xuefuz commented on a change in pull request #8404: [FLINK-11476][table] Create CatalogManager to manage multiple catalogs URL: https://github.com/apache/flink/pull/8404#discussion_r282981545
########## File path: flink-table/flink-table-planner/src/main/java/org/apache/flink/table/catalog/CatalogCalciteSchema.java ########## @@ -0,0 +1,122 @@ +/* + * 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; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.catalog.exceptions.CatalogException; +import org.apache.flink.table.catalog.exceptions.DatabaseNotExistException; + +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.rel.type.RelProtoDataType; +import org.apache.calcite.schema.Function; +import org.apache.calcite.schema.Schema; +import org.apache.calcite.schema.SchemaPlus; +import org.apache.calcite.schema.SchemaVersion; +import org.apache.calcite.schema.Schemas; +import org.apache.calcite.schema.Table; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Collection; +import java.util.HashSet; +import java.util.Set; + +/** + * A mapping between Flink's catalog and Calcite's schema. This enables to look up and access tables + * in SQL queries without registering tables in advance. Databases are registered as sub-schemas in the schema. + */ +@Internal +public class CatalogCalciteSchema implements Schema { + private static final Logger LOGGER = LoggerFactory.getLogger(CatalogCalciteSchema.class); + + private final String catalogName; + private final Catalog catalog; + + public CatalogCalciteSchema(String catalogName, Catalog catalog) { + this.catalogName = catalogName; + this.catalog = catalog; + } + + /** + * Look up a sub-schema (database) by the given sub-schema name. + * + * @param schemaName name of sub-schema to look up + * @return the sub-schema with a given dbName, or null + */ + @Override + public Schema getSubSchema(String schemaName) { + + if (catalog.databaseExists(schemaName)) { + return new DatabaseCalciteSchema(schemaName, catalog); + } else { + LOGGER.error(String.format("Schema %s does not exist in catalog %s", schemaName, catalogName)); + throw new CatalogException(new DatabaseNotExistException(catalogName, schemaName)); + } + } + + @Override + public Set<String> getSubSchemaNames() { + return new HashSet<>(catalog.listDatabases()); + } + + @Override + public Table getTable(String name) { + return null; + } + + @Override + public Set<String> getTableNames() { + return new HashSet<>(); + } + + @Override + public RelProtoDataType getType(String name) { + return null; Review comment: Returning "null" means no type with the given name is found. I'm not sure if that's desired, but feel free to add an TODO item for this if necessary. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
