| /* |
| * 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.calcite.jdbc; |
| |
| import org.apache.calcite.DataContext; |
| |
| import org.apache.calcite.linq4j.tree.Expression; |
| import org.apache.calcite.linq4j.tree.Expressions; |
| import org.apache.calcite.schema.SchemaPlus; |
| import org.apache.calcite.util.BuiltInMethod; |
| import org.apache.drill.common.exceptions.UserException; |
| import org.apache.drill.common.exceptions.UserExceptionUtils; |
| import org.apache.drill.exec.planner.sql.SchemaUtilites; |
| import org.apache.drill.exec.store.AbstractSchema; |
| import org.apache.drill.exec.store.SchemaConfig; |
| import org.apache.drill.exec.store.StoragePlugin; |
| import org.apache.drill.exec.store.StoragePluginRegistry; |
| import org.apache.drill.exec.store.StoragePluginRegistry.PluginException; |
| import org.apache.drill.exec.store.SubSchemaWrapper; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| * Loads schemas from storage plugins later when {@link #getSubSchema(String, boolean)} |
| * is called. |
| */ |
| public class DynamicRootSchema extends DynamicSchema { |
| private static final Logger logger = LoggerFactory.getLogger(DynamicRootSchema.class); |
| |
| private static final String ROOT_SCHEMA_NAME = ""; |
| |
| private final SchemaConfig schemaConfig; |
| private final StoragePluginRegistry storages; |
| |
| /** Creates a root schema. */ |
| DynamicRootSchema(StoragePluginRegistry storages, SchemaConfig schemaConfig) { |
| super(null, new RootSchema(), ROOT_SCHEMA_NAME); |
| this.schemaConfig = schemaConfig; |
| this.storages = storages; |
| } |
| |
| @Override |
| protected CalciteSchema getImplicitSubSchema(String schemaName, |
| boolean caseSensitive) { |
| // Drill registers schemas in lower case, see AbstractSchema constructor |
| schemaName = schemaName == null ? null : schemaName.toLowerCase(); |
| CalciteSchema retSchema = getSubSchemaMap().get(schemaName); |
| if (retSchema != null) { |
| return retSchema; |
| } |
| |
| loadSchemaFactory(schemaName, caseSensitive); |
| retSchema = getSubSchemaMap().get(schemaName); |
| return retSchema; |
| } |
| |
| /** |
| * Loads schema factory(storage plugin) for specified {@code schemaName} |
| * @param schemaName the name of the schema |
| * @param caseSensitive whether matching for the schema name is case sensitive |
| */ |
| private void loadSchemaFactory(String schemaName, boolean caseSensitive) { |
| try { |
| SchemaPlus schemaPlus = this.plus(); |
| StoragePlugin plugin = storages.getPlugin(schemaName); |
| if (plugin != null) { |
| plugin.registerSchemas(schemaConfig, schemaPlus); |
| return; |
| } |
| |
| // Could not find the plugin of schemaName. The schemaName could be `dfs.tmp`, a 2nd level schema under 'dfs' |
| List<String> paths = SchemaUtilites.getSchemaPathAsList(schemaName); |
| if (paths.size() == 2) { |
| plugin = storages.getPlugin(paths.get(0)); |
| if (plugin == null) { |
| return; |
| } |
| |
| // Looking for the SchemaPlus for the top level (e.g. 'dfs') of schemaName (e.g. 'dfs.tmp') |
| SchemaPlus firstLevelSchema = schemaPlus.getSubSchema(paths.get(0)); |
| if (firstLevelSchema == null) { |
| // register schema for this storage plugin to 'this'. |
| plugin.registerSchemas(schemaConfig, schemaPlus); |
| firstLevelSchema = schemaPlus.getSubSchema(paths.get(0)); |
| } |
| // Load second level schemas for this storage plugin |
| List<SchemaPlus> secondLevelSchemas = new ArrayList<>(); |
| for (String secondLevelSchemaName : firstLevelSchema.getSubSchemaNames()) { |
| secondLevelSchemas.add(firstLevelSchema.getSubSchema(secondLevelSchemaName)); |
| } |
| |
| for (SchemaPlus schema : secondLevelSchemas) { |
| org.apache.drill.exec.store.AbstractSchema drillSchema; |
| try { |
| drillSchema = schema.unwrap(org.apache.drill.exec.store.AbstractSchema.class); |
| } catch (ClassCastException e) { |
| throw new RuntimeException(String.format("Schema '%s' is not expected under root schema", schema.getName())); |
| } |
| SubSchemaWrapper wrapper = new SubSchemaWrapper(drillSchema); |
| schemaPlus.add(wrapper.getName(), wrapper); |
| } |
| } |
| } catch(PluginException | IOException ex) { |
| logger.warn("Failed to load schema for \"" + schemaName + "\"!", ex); |
| // We can't proceed further without a schema, throw a runtime exception. |
| UserException.Builder exceptBuilder = |
| UserException |
| .resourceError(ex) |
| .message("Failed to load schema for \"" + schemaName + "\"!") |
| .addContext(ex.getClass().getName() + ": " + ex.getMessage()) |
| .addContext(UserExceptionUtils.getUserHint(ex)); //Provide hint if it exists |
| throw exceptBuilder.build(logger); |
| } |
| } |
| |
| static class RootSchema extends AbstractSchema { |
| |
| public RootSchema() { |
| super(Collections.emptyList(), ROOT_SCHEMA_NAME); |
| } |
| |
| @Override |
| public String getTypeName() { |
| return ROOT_SCHEMA_NAME; |
| } |
| |
| @Override public Expression getExpression(SchemaPlus parentSchema, |
| String name) { |
| return Expressions.call( |
| DataContext.ROOT, |
| BuiltInMethod.DATA_CONTEXT_GET_ROOT_SCHEMA.method); |
| } |
| } |
| } |
| |