/*
* 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.dataset2.lib.kv;
import co.cask.cdap.api.common.Bytes;
import co.cask.cdap.api.dataset.DatasetAdmin;
import co.cask.cdap.api.dataset.DatasetProperties;
import co.cask.cdap.api.dataset.DatasetSpecification;
import co.cask.cdap.api.dataset.lib.AbstractDatasetDefinition;
import co.cask.cdap.api.dataset.module.DatasetDefinitionRegistry;
import co.cask.cdap.api.dataset.module.DatasetModule;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.KeyValue;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTableService;
import com.google.common.base.Throwables;
import com.google.inject.Inject;
import org.iq80.leveldb.DB;
import java.io.IOException;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Simple implementation of leveldb non-tx {@link NoTxKeyValueTable}.
*/
public class LevelDBKVTableDefinition extends AbstractDatasetDefinition<NoTxKeyValueTable, DatasetAdmin> {
@Inject
private LevelDBOrderedTableService service;
public LevelDBKVTableDefinition(String name) {
super(name);
}
@Override
public DatasetSpecification configure(String instanceName, DatasetProperties properties) {
return DatasetSpecification.builder(instanceName, getName())
.properties(properties.getProperties())
.build();
}
@Override
public DatasetAdmin getAdmin(DatasetSpecification spec, ClassLoader classLoader) throws IOException {
return new DatasetAdminImpl(spec.getName(), service);
}
@Override
public NoTxKeyValueTable getDataset(DatasetSpecification spec,
Map<String, String> arguments, ClassLoader classLoader) throws IOException {
return new KVTableImpl(spec.getName(), service);
}
private static final class DatasetAdminImpl implements DatasetAdmin {
private final String tableName;
protected final LevelDBOrderedTableService service;
private DatasetAdminImpl(String tableName, LevelDBOrderedTableService service) throws IOException {
this.tableName = tableName;
this.service = service;
}
@Override
public boolean exists() throws IOException {
try {
service.getTable(tableName);
return true;
} catch (Exception e) {
return false;
}
}
@Override
public void create() throws IOException {
service.ensureTableExists(tableName);
}
@Override
public void drop() throws IOException {
service.dropTable(tableName);
}
@Override
public void truncate() throws IOException {
drop();
create();
}
@Override
public void upgrade() throws IOException {
// no-op
}
@Override
public void close() throws IOException {
// no-op
}
}
private static final class KVTableImpl implements NoTxKeyValueTable {
private static final byte[] DATA_COLFAM = Bytes.toBytes("d");
private static final byte[] DEFAULT_COLUMN = Bytes.toBytes("c");
private final String tableName;
private final LevelDBOrderedTableService service;
public KVTableImpl(String tableName, LevelDBOrderedTableService service) throws IOException {
this.tableName = tableName;
this.service = service;
}
private DB getTable() {
try {
return service.getTable(tableName);
} catch (IOException e) {
throw Throwables.propagate(e);
}
}
@Override
public void put(byte[] key, @Nullable byte[] value) {
if (value == null) {
getTable().delete(createKey(key));
} else {
getTable().put(createKey(key), value);
}
}
@Nullable
@Override
public byte[] get(byte[] key) {
return getTable().get(createKey(key));
}
private static byte[] createKey(byte[] rowKey) {
return new KeyValue(rowKey, DATA_COLFAM, DEFAULT_COLUMN, 1, KeyValue.Type.Put).getKey();
}
@Override
public void close() throws IOException {
// no-op
}
}
/**
* Registers this type as implementation for {@link NoTxKeyValueTable} using class name.
*/
public static final class Module implements DatasetModule {
@Override
public void register(DatasetDefinitionRegistry registry) {
registry.add(new LevelDBKVTableDefinition(NoTxKeyValueTable.class.getName()));
}
}
}