uk.ac.starlink.parquet

Class ParquetIO

java.lang.Object

uk.ac.starlink.parquet.ParquetIO

public class ParquetIO
extends Object

Handles all the interactions with the parquet-mr libraries required by the high-level starjava parquet table I/O classes. If the parquet-mr libraries are not present, it may not be possible to instantiate this class.

Since:

9 Apr 2021

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
ParquetIO()

Method Summary

Modifier and Type	Method and Description
ParquetStarTable	readParquet(DataSource datsrc, ParquetTableBuilder builder, ParquetStarTable.Config config, boolean useCache, boolean tryUrl) Reads a parquet table on behalf of a ParquetTableBuilder.
void	writeParquet(StarTable table, ParquetTableWriter writer, OutputStream out) Writes a parqet table to an output stream on behalf of a ParquetTableWriter.
void	writeParquet(StarTable table, ParquetTableWriter writer, String location) Writes a parqet table to a named location on behalf of a ParquetTableWriter.

Methods inherited from class java.lang.Object

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

Constructor Detail

ParquetIO

public ParquetIO()

Method Detail

readParquet

public ParquetStarTable readParquet(DataSource datsrc,
                                    ParquetTableBuilder builder,
                                    ParquetStarTable.Config config,
                                    boolean useCache,
                                    boolean tryUrl)
                             throws IOException

Reads a parquet table on behalf of a ParquetTableBuilder.

Parameters:

datsrc - data source

builder - handler providing configuration

config - table reading configuration

useCache - true for column caching, false for sequential

tryUrl - whether to attempt opening non-file URLs

Returns:

loaded table

Throws:

IOException

writeParquet

public void writeParquet(StarTable table,
                         ParquetTableWriter writer,
                         String location)
                  throws IOException

Writes a parqet table to a named location on behalf of a ParquetTableWriter.

Parameters:

table - table to write

writer - handler providing configuration

location - destination

Throws:

IOException

writeParquet

public void writeParquet(StarTable table,
                         ParquetTableWriter writer,
                         OutputStream out)
                  throws IOException

Writes a parqet table to an output stream on behalf of a ParquetTableWriter.

Parameters:

table - table to write

writer - handler providing configuration

out - destination stream

Throws:

IOException