Class Hardwood

java.lang.Object

dev.hardwood.Hardwood

All Implemented Interfaces:

AutoCloseable

public class Hardwood
extends Object
implements AutoCloseable

Entry point for reading Parquet files with a shared thread pool.

Use this when reading multiple files to share the executor across readers:

try (Hardwood hardwood = Hardwood.create()) {
    ParquetFileReader file1 = hardwood.open(InputFile.of(path1));
    ParquetFileReader file2 = hardwood.open(InputFile.of(path2));
    // ...
}

For single-file usage, ParquetFileReader.open(InputFile) is simpler.

Method Summary

Modifier and Type	Method	Description
void	close()
static Hardwood	create()	Create a new Hardwood instance with a thread pool sized to available processors.
ParquetFileReader	open(InputFile inputFile)	Open a Parquet file from an InputFile for reading.
MultiFileParquetReader	openAll(List<InputFile> inputFiles)	Open multiple Parquet files for reading with cross-file prefetching.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

create

public static Hardwood create()

Create a new Hardwood instance with a thread pool sized to available processors.

open

public ParquetFileReader open(InputFile inputFile)
                       throws IOException

Open a Parquet file from an InputFile for reading.

The file will be opened and closed automatically; closing the returned reader closes the file.

Throws:

IOException

openAll

public MultiFileParquetReader openAll(List<InputFile> inputFiles)
                               throws IOException

Open multiple Parquet files for reading with cross-file prefetching.

Returns a MultiFileParquetReader that reads the schema from the first file and provides factory methods for row-oriented (MultiFileParquetReader.createRowReader()) or column-oriented (MultiFileParquetReader.createColumnReaders(dev.hardwood.schema.ColumnProjection)) access. The files will be opened automatically as needed.

Parameters:

inputFiles - the input files to read (must not be empty)

Returns:

a MultiFileParquetReader for the given files

Throws:

IOException - if the first file cannot be opened or read

IllegalArgumentException - if the list is empty

close

public void close()

Specified by:

close in interface AutoCloseable