use of parquet.hadoop.ParquetRecordReader in project presto by prestodb.
the class ParquetHiveRecordCursor method createParquetRecordReader.
private ParquetRecordReader<FakeParquetRecord> createParquetRecordReader(HdfsEnvironment hdfsEnvironment, String sessionUser, Configuration configuration, Path path, long start, long length, List<HiveColumnHandle> columns, boolean useParquetColumnNames, TypeManager typeManager, boolean predicatePushdownEnabled, TupleDomain<HiveColumnHandle> effectivePredicate) {
ParquetDataSource dataSource = null;
try {
FileSystem fileSystem = hdfsEnvironment.getFileSystem(sessionUser, path, configuration);
dataSource = buildHdfsParquetDataSource(fileSystem, path, start, length);
ParquetMetadata parquetMetadata = hdfsEnvironment.doAs(sessionUser, () -> ParquetFileReader.readFooter(configuration, path, NO_FILTER));
List<BlockMetaData> blocks = parquetMetadata.getBlocks();
FileMetaData fileMetaData = parquetMetadata.getFileMetaData();
MessageType fileSchema = fileMetaData.getSchema();
PrestoReadSupport readSupport = new PrestoReadSupport(useParquetColumnNames, columns, fileSchema);
List<parquet.schema.Type> fields = columns.stream().filter(column -> column.getColumnType() == REGULAR).map(column -> getParquetType(column, fileSchema, useParquetColumnNames)).filter(Objects::nonNull).collect(toList());
MessageType requestedSchema = new MessageType(fileSchema.getName(), fields);
LongArrayList offsets = new LongArrayList(blocks.size());
for (BlockMetaData block : blocks) {
long firstDataPage = block.getColumns().get(0).getFirstDataPageOffset();
if (firstDataPage >= start && firstDataPage < start + length) {
if (predicatePushdownEnabled) {
ParquetPredicate parquetPredicate = buildParquetPredicate(columns, effectivePredicate, fileMetaData.getSchema(), typeManager);
if (predicateMatches(parquetPredicate, block, dataSource, requestedSchema, effectivePredicate)) {
offsets.add(block.getStartingPos());
}
} else {
offsets.add(block.getStartingPos());
}
}
}
ParquetInputSplit split = new ParquetInputSplit(path, start, start + length, length, null, offsets.toLongArray());
TaskAttemptContext taskContext = ContextUtil.newTaskAttemptContext(configuration, new TaskAttemptID());
return hdfsEnvironment.doAs(sessionUser, () -> {
ParquetRecordReader<FakeParquetRecord> realReader = new PrestoParquetRecordReader(readSupport);
realReader.initialize(split, taskContext);
return realReader;
});
} catch (Exception e) {
Throwables.propagateIfInstanceOf(e, PrestoException.class);
if (e instanceof InterruptedException) {
Thread.currentThread().interrupt();
throw Throwables.propagate(e);
}
String message = format("Error opening Hive split %s (offset=%s, length=%s): %s", path, start, length, e.getMessage());
if (e.getClass().getSimpleName().equals("BlockMissingException")) {
throw new PrestoException(HIVE_MISSING_DATA, message, e);
}
throw new PrestoException(HIVE_CANNOT_OPEN_SPLIT, message, e);
} finally {
if (dataSource != null) {
try {
dataSource.close();
} catch (IOException ignored) {
}
}
}
}
Aggregations