/*
* Copyright © 2014 Cask Data, Inc.
*
* Licensed 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 co.cask.cdap.data2.transaction.stream.leveldb;
import co.cask.cdap.common.conf.CConfiguration;
import co.cask.cdap.data.Namespace;
import co.cask.cdap.data2.datafabric.DefaultDatasetNamespace;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTableCore;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTableService;
import co.cask.cdap.data2.transaction.queue.QueueConstants;
import co.cask.cdap.data2.transaction.stream.StreamConfig;
import co.cask.cdap.data2.transaction.stream.StreamConsumerStateStore;
import co.cask.cdap.data2.transaction.stream.StreamConsumerStateStoreFactory;
import com.google.inject.Inject;
import java.io.IOException;
/**
* Factory for creating {@link StreamConsumerStateStore} in level db.
*/
public final class LevelDBStreamConsumerStateStoreFactory implements StreamConsumerStateStoreFactory {
private final LevelDBOrderedTableService tableService;
private final String tableName;
private LevelDBOrderedTableCore coreTable;
@Inject
LevelDBStreamConsumerStateStoreFactory(CConfiguration conf, LevelDBOrderedTableService tableService) {
this.tableService = tableService;
this.tableName = new DefaultDatasetNamespace(conf, Namespace.SYSTEM)
.namespace(QueueConstants.STREAM_TABLE_PREFIX + ".state.store");
}
@Override
public synchronized StreamConsumerStateStore create(StreamConfig streamConfig) throws IOException {
if (coreTable == null) {
tableService.ensureTableExists(tableName);
coreTable = new LevelDBOrderedTableCore(tableName, tableService);
}
return new LevelDBStreamConsumerStateStore(streamConfig, coreTable);
}
@Override
public synchronized void dropAll() throws IOException {
coreTable = null;
tableService.dropTable(tableName);
}
}