org.apache.sysds.runtime.compress.colgroup

Class ColGroupSDC

java.lang.Object

org.apache.sysds.runtime.compress.colgroup.AColGroup

org.apache.sysds.runtime.compress.colgroup.ColGroupCompressed

org.apache.sysds.runtime.compress.colgroup.ColGroupValue

org.apache.sysds.runtime.compress.colgroup.ColGroupSDC

All Implemented Interfaces:

Serializable, Cloneable

public class ColGroupSDC
extends ColGroupValue

Column group that sparsely encodes the dictionary values. The idea is that all values is encoded with indexes except the most common one. the most common one can be inferred by not being included in the indexes. If the values are very sparse then the most common one is zero. This column group is handy in cases where sparse unsafe operations is executed on very sparse columns. Then the zeros would be materialized in the group without any overhead.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.sysds.runtime.compress.colgroup.AColGroup

AColGroup.CompressionType

Method Summary

Modifier and Type	Method and Description
AColGroup	binaryRowOp(BinaryOperator op, double[] v, boolean sparseSafe, boolean left) Perform a binary row operation.
void	countNonZerosPerRow(int[] rnnz, int rl, int ru) Count the number of non-zeros per row
long	estimateInMemorySize() Get the upper bound estimate of in memory allocation for the column group.
double	get(int r, int c) Get the value at a global row/column position.
org.apache.sysds.runtime.compress.colgroup.AColGroup.ColGroupType	getColGroupType() Internally get the specific type of ColGroup, this could be extracted from the object but that does not allow for nice switches in the code.
AColGroup.CompressionType	getCompType() Obtain the compression type.
int[]	getCounts(int[] counts)
int[]	getCounts(int rl, int ru, int[] counts)
long	getExactSizeOnDisk() Returns the exact serialized size of column group.
int	getIndex(int r)
int	getIndexStructureHash()
void	preAggregate(MatrixBlock m, MatrixBlock preAgg, int rl, int ru) Pre aggregate for left Multiplication.
Dictionary	preAggregateThatDDCStructure(ColGroupDDC that, Dictionary ret)
Dictionary	preAggregateThatSDCSingleStructure(ColGroupSDCSingle that, Dictionary ret, boolean preModified)
Dictionary	preAggregateThatSDCSingleZerosStructure(ColGroupSDCSingleZeros that, Dictionary ret)
Dictionary	preAggregateThatSDCStructure(ColGroupSDC that, Dictionary ret, boolean preModified)
Dictionary	preAggregateThatSDCZerosStructure(ColGroupSDCZeros that, Dictionary ret)
void	readFields(DataInput in) Deserialize column group from data input.
boolean	sameIndexStructure(ColGroupCompressed that)
AColGroup	scalarOperation(ScalarOperator op) Perform the specified scalar operation directly on the compressed column group, without decompressing individual cells if possible.
String	toString()
void	write(DataOutput out) Serializes column group to data output.

Methods inherited from class org.apache.sysds.runtime.compress.colgroup.ColGroupValue

addMinMax, cleanupThreadLocalMemory, containsValue, copy, copyAndSet, copyAndSet, copyAndSet, copyAndSet, decompressToBlockSafe, decompressToBlockUnSafe, getCachedCounts, getCounts, getCounts, getDictionary, getIfCountsType, getNumberNonZeros, getNumValues, getValues, getValuesAsBlock, isDense, isLossy, leftMultByAColGroup, leftMultByMatrix, preAggregateThatIndexStructure, replace, rightMultByMatrix, setupThreadLocalMemory, tsmm, tsmm

Methods inherited from class org.apache.sysds.runtime.compress.colgroup.ColGroupCompressed

getMax, getMin, getNumRows, unaryAggregateOperations, unaryAggregateOperations

Methods inherited from class org.apache.sysds.runtime.compress.colgroup.AColGroup

decompressColumnToBlockUnSafe, decompressToBlockUnSafe, getColIndices, getNumCols, leftMultByMatrix, shiftColIndices, sliceColumn, sliceColumns

Methods inherited from class java.lang.Object

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

Method Detail

getCompType

public AColGroup.CompressionType getCompType()

Description copied from class: AColGroup

Obtain the compression type.

Specified by:

getCompType in class AColGroup

Returns:

How the elements of the column group are compressed.

getColGroupType

public org.apache.sysds.runtime.compress.colgroup.AColGroup.ColGroupType getColGroupType()

Description copied from class: AColGroup

Internally get the specific type of ColGroup, this could be extracted from the object but that does not allow for nice switches in the code.

