| /* |
| * 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.http; |
| |
| import com.univocity.parsers.csv.CsvParser; |
| import com.univocity.parsers.csv.CsvParserSettings; |
| import okhttp3.HttpUrl; |
| import org.apache.drill.common.AutoCloseables; |
| import org.apache.drill.common.exceptions.ChildErrorContext; |
| import org.apache.drill.common.exceptions.CustomErrorContext; |
| import org.apache.drill.common.exceptions.UserException; |
| import org.apache.drill.common.types.TypeProtos; |
| import org.apache.drill.exec.ExecConstants; |
| import org.apache.drill.exec.physical.impl.scan.framework.SchemaNegotiator; |
| import org.apache.drill.exec.physical.resultSet.ResultSetLoader; |
| import org.apache.drill.exec.physical.resultSet.RowSetLoader; |
| import org.apache.drill.exec.record.metadata.SchemaBuilder; |
| import org.apache.drill.exec.record.metadata.TupleMetadata; |
| import org.apache.drill.exec.store.ImplicitColumnUtils.ImplicitColumns; |
| import org.apache.drill.exec.store.http.paginator.Paginator; |
| import org.apache.drill.exec.store.http.util.SimpleHttp; |
| import org.apache.drill.exec.vector.accessor.ScalarWriter; |
| import org.apache.drill.shaded.guava.com.google.common.base.Strings; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import java.io.File; |
| import java.io.InputStream; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| public class HttpCSVBatchReader extends HttpBatchReader { |
| private final HttpSubScan subScan; |
| private final CsvParserSettings csvSettings; |
| private final int maxRecords; |
| private CsvParser csvReader; |
| private List<StringColumnWriter> columnWriters; |
| private String[] firstRow; |
| private SchemaBuilder builder; |
| private RowSetLoader rowWriter; |
| private InputStream inStream; |
| private ResultSetLoader resultLoader; |
| |
| private static final Logger logger = LoggerFactory.getLogger(HttpCSVBatchReader.class); |
| |
| public HttpCSVBatchReader(HttpSubScan subScan) { |
| super(subScan); |
| this.subScan = subScan; |
| this.maxRecords = subScan.maxRecords(); |
| |
| this.csvSettings = new CsvParserSettings(); |
| csvSettings.setLineSeparatorDetectionEnabled(true); |
| } |
| |
| public HttpCSVBatchReader(HttpSubScan subScan, Paginator paginator) { |
| super(subScan, paginator); |
| this.subScan = subScan; |
| this.maxRecords = subScan.maxRecords(); |
| |
| this.csvSettings = new CsvParserSettings(); |
| csvSettings.setLineSeparatorDetectionEnabled(true); |
| } |
| |
| @Override |
| public boolean open(SchemaNegotiator negotiator) { |
| |
| // Result set loader setup |
| String tempDirPath = negotiator.drillConfig().getString(ExecConstants.DRILL_TMP_DIR); |
| |
| HttpUrl url = buildUrl(); |
| |
| CustomErrorContext errorContext = new ChildErrorContext(negotiator.parentErrorContext()) { |
| @Override |
| public void addContext(UserException.Builder builder) { |
| super.addContext(builder); |
| builder.addContext("URL", url.toString()); |
| } |
| }; |
| negotiator.setErrorContext(errorContext); |
| |
| // Http client setup |
| SimpleHttp http = SimpleHttp.builder() |
| .scanDefn(subScan) |
| .url(url) |
| .tempDir(new File(tempDirPath)) |
| .proxyConfig(proxySettings(negotiator.drillConfig(), url)) |
| .errorContext(errorContext) |
| .build(); |
| |
| // CSV loader setup |
| inStream = http.getInputStream(); |
| |
| this.csvReader = new CsvParser(csvSettings); |
| csvReader.beginParsing(inStream); |
| |
| // Build the Schema |
| builder = new SchemaBuilder(); |
| TupleMetadata drillSchema = buildSchema(); |
| negotiator.tableSchema(drillSchema, true); |
| resultLoader = negotiator.build(); |
| |
| // Add implicit columns |
| if (implicitColumnsAreProjected()) { |
| implicitColumns = new ImplicitColumns(resultLoader.writer()); |
| buildImplicitColumns(); |
| populateImplicitFieldMap(http); |
| } |
| |
| // Create ScalarWriters |
| rowWriter = resultLoader.writer(); |
| populateWriterArray(); |
| |
| // Close cache resources |
| http.close(); |
| return true; |
| } |
| |
| @Override |
| public boolean next() { |
| while (!rowWriter.isFull()) { |
| if (rowWriter.limitReached(maxRecords)) { |
| return false; |
| } |
| if (!processRow()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public void close() { |
| logger.debug("Closing URL: {}", baseUrl); |
| AutoCloseables.closeSilently(inStream); |
| } |
| |
| private TupleMetadata buildSchema() { |
| firstRow = csvReader.parseNext(); |
| if (firstRow != null) { |
| for (String value : firstRow) { |
| builder.addNullable(value, TypeProtos.MinorType.VARCHAR); |
| } |
| } |
| return builder.buildSchema(); |
| } |
| |
| private void populateWriterArray() { |
| // Case for empty result set |
| if (firstRow == null || firstRow.length == 0) { |
| return; |
| } |
| |
| columnWriters = new ArrayList<>(); |
| |
| int colPosition = 0; |
| for (String value : firstRow) { |
| columnWriters.add(new StringColumnWriter(value, rowWriter, colPosition)); |
| colPosition++; |
| } |
| } |
| |
| private boolean processRow() { |
| String[] nextRow = csvReader.parseNext(); |
| if (nextRow == null) { |
| |
| if (paginator != null && |
| maxRecords < 0 && (resultLoader.totalRowCount()) < paginator.getPageSize()) { |
| paginator.notifyPartialPage(); |
| } |
| return false; |
| } |
| rowWriter.start(); |
| for (StringColumnWriter columnWriter : columnWriters) { |
| columnWriter.load(nextRow); |
| } |
| |
| if (implicitColumnsAreProjected()) { |
| implicitColumns.writeImplicitColumns(); |
| } |
| |
| rowWriter.save(); |
| return true; |
| } |
| |
| public abstract static class ColumnWriter { |
| |
| final String colName; |
| ScalarWriter columnWriter; |
| int columnIndex; |
| |
| public ColumnWriter(String colName, ScalarWriter writer, int columnIndex) { |
| this.colName = colName; |
| this.columnWriter = writer; |
| this.columnIndex = columnIndex; |
| } |
| |
| public void load(String[] record) {} |
| } |
| |
| public static class StringColumnWriter extends ColumnWriter { |
| |
| StringColumnWriter(String colName, RowSetLoader rowWriter, int columnIndex) { |
| super(colName, rowWriter.scalar(colName), columnIndex); |
| } |
| |
| @Override |
| public void load(String[] record) { |
| String value = record[columnIndex]; |
| if (Strings.isNullOrEmpty(value)) { |
| columnWriter.setNull(); |
| } else { |
| columnWriter.setString(value); |
| } |
| } |
| } |
| } |