org.apache.sysds.runtime.compress.colgroup

Class ColGroupIO

java.lang.Object

org.apache.sysds.runtime.compress.colgroup.ColGroupIO

public class ColGroupIO
extends Object

This has the IO responsibility of ColGroups, such that it enables to read and write ColGroups to and from a DataInput and DataOutput

Constructor Summary

Constructors

Constructor and Description
ColGroupIO()

Method Summary

Modifier and Type	Method and Description
static long	getExactSizeOnDisk(List<AColGroup> colGroups) Get the size on disk for the given list of column groups
static List<AColGroup>	readGroups(DataInput in, int nRows) Read groups from a file.
static void	writeGroups(DataOutput out, List<AColGroup> colGroups) Writes the ColGroups out to the DataOutput.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColGroupIO

public ColGroupIO()

Method Detail

readGroups

public static List<AColGroup> readGroups(DataInput in,
                                         int nRows)
                                  throws IOException

Read groups from a file. Note that the information about how many should be in the file already.

Parameters:

in - The Data input object to read from.

nRows - The number of rows in the read groups.

Returns:

Return a List containing the ColGroups from the DataInput.

Throws:

IOException - Throws IO Exception if the in refuses to read data.

writeGroups

public static void writeGroups(DataOutput out,
                               List<AColGroup> colGroups)
                        throws IOException

Writes the ColGroups out to the DataOutput.

Parameters:

out - The DataOutput the ColGroups are written to

colGroups - List of the ColGroups to write to file.

Throws:

IOException - Throws IO Exception if the out refuses to write.

getExactSizeOnDisk

public static long getExactSizeOnDisk(List<AColGroup> colGroups)

Get the size on disk for the given list of column groups

Parameters:

colGroups - A List of column groups to see the disk space required for.

Returns:

The exact disk size required for writing the compressed matrix.