Returns:

ColGroupType of the object.

get

public double get(int r,
                  int c)

Description copied from class: AColGroup

Get the value at a global row/column position.

Specified by:

get in class AColGroup

Parameters:

r - row

c - column

Returns:

value at the row/column position

countNonZerosPerRow

public void countNonZerosPerRow(int[] rnnz,
                                int rl,
                                int ru)

Description copied from class: AColGroup

Count the number of non-zeros per row

Specified by:

countNonZerosPerRow in class AColGroup

Parameters:

rnnz - non-zeros per row

rl - row lower bound, inclusive

ru - row upper bound, exclusive

getCounts

public int[] getCounts(int[] counts)

Specified by:

getCounts in class ColGroupValue

getCounts

public int[] getCounts(int rl,
                       int ru,
                       int[] counts)

Specified by:

getCounts in class ColGroupValue

getIndex

public int getIndex(int r)

preAggregate

public void preAggregate(MatrixBlock m,
                         MatrixBlock preAgg,
                         int rl,
                         int ru)

Description copied from class: ColGroupValue

Pre aggregate for left Multiplication.

Parameters:

m - Matrix to preAggregate

preAgg - Matrix to preAggregate into

rl - Start row

ru - End row

estimateInMemorySize

public long estimateInMemorySize()

Description copied from class: AColGroup

Get the upper bound estimate of in memory allocation for the column group.

Overrides:

estimateInMemorySize in class ColGroupValue

Returns:

an upper bound on the number of bytes used to store this ColGroup in memory.

scalarOperation

public AColGroup scalarOperation(ScalarOperator op)

Description copied from class: AColGroup

Perform the specified scalar operation directly on the compressed column group, without decompressing individual cells if possible.

Specified by:

scalarOperation in class AColGroup

Parameters:

op - operation to perform

Returns:

version of this column group with the operation applied

binaryRowOp

public AColGroup binaryRowOp(BinaryOperator op,
                             double[] v,
                             boolean sparseSafe,
                             boolean left)

Description copied from class: AColGroup

Perform a binary row operation.

Specified by:

binaryRowOp in class AColGroup

Parameters:

op - The operation to execute

v - The vector of values to apply, should be same length as dictionary length.

sparseSafe - True if the operation return 0 on all instances of values in v -- op(v[?], 0)

left - Specifies if the operation is executed on the left or right side of the values contained.

Returns:

A updated column group with the new values.

write

public void write(DataOutput out)
           throws IOException

Description copied from class: AColGroup

Serializes column group to data output.

Overrides:

write in class ColGroupValue

Parameters:

out - data output

Throws:

IOException - if IOException occurs

readFields

public void readFields(DataInput in)
                throws IOException

Description copied from class: AColGroup

Deserialize column group from data input.

Overrides:

readFields in class ColGroupValue

Parameters:

in - data input

Throws:

IOException - if IOException occurs

getExactSizeOnDisk

public long getExactSizeOnDisk()

Description copied from class: AColGroup

Returns the exact serialized size of column group. This can be used for example for buffer preallocation.

Overrides:

getExactSizeOnDisk in class ColGroupValue

Returns:

exact serialized size for column group

sameIndexStructure

public boolean sameIndexStructure(ColGroupCompressed that)

getIndexStructureHash

public int getIndexStructureHash()

toString

public String toString()

Overrides:

toString in class ColGroupValue

preAggregateThatDDCStructure

public Dictionary preAggregateThatDDCStructure(ColGroupDDC that,
                                               Dictionary ret)

preAggregateThatSDCStructure

public Dictionary preAggregateThatSDCStructure(ColGroupSDC that,
                                               Dictionary ret,
                                               boolean preModified)

preAggregateThatSDCZerosStructure

public Dictionary preAggregateThatSDCZerosStructure(ColGroupSDCZeros that,
                                                    Dictionary ret)

preAggregateThatSDCSingleZerosStructure

public Dictionary preAggregateThatSDCSingleZerosStructure(ColGroupSDCSingleZeros that,
                                                          Dictionary ret)

preAggregateThatSDCSingleStructure

public Dictionary preAggregateThatSDCSingleStructure(ColGroupSDCSingle that,
                                                     Dictionary ret,
                                                     boolean preModified)