Examples with MetadataReader io.trino.parquet.reader.MetadataReader used on opensource projects

Example 1 with MetadataReader

use of io.trino.parquet.reader.MetadataReader in project trino by trinodb.

the class IcebergPageSourceProvider method createParquetPageSource.

private static ReaderPageSource createParquetPageSource(HdfsEnvironment hdfsEnvironment, ConnectorIdentity identity, Configuration configuration, Path path, long start, long length, long fileSize, List<IcebergColumnHandle> regularColumns, ParquetReaderOptions options, TupleDomain<IcebergColumnHandle> effectivePredicate, FileFormatDataSourceStats fileFormatDataSourceStats, Optional<NameMapping> nameMapping) {
    AggregatedMemoryContext memoryContext = newSimpleAggregatedMemoryContext();
    ParquetDataSource dataSource = null;
    try {
        FileSystem fileSystem = hdfsEnvironment.getFileSystem(identity, path, configuration);
        FSDataInputStream inputStream = hdfsEnvironment.doAs(identity, () -> fileSystem.open(path));
        dataSource = new HdfsParquetDataSource(new ParquetDataSourceId(path.toString()), fileSize, inputStream, fileFormatDataSourceStats, options);
        // extra variable required for lambda below
        ParquetDataSource theDataSource = dataSource;
        ParquetMetadata parquetMetadata = hdfsEnvironment.doAs(identity, () -> MetadataReader.readFooter(theDataSource));
        FileMetaData fileMetaData = parquetMetadata.getFileMetaData();
        MessageType fileSchema = fileMetaData.getSchema();
        if (nameMapping.isPresent() && !ParquetSchemaUtil.hasIds(fileSchema)) {
            // NameMapping conversion is necessary because MetadataReader converts all column names to lowercase and NameMapping is case sensitive
            fileSchema = ParquetSchemaUtil.applyNameMapping(fileSchema, convertToLowercase(nameMapping.get()));
        }
        // Mapping from Iceberg field ID to Parquet fields.
        Map<Integer, org.apache.parquet.schema.Type> parquetIdToField = fileSchema.getFields().stream().filter(field -> field.getId() != null).collect(toImmutableMap(field -> field.getId().intValue(), Function.identity()));
        Optional<ReaderColumns> columnProjections = projectColumns(regularColumns);
        List<IcebergColumnHandle> readColumns = columnProjections.map(readerColumns -> (List<IcebergColumnHandle>) readerColumns.get().stream().map(IcebergColumnHandle.class::cast).collect(toImmutableList())).orElse(regularColumns);
        List<org.apache.parquet.schema.Type> parquetFields = readColumns.stream().map(column -> parquetIdToField.get(column.getId())).collect(toList());
        MessageType requestedSchema = new MessageType(fileSchema.getName(), parquetFields.stream().filter(Objects::nonNull).collect(toImmutableList()));
        Map<List<String>, RichColumnDescriptor> descriptorsByPath = getDescriptors(fileSchema, requestedSchema);
        TupleDomain<ColumnDescriptor> parquetTupleDomain = getParquetTupleDomain(descriptorsByPath, effectivePredicate);
        Predicate parquetPredicate = buildPredicate(requestedSchema, parquetTupleDomain, descriptorsByPath, UTC);
        List<BlockMetaData> blocks = new ArrayList<>();
        for (BlockMetaData block : parquetMetadata.getBlocks()) {
            long firstDataPage = block.getColumns().get(0).getFirstDataPageOffset();
            if (start <= firstDataPage && firstDataPage < start + length && predicateMatches(parquetPredicate, block, dataSource, descriptorsByPath, parquetTupleDomain)) {
                blocks.add(block);
            }
        }
        MessageColumnIO messageColumnIO = getColumnIO(fileSchema, requestedSchema);
        ParquetReader parquetReader = new ParquetReader(Optional.ofNullable(fileMetaData.getCreatedBy()), messageColumnIO, blocks, Optional.empty(), dataSource, UTC, memoryContext, options);
        ImmutableList.Builder<Type> trinoTypes = ImmutableList.builder();
        ImmutableList.Builder<Optional<Field>> internalFields = ImmutableList.builder();
        for (int columnIndex = 0; columnIndex < readColumns.size(); columnIndex++) {
            IcebergColumnHandle column = readColumns.get(columnIndex);
            org.apache.parquet.schema.Type parquetField = parquetFields.get(columnIndex);
            Type trinoType = column.getBaseType();
            trinoTypes.add(trinoType);
            if (parquetField == null) {
                internalFields.add(Optional.empty());
            } else {
                // The top level columns are already mapped by name/id appropriately.
                ColumnIO columnIO = messageColumnIO.getChild(parquetField.getName());
                internalFields.add(IcebergParquetColumnIOConverter.constructField(new FieldContext(trinoType, column.getColumnIdentity()), columnIO));
            }
        }
        return new ReaderPageSource(new ParquetPageSource(parquetReader, trinoTypes.build(), internalFields.build()), columnProjections);
    } catch (IOException | RuntimeException e) {
        try {
            if (dataSource != null) {
                dataSource.close();
            }
        } catch (IOException ignored) {
        }
        if (e instanceof TrinoException) {
            throw (TrinoException) e;
        }
        String message = format("Error opening Iceberg split %s (offset=%s, length=%s): %s", path, start, length, e.getMessage());
        if (e instanceof ParquetCorruptionException) {
            throw new TrinoException(ICEBERG_BAD_DATA, message, e);
        }
        if (e instanceof BlockMissingException) {
            throw new TrinoException(ICEBERG_MISSING_DATA, message, e);
        }
        throw new TrinoException(ICEBERG_CANNOT_OPEN_SPLIT, message, e);
    }
}