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.disk.v1.segment;
  
  import java.io.IOException;
  import java.lang.invoke.MethodHandles;
  
  import com.google.common.base.MoreObjects;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.cassandra.db.PartitionPosition;
  import org.apache.cassandra.dht.AbstractBounds;
  import org.apache.cassandra.index.sai.QueryContext;
  import org.apache.cassandra.index.sai.StorageAttachedIndex;
  import org.apache.cassandra.index.sai.disk.PrimaryKeyMap;
  import org.apache.cassandra.index.sai.disk.format.IndexComponent;
  import org.apache.cassandra.index.sai.disk.v1.PerColumnIndexFiles;
  import org.apache.cassandra.index.sai.disk.v1.bbtree.BlockBalancedTreeReader;
  import org.apache.cassandra.index.sai.iterators.KeyRangeIterator;
  import org.apache.cassandra.index.sai.metrics.MulticastQueryEventListeners;
  import org.apache.cassandra.index.sai.metrics.QueryEventListener;
  import org.apache.cassandra.index.sai.plan.Expression;
  import org.apache.lucene.index.CorruptIndexException;
  
  import static org.apache.cassandra.index.sai.disk.v1.bbtree.BlockBalancedTreeQueries.balancedTreeQueryFrom;
  
  /**
   * Executes {@link Expression}s against the balanced tree for an individual index segment.
   */
  public class NumericIndexSegmentSearcher extends IndexSegmentSearcher
  {
      private static final Logger logger = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
  
      private final BlockBalancedTreeReader treeReader;
      private final QueryEventListener.BalancedTreeEventListener perColumnEventListener;
  
      NumericIndexSegmentSearcher(PrimaryKeyMap.Factory primaryKeyMapFactory,
                                  PerColumnIndexFiles perIndexFiles,
                                  SegmentMetadata segmentMetadata,
                                  StorageAttachedIndex index) throws IOException
      {
          super(primaryKeyMapFactory, perIndexFiles, segmentMetadata, index);
  
          final long treePosition = metadata.getIndexRoot(IndexComponent.BALANCED_TREE);
          if (treePosition < 0)
              throw new CorruptIndexException(index.identifier().logMessage("The tree position is less than zero."), IndexComponent.BALANCED_TREE.name);
          final long postingsPosition = metadata.getIndexRoot(IndexComponent.POSTING_LISTS);
          if (postingsPosition < 0)
              throw new CorruptIndexException(index.identifier().logMessage("The postings position is less than zero."), IndexComponent.BALANCED_TREE.name);
  
          treeReader = new BlockBalancedTreeReader(index.identifier(),
                                                   indexFiles.balancedTree(),
                                                   treePosition,
                                                   indexFiles.postingLists(),
                                                   postingsPosition);
          perColumnEventListener = (QueryEventListener.BalancedTreeEventListener)index.columnQueryMetrics();
      }
  
      @Override
      public long indexFileCacheSize()
      {
          return treeReader.memoryUsage();
      }
  
      @Override
      public KeyRangeIterator search(Expression exp, AbstractBounds<PartitionPosition> keyRange, QueryContext context) throws IOException
      {
          if (logger.isTraceEnabled())
              logger.trace(index.identifier().logMessage("Searching on expression '{}'..."), exp);
  
          if (exp.getIndexOperator().isEqualityOrRange())
          {
              final BlockBalancedTreeReader.IntersectVisitor query = balancedTreeQueryFrom(exp, treeReader.getBytesPerValue());
              QueryEventListener.BalancedTreeEventListener listener = MulticastQueryEventListeners.of(context, perColumnEventListener);
              return toPrimaryKeyIterator(treeReader.intersect(query, listener, context), context);
          }
          else
          {
              throw new IllegalArgumentException(index.identifier().logMessage("Unsupported expression during index query: " + exp));
          }
      }
  
      @Override
      public String toString()
      {
          return MoreObjects.toStringHelper(this)
                            .add("index", index)
                            .add("count", treeReader.getPointCount())
                            .add("bytesPerValue", treeReader.getBytesPerValue())
                            .toString();
      }
  
      @Override
      public void close()
      {
          treeReader.close();
      }
  }
  