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/**
* 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.parquet.hadoop;
import static org.apache.parquet.hadoop.ParquetInputFormat.SPLIT_FILES;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapreduce.InputSplit;
import org.apache.hadoop.mapreduce.RecordReader;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
import org.apache.parquet.CorruptDeltaByteArrays;
import org.apache.parquet.ParquetReadOptions;
import org.apache.parquet.column.Encoding;
import org.apache.parquet.filter.UnboundRecordFilter;
import org.apache.parquet.filter2.compat.FilterCompat;
import org.apache.parquet.filter2.compat.FilterCompat.Filter;
import org.apache.parquet.hadoop.api.ReadSupport;
import org.apache.parquet.hadoop.metadata.BlockMetaData;
import org.apache.parquet.hadoop.metadata.ColumnChunkMetaData;
import org.apache.parquet.hadoop.metadata.FileMetaData;
import org.apache.parquet.hadoop.util.ContextUtil;
import org.apache.parquet.hadoop.util.HadoopInputFile;
import org.apache.parquet.HadoopReadOptions;
import org.apache.parquet.hadoop.util.counters.BenchmarkCounter;
import org.apache.parquet.io.ParquetDecodingException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Reads the records from a block of a Parquet file
*
* @see ParquetInputFormat
*
* @param type of the materialized records
*/
public class ParquetRecordReader extends RecordReader {
private static final Logger LOG = LoggerFactory.getLogger(ParquetRecordReader.class);
private final InternalParquetRecordReader internalReader;
/**
* @param readSupport Object which helps reads files of the given type, e.g. Thrift, Avro.
*/
public ParquetRecordReader(ReadSupport readSupport) {
this(readSupport, FilterCompat.NOOP);
}
/**
* @param readSupport Object which helps reads files of the given type, e.g. Thrift, Avro.
* @param filter for filtering individual records
*/
public ParquetRecordReader(ReadSupport readSupport, Filter filter) {
internalReader = new InternalParquetRecordReader(readSupport, filter);
}
/**
* @param readSupport Object which helps reads files of the given type, e.g. Thrift, Avro.
* @param filter for filtering individual records
* @deprecated will be removed in 2.0.0.
*/
@Deprecated
public ParquetRecordReader(ReadSupport readSupport, UnboundRecordFilter filter) {
this(readSupport, FilterCompat.get(filter));
}
/**
* {@inheritDoc}
*/
@Override
public void close() throws IOException {
internalReader.close();
}
/**
* always returns null
*/
@Override
public Void getCurrentKey() throws IOException, InterruptedException {
return null;
}
/**
* {@inheritDoc}
*/
@Override
public T getCurrentValue() throws IOException,
InterruptedException {
return internalReader.getCurrentValue();
}
/**
* {@inheritDoc}
*/
@Override
public float getProgress() throws IOException, InterruptedException {
return internalReader.getProgress();
}
/**
* {@inheritDoc}
*/
@Override
public void initialize(InputSplit inputSplit, TaskAttemptContext context)
throws IOException, InterruptedException {
if (ContextUtil.hasCounterMethod(context)) {
BenchmarkCounter.initCounterFromContext(context);
} else {
LOG.error(
String.format("Can not initialize counter because the class '%s' does not have a '.getCounterMethod'",
context.getClass().getCanonicalName()));
}
initializeInternalReader(toParquetSplit(inputSplit), ContextUtil.getConfiguration(context));
}
public void initialize(InputSplit inputSplit, Configuration configuration, Reporter reporter)
throws IOException, InterruptedException {
BenchmarkCounter.initCounterFromReporter(reporter,configuration);
initializeInternalReader(toParquetSplit(inputSplit), configuration);
}
private void initializeInternalReader(ParquetInputSplit split, Configuration configuration) throws IOException {
Path path = split.getPath();
long[] rowGroupOffsets = split.getRowGroupOffsets();
// if task.side.metadata is set, rowGroupOffsets is null
ParquetReadOptions.Builder optionsBuilder = HadoopReadOptions.builder(configuration, path);
if (rowGroupOffsets != null) {
optionsBuilder.withOffsets(rowGroupOffsets);
} else {
optionsBuilder.withRange(split.getStart(), split.getEnd());
}
// open a reader with the metadata filter
ParquetFileReader reader = ParquetFileReader.open(
HadoopInputFile.fromPath(path, configuration), optionsBuilder.build());
if (rowGroupOffsets != null) {
// verify a row group was found for each offset
List blocks = reader.getFooter().getBlocks();
if (blocks.size() != rowGroupOffsets.length) {
throw new IllegalStateException(
"All of the offsets in the split should be found in the file."
+ " expected: " + Arrays.toString(rowGroupOffsets)
+ " found: " + blocks);
}
}
if (!reader.getRowGroups().isEmpty()) {
checkDeltaByteArrayProblem(
reader.getFooter().getFileMetaData(), configuration,
reader.getRowGroups().get(0));
}
internalReader.initialize(reader, configuration);
}
private void checkDeltaByteArrayProblem(FileMetaData meta, Configuration conf, BlockMetaData block) {
// splitting files?
if (conf.getBoolean(ParquetInputFormat.SPLIT_FILES, true)) {
// this is okay if not using DELTA_BYTE_ARRAY with the bug
Set encodings = new HashSet();
for (ColumnChunkMetaData column : block.getColumns()) {
encodings.addAll(column.getEncodings());
}
for (Encoding encoding : encodings) {
if (CorruptDeltaByteArrays.requiresSequentialReads(meta.getCreatedBy(), encoding)) {
throw new ParquetDecodingException("Cannot read data due to " +
"PARQUET-246: to read safely, set " + SPLIT_FILES + " to false");
}
}
}
}
/**
* {@inheritDoc}
*/
@Override
public boolean nextKeyValue() throws IOException, InterruptedException {
return internalReader.nextKeyValue();
}
private ParquetInputSplit toParquetSplit(InputSplit split) throws IOException {
if (split instanceof ParquetInputSplit) {
return (ParquetInputSplit) split;
} else if (split instanceof FileSplit) {
return ParquetInputSplit.from((FileSplit) split);
} else if (split instanceof org.apache.hadoop.mapred.FileSplit) {
return ParquetInputSplit.from(
(org.apache.hadoop.mapred.FileSplit) split);
} else {
throw new IllegalArgumentException(
"Invalid split (not a FileSplit or ParquetInputSplit): " + split);
}
}
}
