
          return delegate.getFlushObserver(descriptor, txn);
      }
  
      @Override
      public Set<Component> getComponents()
      {
          return delegate.getComponents();
      }
  }
  