/**
* Copyright 2013 Cloudera 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 com.cloudera.cdk.data.hcatalog;
import com.cloudera.cdk.data.DatasetDescriptor;
import com.cloudera.cdk.data.DatasetExistsException;
import com.cloudera.cdk.data.MetadataProviderException;
import com.google.common.base.Preconditions;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.metastore.TableType;
import org.apache.hadoop.hive.ql.metadata.Table;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class HCatalogManagedMetadataProvider extends HCatalogMetadataProvider {
private static final Logger logger = LoggerFactory
.getLogger(HCatalogManagedMetadataProvider.class);
public HCatalogManagedMetadataProvider(Configuration conf) {
super(conf);
}
@Override
public DatasetDescriptor load(String name) {
Preconditions.checkArgument(name != null, "Name cannot be null");
final Table table = hcat.getTable(HiveUtils.DEFAULT_DB, name);
if (!TableType.MANAGED_TABLE.equals(table.getTableType())) {
throw new MetadataProviderException("Table is not managed");
}
return HiveUtils.descriptorForTable(conf, table);
}
@Override
public DatasetDescriptor create(String name, DatasetDescriptor descriptor) {
Preconditions.checkArgument(name != null, "Name cannot be null");
Preconditions.checkArgument(descriptor != null,
"Descriptor cannot be null");
if (exists(name)) {
throw new DatasetExistsException(
"Metadata already exists for dataset:" + name);
}
logger.info("Creating a managed Hive table named: " + name);
// construct the table metadata from a descriptor
final Table table = HiveUtils.tableForDescriptor(
name, descriptor, false /* managed table */);
// create it
hcat.createTable(table);
// load the created table to get the data location
final Table newTable = hcat.getTable(HiveUtils.DEFAULT_DB, name);
return new DatasetDescriptor.Builder(descriptor)
.location(newTable.getDataLocation())
.build();
}
}