cgivre commented on code in PR #2836: URL: https://github.com/apache/drill/pull/2836#discussion_r1451758017
########## contrib/format-daffodil/src/main/java/org/apache/drill/exec/store/daffodil/DaffodilBatchReader.java: ########## @@ -0,0 +1,181 @@ +/* + * 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.store.daffodil; + +import org.apache.daffodil.japi.DataProcessor; +import org.apache.drill.common.AutoCloseables; +import org.apache.drill.common.exceptions.CustomErrorContext; +import org.apache.drill.common.exceptions.UserException; +import org.apache.drill.exec.physical.impl.scan.v3.ManagedReader; +import org.apache.drill.exec.physical.impl.scan.v3.file.FileDescrip; +import org.apache.drill.exec.physical.impl.scan.v3.file.FileSchemaNegotiator; +import org.apache.drill.exec.physical.resultSet.RowSetLoader; +import org.apache.drill.exec.record.metadata.TupleMetadata; +import org.apache.drill.exec.store.daffodil.schema.DaffodilDataProcessorFactory; +import org.apache.drill.exec.store.dfs.DrillFileSystem; +import org.apache.drill.exec.store.dfs.easy.EasySubScan; +import org.apache.hadoop.fs.Path; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.io.InputStream; +import java.net.URI; +import java.net.URISyntaxException; +import java.util.Objects; + +import static org.apache.drill.exec.store.daffodil.schema.DaffodilDataProcessorFactory.*; +import static org.apache.drill.exec.store.daffodil.schema.DrillDaffodilSchemaUtils.daffodilDataProcessorToDrillSchema; + +public class DaffodilBatchReader implements ManagedReader { + + private static final Logger logger = LoggerFactory.getLogger(DaffodilBatchReader.class); + private final RowSetLoader rowSetLoader; + private final CustomErrorContext errorContext; + private final DaffodilMessageParser dafParser; + private final InputStream dataInputStream; + + public DaffodilBatchReader(DaffodilReaderConfig readerConfig, EasySubScan scan, + FileSchemaNegotiator negotiator) { + + errorContext = negotiator.parentErrorContext(); + DaffodilFormatConfig dafConfig = readerConfig.plugin.getConfig(); + + String schemaURIString = dafConfig.getSchemaURI(); // "schema/complexArray1.dfdl.xsd"; + String rootName = dafConfig.getRootName(); + String rootNamespace = dafConfig.getRootNamespace(); + boolean validationMode = dafConfig.getValidationMode(); + + URI dfdlSchemaURI; + try { + dfdlSchemaURI = new URI(schemaURIString); + } catch (URISyntaxException e) { + throw UserException.validationError(e).build(logger); + } + + FileDescrip file = negotiator.file(); + DrillFileSystem fs = file.fileSystem(); + URI fsSchemaURI = fs.getUri().resolve(dfdlSchemaURI); + + DaffodilDataProcessorFactory dpf = new DaffodilDataProcessorFactory(); + DataProcessor dp; + try { + dp = dpf.getDataProcessor(fsSchemaURI, validationMode, rootName, rootNamespace); + } catch (CompileFailure e) { + throw UserException.dataReadError(e) + .message(String.format("Failed to get Daffodil DFDL processor for: %s", fsSchemaURI)) + .addContext(errorContext).addContext(e.getMessage()).build(logger); + } + // Create the corresponding Drill schema. + // Note: this could be a very large schema. Think of a large complex RDBMS schema, + // all of it, hundreds of tables, but all part of the same metadata tree. + TupleMetadata drillSchema = daffodilDataProcessorToDrillSchema(dp); + // Inform Drill about the schema + negotiator.tableSchema(drillSchema, true); + + // + // DATA TIME: Next we construct the runtime objects, and open files. + // + // We get the DaffodilMessageParser, which is a stateful driver for daffodil that + // actually does the parsing. + rowSetLoader = negotiator.build().writer(); + + // We construct the Daffodil InfosetOutputter which the daffodil parser uses to + // convert infoset event calls to fill in a Drill row via a rowSetLoader. + DaffodilDrillInfosetOutputter outputter = new DaffodilDrillInfosetOutputter(rowSetLoader); + + // Now we can set up the dafParser with the outputter it will drive with + // the parser-produced infoset. + dafParser = new DaffodilMessageParser(dp); // needs further initialization after this. + dafParser.setInfosetOutputter(outputter); + + Path dataPath = file.split().getPath(); + // Lastly, we open the data stream + try { + dataInputStream = fs.openPossiblyCompressedStream(dataPath); + } catch (IOException e) { + throw UserException.dataReadError(e) + .message(String.format("Failed to open input file: %s", dataPath.toString())) + .addContext(errorContext).addContext(e.getMessage()).build(logger); + } + // And lastly,... tell daffodil the input data stream. + dafParser.setInputStream(dataInputStream); + } + + /** + * This is the core of actual processing - data movement from Daffodil to Drill. + * <p> + * If there is space in the batch, and there is data available to parse then this calls the + * daffodil parser, which parses data, delivering it to the rowWriter by way of the infoset + * outputter. + * <p> + * Repeats until the rowWriter is full (a batch is full), or there is no more data, or a parse + * error ends execution with a throw. + * <p> + * Validation errors and other warnings are not errors and are logged but do not cause parsing to + * fail/throw. + * + * @return true if there are rows retrieved, false if no rows were retrieved, which means no more + * will ever be retrieved (end of data). + * @throws RuntimeException + * on parse errors. + */ + @Override + public boolean next() { + // Check assumed invariants + // We don't know if there is data or not. This could be called on an empty data file. + // We DO know that this won't be called if there is no space in the batch for even 1 + // row. + if (dafParser.isEOF()) { + return false; // return without even checking for more rows or trying to parse. + } + while (rowSetLoader.start() && !dafParser.isEOF()) { // we never zero-trip this loop. + // the predicate is always true once. + dafParser.parse(); + if (dafParser.isProcessingError()) { + assert (Objects.nonNull(dafParser.getDiagnostics())); + throw UserException.dataReadError().message(dafParser.getDiagnosticsAsString()) + .addContext(errorContext).build(logger); + } + if (dafParser.isValidationError()) { + logger.warn(dafParser.getDiagnosticsAsString()); Review Comment: @mbeckerle The question I'd have is whether the query can proceed if validation fails. (I don't know the answer) If the answer is no, then we need to halt execution ASAP and throw an exception. If the answer is it can proceed, but the data might be less than ideal, maybe we add a configuration option which will allow the user to decide the behavior on a validation failure. I could imagine situations where you have Drill unable to read a huge file because someone fat fingered a quotation mark somewhere or something like that. In a situation like that, sometimes you might just want to say I'll accept a row or two of bad data just so I can read the whole file. -- 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. To unsubscribe, e-mail: dev-unsubscr...@drill.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
