Package org.apache.sysds.runtime.compress.colgroup

Class ASDC

java.lang.Object
org.apache.sysds.runtime.compress.colgroup.AColGroup
org.apache.sysds.runtime.compress.colgroup.AColGroupCompressed
org.apache.sysds.runtime.compress.colgroup.ADictBasedColGroup
org.apache.sysds.runtime.compress.colgroup.AColGroupValue
org.apache.sysds.runtime.compress.colgroup.AMorphingMMColGroup
org.apache.sysds.runtime.compress.colgroup.ASDC
All Implemented Interfaces:
Serializable, AOffsetsGroup, IContainADictionary, IContainDefaultTuple
Direct Known Subclasses:
ColGroupSDC, ColGroupSDCFOR, ColGroupSDCSingle
public abstract class ASDC extends AMorphingMMColGroup implements AOffsetsGroup, IContainDefaultTuple
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. 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:

  • Method Details

    • getNumRows

      public int getNumRows()

    • getOffsets

      public AOffset getOffsets()
      Specified by:
      getOffsets in interface AOffsetsGroup

    • getNumberOffsets

      public abstract int getNumberOffsets()

    • getCompressionInfo

      public final CompressedSizeInfoColGroup getCompressionInfo(int nRow)
      Description copied from class: AColGroup
      Get the compression info for this column group.
      Specified by:
      getCompressionInfo in class AColGroup
      Parameters:
      nRow - The number of rows in this column group.
      Returns:
      The compression info for this group.

    • getCompressionScheme

      public ICLAScheme getCompressionScheme()
      Description copied from class: AColGroup
      Get the compression scheme for this column group to enable compression of other data.
      Specified by:
      getCompressionScheme in class AColGroup
      Returns:
      The compression scheme of this column group

    • morph

      public AColGroup morph(AColGroup.CompressionType ct, int nRow)
      Description copied from class: AColGroup
      Recompress this column group into a new column group of the given type.
      Overrides:
      morph in class AColGroup
      Parameters:
      ct - The compressionType that the column group should morph into
      nRow - The number of rows in this columngroup.
      Returns:
      A new column group