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.io.sstable;
  
  import java.io.IOException;
  import java.io.IOError;
  import java.util.Iterator;
  
  import com.google.common.annotations.VisibleForTesting;
  
  import org.apache.cassandra.db.*;
  import org.apache.cassandra.db.rows.*;
  import org.apache.cassandra.io.util.DataInputPlus;
  import org.apache.cassandra.io.util.FileDataInput;
  import org.apache.cassandra.schema.TableMetadata;
  import org.apache.cassandra.utils.AbstractIterator;
  
  /**
   * Utility class to handle deserializing atom from sstables.
   *
   * Note that this is not a full fledged UnfilteredRowIterator. It's also not closeable, it is always
   * the job of the user to close the underlying ressources.
   */
  public abstract class SSTableSimpleIterator extends AbstractIterator<Unfiltered> implements Iterator<Unfiltered>
  {
      final TableMetadata metadata;
      protected final DataInputPlus in;
      protected final DeserializationHelper helper;
  
      private SSTableSimpleIterator(TableMetadata metadata, DataInputPlus in, DeserializationHelper helper)
      {
          this.metadata = metadata;
          this.in = in;
          this.helper = helper;
      }
  
      public static SSTableSimpleIterator create(TableMetadata metadata, DataInputPlus in, SerializationHeader header, DeserializationHelper helper, DeletionTime partitionDeletion)
      {
          return new CurrentFormatIterator(metadata, in, header, helper);
      }
  
      public static SSTableSimpleIterator createTombstoneOnly(TableMetadata metadata, DataInputPlus in, SerializationHeader header, DeserializationHelper helper, DeletionTime partitionDeletion)
      {
          return new CurrentFormatTombstoneIterator(metadata, in, header, helper);
      }
  
      public abstract Row readStaticRow() throws IOException;
  
      private static class CurrentFormatIterator extends SSTableSimpleIterator
      {
          private final SerializationHeader header;
  
          private final Row.Builder builder;
  
          private CurrentFormatIterator(TableMetadata metadata, DataInputPlus in, SerializationHeader header, DeserializationHelper helper)
          {
              super(metadata, in, helper);
              this.header = header;
              this.builder = BTreeRow.sortedBuilder();
          }
  
          public Row readStaticRow() throws IOException
          {
              return header.hasStatic() ? UnfilteredSerializer.serializer.deserializeStaticRow(in, header, helper) : Rows.EMPTY_STATIC_ROW;
          }
  
          protected Unfiltered computeNext()
          {
              try
              {
                  Unfiltered unfiltered = UnfilteredSerializer.serializer.deserialize(in, header, helper, builder);
                  return unfiltered == null ? endOfData() : unfiltered;
              }
              catch (IOException e)
              {
                  throw new IOError(e);
              }
          }
      }
  
      private static class CurrentFormatTombstoneIterator extends SSTableSimpleIterator
      {
          private final SerializationHeader header;
  
          private CurrentFormatTombstoneIterator(TableMetadata metadata, DataInputPlus in, SerializationHeader header, DeserializationHelper helper)
          {
              super(metadata, in, helper);
              this.header = header;
          }
  
          public Row readStaticRow() throws IOException
          {
              if (header.hasStatic())
              {
                  Row staticRow = UnfilteredSerializer.serializer.deserializeStaticRow(in, header, helper);
                  if (!staticRow.deletion().isLive())
                      return BTreeRow.emptyDeletedRow(staticRow.clustering(), staticRow.deletion());
              }
              return Rows.EMPTY_STATIC_ROW;
          }
  
          protected Unfiltered computeNext()
          {
              try
              {
                  Unfiltered unfiltered = UnfilteredSerializer.serializer.deserializeTombstonesOnly((FileDataInput) in, header, helper);
                  return unfiltered == null ? endOfData() : unfiltered;
              }
              catch (IOException e)
              {
                  throw new IOError(e);
              }
          }
      }
  
      @VisibleForTesting
      public static class EmptySSTableSimpleIterator extends SSTableSimpleIterator
      {
          public EmptySSTableSimpleIterator(TableMetadata metadata)
          {
              super(metadata, null, null);
          }
  
          public Row readStaticRow() throws IOException
          {
              return Rows.EMPTY_STATIC_ROW;
          }
  
          protected Unfiltered computeNext()
          {
              return null;
          }
  
          public boolean hasNext()
          {
              return false;
          }
      }
  }
  