sentry-hdfs/src/main/java/org/apache/sentry/hdfs/ExtendedMetastoreClient.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.sentry.hdfs;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.metastore.HiveMetaStoreClient;
import org.apache.hadoop.hive.metastore.api.Database;
import org.apache.hadoop.hive.metastore.api.MetaException;
import org.apache.hadoop.hive.metastore.api.Partition;
import org.apache.hadoop.hive.metastore.api.Table;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ExtendedMetastoreClient implements MetastoreClient {
  
  private static Logger LOG = LoggerFactory.getLogger(ExtendedMetastoreClient.class);

  private HiveMetaStoreClient client;
  private final HiveConf hiveConf;
  public ExtendedMetastoreClient(HiveConf hiveConf) {
    this.hiveConf = hiveConf;
  }

  @Override
  public List<Database> getAllDatabases() {
    List<Database> retList = new ArrayList<Database>();
    HiveMetaStoreClient client = getClient();
    if (client != null) {
      try {
        for (String dbName : client.getAllDatabases()) {
          retList.add(client.getDatabase(dbName));
        }
      } catch (Exception e) {
        LOG.error("Could not get All Databases !!", e);
      }
    }
    return retList;
  }

  @Override
  public List<Table> getAllTablesOfDatabase(Database db) {
    List<Table> retList = new ArrayList<Table>();
    HiveMetaStoreClient client = getClient();
    if (client != null) {
      try {
        for (String tblName : client.getAllTables(db.getName())) {
          retList.add(client.getTable(db.getName(), tblName));
        }
      } catch (Exception e) {
        LOG.error(String.format(
            "Could not get Tables for '%s' !!", db.getName()), e);
      }
    }
    return retList;
  }

  @Override
  public List<Partition> listAllPartitions(Database db, Table tbl) {
    HiveMetaStoreClient client = getClient();
    if (client != null) {
      try {
        return client.listPartitions(db.getName(), tbl.getTableName(), Short.MAX_VALUE);
      } catch (Exception e) {
        LOG.error(String.format(
            "Could not get partitions for '%s'.'%s' !!", db.getName(),
            tbl.getTableName()), e);
      }
    }
    return new LinkedList<Partition>();
  }

  private HiveMetaStoreClient getClient() {
    if (client == null) {
      try {
        client = new HiveMetaStoreClient(hiveConf);
        return client;
      } catch (MetaException e) {
        client = null;
        LOG.error("Could not create metastore client !!", e);
        return null;
      }
    } else {
      return client;
    }
  }
}