bowenli86 commented on a change in pull request #8205: [FLINK-12238] [TABLE/SQL] Support database related operations in GenericHiveMetastoreCatalog and setup flink-connector-hive module URL: https://github.com/apache/flink/pull/8205#discussion_r276919562
########## File path: flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/table/catalog/hive/GenericHiveMetastoreCatalog.java ########## @@ -0,0 +1,259 @@ +/* + * 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.flink.table.catalog.hive; + +import org.apache.flink.table.catalog.CatalogBaseTable; +import org.apache.flink.table.catalog.CatalogDatabase; +import org.apache.flink.table.catalog.GenericCatalogDatabase; +import org.apache.flink.table.catalog.ObjectPath; +import org.apache.flink.table.catalog.ReadableWritableCatalog; +import org.apache.flink.table.catalog.exceptions.CatalogException; +import org.apache.flink.table.catalog.exceptions.DatabaseAlreadyExistException; +import org.apache.flink.table.catalog.exceptions.DatabaseNotEmptyException; +import org.apache.flink.table.catalog.exceptions.DatabaseNotExistException; +import org.apache.flink.table.catalog.exceptions.TableAlreadyExistException; +import org.apache.flink.table.catalog.exceptions.TableNotExistException; +import org.apache.flink.util.StringUtils; + +import org.apache.hadoop.hive.conf.HiveConf; +import org.apache.hadoop.hive.metastore.HiveMetaStoreClient; +import org.apache.hadoop.hive.metastore.IMetaStoreClient; +import org.apache.hadoop.hive.metastore.RetryingMetaStoreClient; +import org.apache.hadoop.hive.metastore.api.AlreadyExistsException; +import org.apache.hadoop.hive.metastore.api.Database; +import org.apache.hadoop.hive.metastore.api.InvalidOperationException; +import org.apache.hadoop.hive.metastore.api.MetaException; +import org.apache.hadoop.hive.metastore.api.NoSuchObjectException; +import org.apache.thrift.TException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.List; + +import static org.apache.flink.util.Preconditions.checkArgument; +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * A catalog that persists all Flink streaming and batch metadata by using Hive metastore as a persistent storage. + */ +public class GenericHiveMetastoreCatalog implements ReadableWritableCatalog { + private static final Logger LOG = LoggerFactory.getLogger(GenericHiveMetastoreCatalog.class); + + public static final String DEFAULT_DB = "default"; + + private final String catalogName; + private final HiveConf hiveConf; + + private String currentDatabase = DEFAULT_DB; + private IMetaStoreClient client; + + public GenericHiveMetastoreCatalog(String catalogName, String hivemetastoreURI) { + this(catalogName, getHiveConf(hivemetastoreURI)); + } + + public GenericHiveMetastoreCatalog(String catalogName, HiveConf hiveConf) { + checkArgument(!StringUtils.isNullOrWhitespaceOnly(catalogName), "catalogName cannot be null or empty"); + this.catalogName = catalogName; + + this.hiveConf = checkNotNull(hiveConf, "hiveConf cannot be null"); + LOG.info("Created GenericHiveMetastoreCatalog '{}'", catalogName); + } + + private static HiveConf getHiveConf(String hiveMetastoreURI) { + checkArgument(!StringUtils.isNullOrWhitespaceOnly(hiveMetastoreURI), "hiveMetastoreURI cannot be null or empty"); + + HiveConf hiveConf = new HiveConf(); + hiveConf.setVar(HiveConf.ConfVars.METASTOREURIS, hiveMetastoreURI); + return hiveConf; + } + + private static IMetaStoreClient getMetastoreClient(HiveConf hiveConf) { + try { + return RetryingMetaStoreClient.getProxy( + hiveConf, + null, + null, + HiveMetaStoreClient.class.getName(), + true); + } catch (MetaException e) { + throw new CatalogException("Failed to create Hive metastore client", e); + } + } + + @Override + public void open() throws CatalogException { + if (client == null) { + client = getMetastoreClient(hiveConf); + LOG.info("Connected to Hive metastore"); + } + } + + @Override + public void close() throws CatalogException { + if (client != null) { + client.close(); + client = null; + LOG.info("Close connection to Hive metastore"); + } + } + + // ------ databases ------ + + @Override + public String getCurrentDatabase() throws CatalogException { + return currentDatabase; + } + + @Override + public void setCurrentDatabase(String databaseName) throws DatabaseNotExistException, CatalogException { + checkArgument(!StringUtils.isNullOrWhitespaceOnly(databaseName)); + + if (!databaseExists(databaseName)) { + throw new DatabaseNotExistException(catalogName, databaseName); + } + + currentDatabase = databaseName; + } + + @Override + public List<String> listDatabases() throws CatalogException { + try { + return client.getAllDatabases(); + } catch (TException e) { + throw new CatalogException( + String.format("Failed to list all databases in %s", catalogName), e); + } + } + + @Override + public CatalogDatabase getDatabase(String databaseName) throws DatabaseNotExistException, CatalogException { + Database hiveDb; + + try { + hiveDb = client.getDatabase(databaseName); + } catch (NoSuchObjectException e) { + throw new DatabaseNotExistException(catalogName, databaseName); + } catch (TException e) { + throw new CatalogException( + String.format("Failed to get database %s from %s", databaseName, catalogName), e); + } + + return new GenericCatalogDatabase(hiveDb.getParameters(), hiveDb.getDescription()); + } + + @Override + public boolean databaseExists(String databaseName) throws CatalogException { + try { + return client.getDatabase(databaseName) != null; Review comment: `client.getDatabase(databaseName) != null;` is used only for the purpose to return a boolean, which will be `true` if the`x != null` gets to run, for this method. `client.getDatabase()` will throw `NoSuchObjectException` if the database doesn't exist, and we catch that to return a `false`. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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