diff options
Diffstat (limited to 'contrib/format-ltsv/src/main/java/org/apache/drill/exec/store/ltsv/LTSVRecordReader.java')
-rw-r--r-- | contrib/format-ltsv/src/main/java/org/apache/drill/exec/store/ltsv/LTSVRecordReader.java | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/contrib/format-ltsv/src/main/java/org/apache/drill/exec/store/ltsv/LTSVRecordReader.java b/contrib/format-ltsv/src/main/java/org/apache/drill/exec/store/ltsv/LTSVRecordReader.java new file mode 100644 index 000000000..cb2385013 --- /dev/null +++ b/contrib/format-ltsv/src/main/java/org/apache/drill/exec/store/ltsv/LTSVRecordReader.java @@ -0,0 +1,165 @@ +/* + * 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.ltsv; + +import io.netty.buffer.DrillBuf; +import org.apache.drill.common.AutoCloseables; +import org.apache.drill.common.exceptions.ExecutionSetupException; +import org.apache.drill.common.exceptions.UserException; +import org.apache.drill.common.expression.SchemaPath; +import org.apache.drill.exec.exception.OutOfMemoryException; +import org.apache.drill.exec.ops.FragmentContext; +import org.apache.drill.exec.ops.OperatorContext; +import org.apache.drill.exec.physical.impl.OutputMutator; +import org.apache.drill.exec.store.AbstractRecordReader; +import org.apache.drill.exec.store.dfs.DrillFileSystem; +import org.apache.drill.exec.vector.complex.impl.VectorContainerWriter; +import org.apache.drill.exec.vector.complex.writer.BaseWriter; +import org.apache.hadoop.fs.FSDataInputStream; +import org.apache.hadoop.fs.Path; + +import java.io.BufferedReader; +import java.io.IOException; +import java.io.InputStreamReader; +import java.nio.charset.StandardCharsets; +import java.text.ParseException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.LinkedHashSet; +import java.util.List; +import java.util.Set; + +public class LTSVRecordReader extends AbstractRecordReader { + + private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(LTSVRecordReader.class); + + private static final int MAX_RECORDS_PER_BATCH = 8096; + + private final String inputPath; + + private final FSDataInputStream fsStream; + + private final BufferedReader reader; + + private DrillBuf buffer; + + private VectorContainerWriter writer; + + public LTSVRecordReader(FragmentContext fragmentContext, Path path, DrillFileSystem fileSystem, + List<SchemaPath> columns) throws OutOfMemoryException { + this.inputPath = path.toUri().getPath(); + try { + this.fsStream = fileSystem.open(path); + this.reader = new BufferedReader(new InputStreamReader(fsStream.getWrappedStream(), StandardCharsets.UTF_8)); + this.buffer = fragmentContext.getManagedBuffer(); + setColumns(columns); + + } catch (IOException e) { + String msg = String.format("Failed to open input file: %s", inputPath); + throw UserException.dataReadError(e).message(msg).build(logger); + } + } + + @Override + protected Collection<SchemaPath> transformColumns(Collection<SchemaPath> projected) { + Set<SchemaPath> transformed = new LinkedHashSet<>(); + if (!isStarQuery()) { + for (SchemaPath column : projected) { + transformed.add(column); + } + } else { + transformed.add(SchemaPath.STAR_COLUMN); + } + return transformed; + } + + public void setup(final OperatorContext context, final OutputMutator output) throws ExecutionSetupException { + this.writer = new VectorContainerWriter(output); + } + + public int next() { + this.writer.allocate(); + this.writer.reset(); + + int recordCount = 0; + + try { + BaseWriter.MapWriter map = this.writer.rootAsMap(); + String line = null; + + while (recordCount < MAX_RECORDS_PER_BATCH && (line = this.reader.readLine()) != null) { + // Skip empty lines + if (line.trim().length() == 0) { + continue; + } + + List<String[]> fields = new ArrayList<>(); + for (String field : line.split("\t")) { + int index = field.indexOf(":"); + if (index <= 0) { + throw new ParseException(String.format("Invalid LTSV format: %s\n%d:%s", inputPath, recordCount + 1, line), 0); + } + + String fieldName = field.substring(0, index); + String fieldValue = field.substring(index + 1); + if (selectedColumn(fieldName)) { + fields.add(new String[]{fieldName, fieldValue}); + } + } + + if (fields.size() == 0) { + continue; + } + + this.writer.setPosition(recordCount); + map.start(); + + for (String[] field : fields) { + byte[] bytes = field[1].getBytes(StandardCharsets.UTF_8); + this.buffer = this.buffer.reallocIfNeeded(bytes.length); + this.buffer.setBytes(0, bytes, 0, bytes.length); + map.varChar(field[0]).writeVarChar(0, bytes.length, buffer); + } + + map.end(); + recordCount++; + } + + this.writer.setValueCount(recordCount); + return recordCount; + + } catch (final Exception e) { + String msg = String.format("Failure while reading messages from %s. Record reader was at record: %d", inputPath, recordCount + 1); + throw UserException.dataReadError(e).message(msg).build(logger); + } + } + + private boolean selectedColumn(String fieldName) { + for (SchemaPath col : getColumns()) { + if (col.equals(SchemaPath.STAR_COLUMN) || col.getRootSegment().getPath().equals(fieldName)) { + return true; + } + } + return false; + } + + public void close() throws Exception { + AutoCloseables.close(reader, fsStream); + } + +} |