/**
* 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 org.kitesdk.data.spi.hive;
import com.google.common.base.Preconditions;
import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hive.metastore.api.Table;
import org.kitesdk.data.DatasetDescriptor;
import org.kitesdk.data.DatasetExistsException;
import org.kitesdk.data.DatasetIOException;
import org.kitesdk.data.spi.Compatibility;
import org.kitesdk.data.spi.filesystem.FileSystemUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class HiveExternalMetadataProvider extends HiveAbstractMetadataProvider {
private static final Logger LOG = LoggerFactory
.getLogger(HiveExternalMetadataProvider.class);
private final Path rootDirectory;
private final FileSystem rootFileSystem;
public HiveExternalMetadataProvider(Configuration conf, Path rootDirectory) {
super(conf);
Preconditions.checkNotNull(rootDirectory, "Root cannot be null");
try {
this.rootFileSystem = rootDirectory.getFileSystem(conf);
this.rootDirectory = rootFileSystem.makeQualified(rootDirectory);
} catch (IOException ex) {
throw new DatasetIOException("Could not get FileSystem for root path", ex);
}
}
@Override
public DatasetDescriptor create(String namespace, String name, DatasetDescriptor descriptor) {
Compatibility.checkDatasetName(namespace, name);
Compatibility.checkDescriptor(descriptor);
String resolved = resolveNamespace(
namespace, name, descriptor.getLocation());
if (resolved != null) {
if (resolved.equals(namespace)) {
// the requested dataset already exists
throw new DatasetExistsException(
"Metadata already exists for dataset: " + namespace + "." + name);
} else {
// replacing old default.name table
LOG.warn("Creating table {}.{} for {}: replaces default.{}",
new Object[]{
namespace, name, pathForDataset(namespace, name), name});
// validate that the new metadata can read the existing data
Compatibility.checkUpdate(load(resolved, name), descriptor);
}
}
LOG.info("Creating an external Hive table: {}.{}", namespace, name);
DatasetDescriptor newDescriptor = descriptor;
if (descriptor.getLocation() == null) {
// create a new descriptor with the dataset's location
newDescriptor = new DatasetDescriptor.Builder(descriptor)
.location(pathForDataset(namespace, name))
.build();
}
// create the data directory first so it is owned by the current user, not Hive
FileSystemUtil.ensureLocationExists(newDescriptor, conf);
// this object will be the table metadata
Table table = HiveUtils.tableForDescriptor(
namespace, name, newDescriptor, true /* external table */);
// assign the location of the the table
getMetaStoreUtil().createTable(table);
return newDescriptor;
}
@Override
protected URI expectedLocation(String namespace, String name) {
return pathForDataset(namespace, name).toUri();
}
private Path pathForDataset(String namespace, String name) {
Preconditions.checkState(rootDirectory != null,
"Dataset repository root directory can not be null");
return rootFileSystem.makeQualified(
HiveUtils.pathForDataset(rootDirectory, namespace, name));
}
}