org.apache.sysds.runtime.compress.bitmap

Class BitmapEncoder

java.lang.Object

org.apache.sysds.runtime.compress.bitmap.BitmapEncoder

public class BitmapEncoder
extends Object

Static functions for encoding bitmaps in various ways.

Constructor Summary

Constructors

Constructor and Description
BitmapEncoder()

Method Summary

Modifier and Type	Method and Description
static ABitmap	extractBitmap(int[] colIndices, MatrixBlock rawBlock, boolean transposed, int estimatedNumberOfUniques) Generate uncompressed bitmaps for a set of columns in an uncompressed matrix block.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitmapEncoder

public BitmapEncoder()

Method Detail

extractBitmap

public static ABitmap extractBitmap(int[] colIndices,
                                    MatrixBlock rawBlock,
                                    boolean transposed,
                                    int estimatedNumberOfUniques)

Generate uncompressed bitmaps for a set of columns in an uncompressed matrix block.

Parameters:

colIndices - Indexes (within the block) of the columns to extract

rawBlock - An uncompressed matrix block; can be dense or sparse

transposed - Boolean specifying if the rawBlock was transposed.

estimatedNumberOfUniques - The number of estimated uniques inside this group. Used to allocated the hashMaps.

Returns:

uncompressed bitmap representation of the columns