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;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  import com.google.common.collect.ImmutableList;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.db.PartitionPosition;
  import org.apache.cassandra.db.virtual.SimpleDataSet;
  import org.apache.cassandra.dht.AbstractBounds;
  import org.apache.cassandra.dht.Token;
  import org.apache.cassandra.index.sai.QueryContext;
  import org.apache.cassandra.index.sai.SSTableContext;
  import org.apache.cassandra.index.sai.StorageAttachedIndex;
  import org.apache.cassandra.index.sai.disk.SSTableIndex;
  import org.apache.cassandra.index.sai.disk.v1.segment.Segment;
  import org.apache.cassandra.index.sai.disk.v1.segment.SegmentMetadata;
  import org.apache.cassandra.index.sai.iterators.KeyRangeIterator;
  import org.apache.cassandra.index.sai.iterators.KeyRangeUnionIterator;
  import org.apache.cassandra.index.sai.plan.Expression;
  import org.apache.cassandra.index.sai.utils.PrimaryKey;
  import org.apache.cassandra.io.sstable.format.SSTableReader;
  import org.apache.cassandra.io.util.FileUtils;
  import org.apache.cassandra.utils.Throwables;
  
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.CELL_COUNT;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.COLUMN_NAME;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.COMPONENT_METADATA;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.END_TOKEN;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.MAX_SSTABLE_ROW_ID;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.MAX_TERM;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.MIN_SSTABLE_ROW_ID;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.MIN_TERM;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.START_TOKEN;
  import static org.apache.cassandra.index.sai.virtual.SegmentsSystemView.TABLE_NAME;
  
  /**
   * A version specific implementation of the {@link SSTableIndex} where the
   * index is segmented
   */
  public class V1SSTableIndex extends SSTableIndex
  {
      private final ImmutableList<Segment> segments;
      private final List<SegmentMetadata> metadatas;
      private final AbstractBounds<PartitionPosition> bounds;
      private final ByteBuffer minTerm;
      private final ByteBuffer maxTerm;
      private final long minSSTableRowId, maxSSTableRowId;
      private final long numRows;
  
      private PerColumnIndexFiles indexFiles;
  
      public V1SSTableIndex(SSTableContext sstableContext, StorageAttachedIndex index)
      {
          super(sstableContext, index);
  
          try
          {
              this.indexFiles = new PerColumnIndexFiles(sstableContext.indexDescriptor, indexTermType, indexIdentifier);
  
              ImmutableList.Builder<Segment> segmentsBuilder = ImmutableList.builder();
  
              final MetadataSource source = MetadataSource.loadColumnMetadata(sstableContext.indexDescriptor, indexIdentifier);
  
              metadatas = SegmentMetadata.load(source, sstableContext.indexDescriptor.primaryKeyFactory);
  
              for (SegmentMetadata metadata : metadatas)
              {
                  segmentsBuilder.add(new Segment(index, sstableContext, indexFiles, metadata));
              }
  
              segments = segmentsBuilder.build();
              assert !segments.isEmpty();
  
              DecoratedKey minKey = metadatas.get(0).minKey.partitionKey();
              DecoratedKey maxKey = metadatas.get(metadatas.size() - 1).maxKey.partitionKey();
  
              this.bounds = AbstractBounds.bounds(minKey, true, maxKey, true);
  
              this.minTerm = metadatas.stream().map(m -> m.minTerm).min(indexTermType.comparator()).orElse(null);
              this.maxTerm = metadatas.stream().map(m -> m.maxTerm).max(indexTermType.comparator()).orElse(null);
  
              this.numRows = metadatas.stream().mapToLong(m -> m.numRows).sum();
  
              this.minSSTableRowId = metadatas.get(0).minSSTableRowId;
              this.maxSSTableRowId = metadatas.get(metadatas.size() - 1).maxSSTableRowId;
          }
          catch (Throwable t)
          {
              FileUtils.closeQuietly(indexFiles);
              // Close the shared copy we just created in the superclass constructor:
              FileUtils.closeQuietly(super.sstableContext);
              throw Throwables.unchecked(t);
          }
      }
  
      @Override
      public long indexFileCacheSize()
      {
          return segments.stream().mapToLong(Segment::indexFileCacheSize).sum();
      }
  
      @Override
      public long getRowCount()
      {
          return numRows;
      }
  
      @Override
      public long minSSTableRowId()
      {
          return minSSTableRowId;
      }
  
      @Override
      public long maxSSTableRowId()
      {
          return maxSSTableRowId;
      }
  
      @Override
      public ByteBuffer minTerm()
      {
          return minTerm;
      }
  
      @Override
      public ByteBuffer maxTerm()
      {
          return maxTerm;
      }
  
      @Override
      public AbstractBounds<PartitionPosition> bounds()
      {
          return bounds;
      }
  
      @Override
      public List<KeyRangeIterator> search(Expression expression,
                                           AbstractBounds<PartitionPosition> keyRange,
                                           QueryContext context) throws IOException
      {
          List<KeyRangeIterator> segmentIterators = new ArrayList<>();
  
          for (Segment segment : segments)
          {
              if (segment.intersects(keyRange))
              {
                  segmentIterators.add(segment.search(expression, keyRange, context));
              }
          }
  
          return segmentIterators;
      }
  
      @Override
      public KeyRangeIterator limitToTopKResults(QueryContext context, List<PrimaryKey> primaryKeys, Expression expression) throws IOException
      {
          KeyRangeUnionIterator.Builder unionIteratorBuilder = KeyRangeUnionIterator.builder(segments.size());
          for (Segment segment : segments)
              unionIteratorBuilder.add(segment.limitToTopKResults(context, primaryKeys, expression));
  
          return unionIteratorBuilder.build();
      }
  
      @Override
      public void populateSegmentView(SimpleDataSet dataset)
      {
          SSTableReader sstable = getSSTable();
          Token.TokenFactory tokenFactory = sstable.metadata().partitioner.getTokenFactory();
  
          for (SegmentMetadata metadata : metadatas)
          {
              dataset.row(sstable.metadata().keyspace, indexIdentifier.indexName, sstable.getFilename(), metadata.rowIdOffset)
                     .column(TABLE_NAME, sstable.descriptor.cfname)
                     .column(COLUMN_NAME, indexTermType.columnName())
                     .column(CELL_COUNT, metadata.numRows)
                     .column(MIN_SSTABLE_ROW_ID, metadata.minSSTableRowId)
                     .column(MAX_SSTABLE_ROW_ID, metadata.maxSSTableRowId)
                     .column(START_TOKEN, tokenFactory.toString(metadata.minKey.token()))
                     .column(END_TOKEN, tokenFactory.toString(metadata.maxKey.token()))
                     .column(MIN_TERM, indexTermType.indexType().getSerializer().deserialize(metadata.minTerm).toString())
                     .column(MAX_TERM, indexTermType.indexType().getSerializer().deserialize(metadata.maxTerm).toString())
                     .column(COMPONENT_METADATA, metadata.componentMetadatas.asMap());
          }
      }
  
      @Override
      protected void internalRelease()
      {
          FileUtils.closeQuietly(indexFiles);
          FileUtils.closeQuietly(segments);
      }
  }
  