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.virtual;
  
  import java.util.function.Consumer;
  
  import org.apache.cassandra.db.ColumnFamilyStore;
  import org.apache.cassandra.db.Keyspace;
  import org.apache.cassandra.db.marshal.LongType;
  import org.apache.cassandra.db.marshal.MapType;
  import org.apache.cassandra.db.marshal.UTF8Type;
  import org.apache.cassandra.db.virtual.AbstractVirtualTable;
  import org.apache.cassandra.db.virtual.SimpleDataSet;
  import org.apache.cassandra.db.virtual.VirtualTable;
  import org.apache.cassandra.dht.LocalPartitioner;
  import org.apache.cassandra.index.sai.StorageAttachedIndex;
  import org.apache.cassandra.index.sai.StorageAttachedIndexGroup;
  import org.apache.cassandra.index.sai.disk.SSTableIndex;
  import org.apache.cassandra.schema.KeyspaceMetadata;
  import org.apache.cassandra.schema.Schema;
  import org.apache.cassandra.schema.TableMetadata;
  
  /**
   * A {@link VirtualTable} providing a system view of SSTable index segment metadata.
   */
  public class SegmentsSystemView extends AbstractVirtualTable
  {
      public static final String NAME = "sai_sstable_index_segments";
  
      public static final String KEYSPACE_NAME = "keyspace_name";
      public static final String INDEX_NAME = "index_name";
      public static final String SSTABLE_NAME = "sstable_name";
      public static final String TABLE_NAME = "table_name";
      public static final String COLUMN_NAME = "column_name";
      public static final String CELL_COUNT = "cell_count";
      public static final String SEGMENT_ROW_ID_OFFSET = "segment_row_id_offset";
      public static final String MIN_SSTABLE_ROW_ID = "min_sstable_row_id";
      public static final String MAX_SSTABLE_ROW_ID = "max_sstable_row_id";
      public static final String START_TOKEN = "start_token";
      public static final String END_TOKEN = "end_token";
      public static final String MIN_TERM = "min_term";
      public static final String MAX_TERM = "max_term";
      public static final String COMPONENT_METADATA = "component_metadata";
  
      public SegmentsSystemView(String keyspace)
      {
          super(TableMetadata.builder(keyspace, NAME)
                             .partitioner(new LocalPartitioner(UTF8Type.instance))
                             .comment("SSTable index segment metadata")
                             .kind(TableMetadata.Kind.VIRTUAL)
                             .addPartitionKeyColumn(KEYSPACE_NAME, UTF8Type.instance)
                             .addClusteringColumn(INDEX_NAME, UTF8Type.instance)
                             .addClusteringColumn(SSTABLE_NAME, UTF8Type.instance)
                             .addClusteringColumn(SEGMENT_ROW_ID_OFFSET, LongType.instance)
                             .addRegularColumn(TABLE_NAME, UTF8Type.instance)
                             .addRegularColumn(COLUMN_NAME, UTF8Type.instance)
                             .addRegularColumn(CELL_COUNT, LongType.instance)
                             .addRegularColumn(MIN_SSTABLE_ROW_ID, LongType.instance)
                             .addRegularColumn(MAX_SSTABLE_ROW_ID, LongType.instance)
                             .addRegularColumn(START_TOKEN, UTF8Type.instance)
                             .addRegularColumn(END_TOKEN, UTF8Type.instance)
                             .addRegularColumn(MIN_TERM, UTF8Type.instance)
                             .addRegularColumn(MAX_TERM, UTF8Type.instance)
                             .addRegularColumn(COMPONENT_METADATA,
                                               MapType.getInstance(UTF8Type.instance,
                                                                   MapType.getInstance(UTF8Type.instance, UTF8Type.instance, false),
                                                                   false))
                             .build());
      }
  
      @Override
      public DataSet data()
      {
          SimpleDataSet dataset = new SimpleDataSet(metadata());
  
          forEachIndex(index -> {
              for (SSTableIndex sstableIndex : index.view())
              {
                  sstableIndex.populateSegmentView(dataset);
              }
          });
  
          return dataset;
      }
  
      private void forEachIndex(Consumer<StorageAttachedIndex> process)
      {
          for (KeyspaceMetadata ks : Schema.instance.getUserKeyspaces())
          {
              Keyspace keyspace = Schema.instance.getKeyspaceInstance(ks.name);
              if (keyspace == null)
                  throw new IllegalStateException("Unknown keyspace " + ks + ". This can occur if the keyspace is being dropped.");
  
              for (ColumnFamilyStore cfs : keyspace.getColumnFamilyStores())
              {
                  StorageAttachedIndexGroup group = StorageAttachedIndexGroup.getIndexGroup(cfs);
  
                  if (group != null)
                      group.getIndexes().stream().map(index -> (StorageAttachedIndex) index).forEach(process);
              }
          }
      }
  }
  