vvysotskyi commented on a change in pull request #1430: DRILL-6680: Expose show files command into INFORMATION_SCHEMA URL: https://github.com/apache/drill/pull/1430#discussion_r209544436
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/planner/sql/handlers/ShowFilesHandler.java ########## @@ -0,0 +1,120 @@ +/* + * 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.drill.exec.planner.sql.handlers; + +import org.apache.calcite.schema.SchemaPlus; +import org.apache.calcite.sql.SqlIdentifier; +import org.apache.calcite.sql.SqlLiteral; +import org.apache.calcite.sql.SqlNode; +import org.apache.calcite.sql.SqlNodeList; +import org.apache.calcite.sql.SqlSelect; +import org.apache.calcite.sql.fun.SqlStdOperatorTable; +import org.apache.calcite.sql.parser.SqlParserPos; +import org.apache.calcite.util.Util; +import org.apache.drill.common.exceptions.UserException; +import org.apache.drill.exec.planner.sql.SchemaUtilites; +import org.apache.drill.exec.planner.sql.parser.DrillParserUtil; +import org.apache.drill.exec.planner.sql.parser.SqlShowFiles; +import org.apache.drill.exec.store.AbstractSchema; +import org.apache.drill.exec.store.dfs.WorkspaceSchemaFactory.WorkspaceSchema; +import org.apache.drill.exec.store.ischema.InfoSchemaTableType; +import org.apache.drill.exec.work.foreman.ForemanSetupException; + +import java.util.Arrays; +import java.util.Collections; +import java.util.List; + +import static org.apache.drill.exec.store.ischema.InfoSchemaConstants.FILES_COL_RELATIVE_PATH; +import static org.apache.drill.exec.store.ischema.InfoSchemaConstants.FILES_COL_SCHEMA_NAME; +import static org.apache.drill.exec.store.ischema.InfoSchemaConstants.IS_SCHEMA_NAME; + + +public class ShowFilesHandler extends DefaultSqlHandler { + private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(SetOptionHandler.class); + + public ShowFilesHandler(SqlHandlerConfig config) { + super(config); + } + + /** Rewrite the parse tree as SELECT ... FROM INFORMATION_SCHEMA.FILES ... */ + @Override + public SqlNode rewrite(SqlNode sqlNode) throws ForemanSetupException { + + List<SqlNode> selectList = Collections.singletonList(SqlIdentifier.star(SqlParserPos.ZERO)); + + SqlNode fromClause = new SqlIdentifier( + Arrays.asList(IS_SCHEMA_NAME, InfoSchemaTableType.FILES.name()), null, SqlParserPos.ZERO, null); + + SchemaPlus defaultSchema = config.getConverter().getDefaultSchema(); + SchemaPlus drillSchema = defaultSchema; + + SqlShowFiles showFiles = unwrap(sqlNode, SqlShowFiles.class); + SqlIdentifier from = showFiles.getDb(); + boolean addRelativePathLikeClause = false; + + // Show files can be used without from clause, in which case we display the files in the default schema + if (from != null) { + // We are not sure if the full from clause is just the schema or includes table name, + // first try to see if the full path specified is a schema + drillSchema = SchemaUtilites.findSchema(defaultSchema, from.names); + if (drillSchema == null) { + // Entire from clause is not a schema, try to obtain the schema without the last part of the specified clause. + drillSchema = SchemaUtilites.findSchema(defaultSchema, from.names.subList(0, from.names.size() - 1)); + addRelativePathLikeClause = true; + } + + if (drillSchema == null) { + throw UserException.validationError() + .message("Invalid FROM/IN clause [%s]", from.toString()) + .build(logger); + } + } + + WorkspaceSchema wsSchema; + + try { + AbstractSchema abstractSchema = drillSchema.unwrap(AbstractSchema.class); + if (abstractSchema instanceof WorkspaceSchema) { Review comment: `WorkspaceSchema` uses implementation of `getDefaultSchema()` method from `AbstractSchema` which returns `this` instance. So I think `if` block may be replaced with the statement from `else` branch. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
