bowenli86 commented on a change in pull request #8214: [FLINK-11476] [table] Create CatalogManager to manage multiple catalogs and encapsulate Calcite schema URL: https://github.com/apache/flink/pull/8214#discussion_r277777987
########## File path: flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/catalog/CatalogCalciteSchema.java ########## @@ -0,0 +1,248 @@ +/* + * 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.flink.table.catalog.exceptions.TableNotExistException; + +import org.apache.calcite.linq4j.tree.Expression; +import org.apache.calcite.rel.type.RelDataType; +import org.apache.calcite.rel.type.RelDataTypeFactory; +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.apache.calcite.sql.type.SqlTypeName; +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. + * This mapping is modeled as a strict two-level reference structure for Flink in Calcite, + * the full path of tables and views is of format [catalog_name].[db_name].[meta-object_name]. + */ +@Internal +public class CatalogCalciteSchema implements Schema { + private static final Logger LOGGER = LoggerFactory.getLogger(CatalogCalciteSchema.class); + + private final String catalogName; + private final ReadableCatalog catalog; + + public CatalogCalciteSchema(String catalogName, ReadableCatalog catalog) { + this.catalogName = catalogName; + this.catalog = catalog; + } + + /** + * Looks up a sub-schema (database) by the given sub-schema name. + * + * @param schemaName Name of sub-schema to look up. + * @return 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) { + throw new UnsupportedOperationException( + "CatalogCalciteSchema does not support getTable()"); + } + + @Override + public Set<String> getTableNames() { + throw new UnsupportedOperationException( + "CatalogCalciteSchema does not support getTableNames()"); + } + + @Override + public RelProtoDataType getType(String name) { + return new RelProtoDataType() { + @Override + public RelDataType apply(RelDataTypeFactory relDataTypeFactory) { + return relDataTypeFactory.createSqlType(SqlTypeName.valueOf(name)); + } + }; + } + + @Override + public Set<String> getTypeNames() { + return new HashSet<>(); + } + + @Override + public Collection<Function> getFunctions(String s) { + return new HashSet<>(); + } + + @Override + public Set<String> getFunctionNames() { + return new HashSet<>(); + } + + @Override + public Expression getExpression(SchemaPlus parentSchema, String name) { + return Schemas.subSchemaExpression(parentSchema, name, getClass()); + } + + @Override + public boolean isMutable() { + return true; + } + + @Override + public Schema snapshot(SchemaVersion schemaVersion) { + return this; + } + + /** + * Register a ReadableCatalog to Calcite schema with given name. + * + * @param parentSchema the parent schema + * @param catalogName name of the catalog + * @param catalog the catalog + */ + public static void registerCatalog( + SchemaPlus parentSchema, + String catalogName, + ReadableCatalog catalog) { + CatalogCalciteSchema newCatalog = new CatalogCalciteSchema(catalogName, catalog); + parentSchema.add(catalogName, newCatalog); + + LOGGER.info("Registered catalog '{}' to Calcite", catalogName); + } + + /** + * A mapping between Flink Catalog's database and Calcite's schema. + * Tables are registered as tables in the schema. + */ + private class DatabaseCalciteSchema implements Schema { + + private final String dbName; + private final ReadableCatalog catalog; + + public DatabaseCalciteSchema(String dbName, ReadableCatalog catalog) { + this.dbName = dbName; + this.catalog = catalog; + } + + @Override + public Table getTable(String tableName) { + LOGGER.info("Getting table '{}' from catalog '{}'", tableName, catalogName); + + ObjectPath tablePath = new ObjectPath(dbName, tableName); + + try { + CatalogBaseTable table = catalog.getTable(tablePath); + + LOGGER.info("Successfully got table '{}' from catalog '{}'", tableName, catalogName); + + // TODO: [FLINK-12257] Convert CatalogBaseTable to org.apache.calcite.schema.Table + // so that planner can use unified catalog APIs + return null; + } catch (TableNotExistException e) { + throw new CatalogException(e); + } + } + + @Override + public Set<String> getTableNames() { + try { + return new HashSet<>(catalog.listTables(dbName)); + } catch (DatabaseNotExistException e) { + throw new CatalogException(e); + } + } + + @Override + public RelProtoDataType getType(String name) { + return new RelProtoDataType() { + @Override + public RelDataType apply(RelDataTypeFactory relDataTypeFactory) { + return relDataTypeFactory.createSqlType(SqlTypeName.valueOf(name)); + } + }; + } + + @Override + public Set<String> getTypeNames() { + return new HashSet<>(); + } + + @Override + public Collection<Function> getFunctions(String s) { + return new HashSet<>(); + } + + @Override + public Set<String> getFunctionNames() { + return new HashSet<>(); + } + + @Override + public Schema getSubSchema(String s) { + throw new UnsupportedOperationException( + "DatabaseCalciteSchema does not support getSubSchema()"); + } + + @Override + public Set<String> getSubSchemaNames() { + throw new UnsupportedOperationException( Review comment: Similar to above, does it make sense to allow trying to get a database out of the table layer? ---------------------------------------------------------------- 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
