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.internal.composites;
  
  import java.nio.ByteBuffer;
  
  import org.apache.cassandra.db.*;
  import org.apache.cassandra.db.marshal.CompositeType;
  import org.apache.cassandra.db.rows.CellPath;
  import org.apache.cassandra.db.rows.Row;
  import org.apache.cassandra.index.internal.CassandraIndex;
  import org.apache.cassandra.index.internal.IndexEntry;
  import org.apache.cassandra.schema.IndexMetadata;
  
  /**
   * Index on a PARTITION_KEY column definition.
   *
   * This suppose a composite row key:
   *   rk = rk_0 ... rk_n
   *
   * The corresponding index entry will be:
   *   - index row key will be rk_i (where i == columnDef.componentIndex)
   *   - cell name will be: rk ck
   *     where rk is the fully partition key and ck the clustering keys of the
   *     original cell names (thus excluding the last column name as we want to refer to
   *     the whole CQL3 row, not just the cell itself)
   *
   * Note that contrarily to other type of index, we repeat the indexed value in
   * the index cell name (we use the whole partition key). The reason is that we
   * want to order the index cell name by partitioner first, and skipping a part
   * of the row key would change the order.
   */
  public class PartitionKeyIndex extends CassandraIndex
  {
      private final boolean enforceStrictLiveness;
      public PartitionKeyIndex(ColumnFamilyStore baseCfs, IndexMetadata indexDef)
      {
          super(baseCfs, indexDef);
          this.enforceStrictLiveness = baseCfs.metadata.get().enforceStrictLiveness();
      }
  
      public ByteBuffer getIndexedValue(ByteBuffer partitionKey,
                                        Clustering<?> clustering,
                                        CellPath path,
                                        ByteBuffer cellValue)
      {
          CompositeType keyComparator = (CompositeType)baseCfs.metadata().partitionKeyType;
          ByteBuffer[] components = keyComparator.split(partitionKey);
          return components[indexedColumn.position()];
      }
  
      public <T> CBuilder buildIndexClusteringPrefix(ByteBuffer partitionKey,
                                                     ClusteringPrefix<T> prefix,
                                                     CellPath path)
      {
          CBuilder builder = CBuilder.create(getIndexComparator());
          builder.add(partitionKey);
          for (int i = 0; i < prefix.size(); i++)
              builder.add(prefix.get(i), prefix.accessor());
          return builder;
      }
  
      public IndexEntry decodeEntry(DecoratedKey indexedValue, Row indexEntry)
      {
          int ckCount = baseCfs.metadata().clusteringColumns().size();
          Clustering<?> clustering = indexEntry.clustering();
          CBuilder builder = CBuilder.create(baseCfs.getComparator());
          for (int i = 0; i < ckCount; i++)
              builder.add(clustering, i + 1);
  
          return new IndexEntry(indexedValue,
                                clustering,
                                indexEntry.primaryKeyLivenessInfo().timestamp(),
                                clustering.bufferAt(0),
                                builder.build());
      }
  
      public boolean isStale(Row data, ByteBuffer indexValue, long nowInSec)
      {
          return !data.hasLiveData(nowInSec, enforceStrictLiveness);
      }
  }
  