hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/metadata/DatanodeSchemaOneDBDefinition.java

/*
 * 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.hadoop.ozone.container.metadata;

import org.apache.hadoop.hdds.StringUtils;
import org.apache.hadoop.hdds.utils.db.DBColumnFamilyDefinition;
import org.apache.hadoop.hdds.utils.db.LongCodec;
import org.apache.hadoop.ozone.container.common.helpers.BlockData;
import org.apache.hadoop.ozone.container.common.helpers.ChunkInfoList;
import org.rocksdb.RocksDB;

/**
 * This class allows support of the schema version one RocksDB layout for
 * datanode, where
 * all data is kept in the same default table. Clients can use this class as
 * if the database is in the new format (which has separate column families for
 * block data, metadata and deleted block IDs), even
 * though all tables map back to the default table in this implementation.
 */
public class DatanodeSchemaOneDBDefinition
        extends AbstractDatanodeDBDefinition {
  // In the underlying database, tables are retrieved by name, and then the
  // codecs/classes are applied on top. By defining different DBDefinitions
  // with different codecs that all map to the default table, clients are
  // unaware they are using the same table for both interpretations of the data.

  // Note that the current RDBStore implementation requires all column
  // families to use the same codec instance for each key/value type.
  public static final DBColumnFamilyDefinition<String, BlockData>
      BLOCK_DATA =
      new DBColumnFamilyDefinition<>(
          StringUtils.bytes2String(RocksDB.DEFAULT_COLUMN_FAMILY),
          String.class,
          new SchemaOneKeyCodec(),
          BlockData.class,
          new BlockDataCodec());

  public static final DBColumnFamilyDefinition<String, Long>
        METADATA =
        new DBColumnFamilyDefinition<>(
            StringUtils.bytes2String(RocksDB.DEFAULT_COLUMN_FAMILY),
            String.class,
            new SchemaOneKeyCodec(),
            Long.class,
            new LongCodec());

  public static final DBColumnFamilyDefinition<String, ChunkInfoList>
        DELETED_BLOCKS =
        new DBColumnFamilyDefinition<>(
            StringUtils.bytes2String(RocksDB.DEFAULT_COLUMN_FAMILY),
            String.class,
            new SchemaOneKeyCodec(),
            ChunkInfoList.class,
            new SchemaOneChunkInfoListCodec());

  protected DatanodeSchemaOneDBDefinition(String dbPath) {
    super(dbPath);
  }

  @Override
  public DBColumnFamilyDefinition<String, BlockData>
      getBlockDataColumnFamily() {
    return BLOCK_DATA;
  }

  @Override
  public DBColumnFamilyDefinition<String, Long> getMetadataColumnFamily() {
    return METADATA;
  }

  @Override
  public DBColumnFamilyDefinition<String, ChunkInfoList>
      getDeletedBlocksColumnFamily() {
    return DELETED_BLOCKS;
  }

  public DBColumnFamilyDefinition[] getColumnFamilies() {
    return new DBColumnFamilyDefinition[] {getBlockDataColumnFamily(),
        getMetadataColumnFamily(), getDeletedBlocksColumnFamily() };
  }
}