Package org.apache.sysds.runtime.compress.cost

Class ACostEstimate

java.lang.Object
org.apache.sysds.runtime.compress.cost.ACostEstimate
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
ComputationCostEstimator, DistinctCostEstimator, HybridCostEstimator, MemoryCostEstimator
public abstract class ACostEstimate extends Object implements Serializable
A cost estimator interface. It is used to estimate the cost at different stages of compression, and used to compare to uncompressed.
See Also:

  • Method Details

    • getCost

      public double getCost(Collection<AColGroup> cgs, int nRows)
      Get the cost of a collection of column groups.
      Parameters:
      cgs - A collection of column groups
      nRows - The number of rows in the column group
      Returns:
      The summed cost of the groups

    • getCost

      public final double getCost(CompressedSizeInfoColGroup g)
      Get cost of a single column group estimate. If the input is null the cost is positive infinity indicating that it is impossible to compress the null case. If the instruction does not care about the inter column group cost, such as in memory cost or in computation cost of right or left matrix multiplication we simply estimate the cost of individual column groups.
      Parameters:
      g - Column group to estimate the cost of
      Returns:
      The Cost of this column group

    • getCost

      public double getCost(CompressedSizeInfo i)
      Get cost of an entire compression plan
      Parameters:
      i - The compression plan to get the cost of
      Returns:
      The cost

    • getCost

      public double getCost(CompressedMatrixBlock cmb)
      Get cost of a compressed matrix block
      Parameters:
      cmb - The compressed matrix block
      Returns:
      The cost

    • getCost

      public abstract double getCost(MatrixBlock mb)
      Get the cost of a matrix block.
      Parameters:
      mb - A MatrixBlock
      Returns:
      The cost subject to the internal cost functions

    • getCost

      public abstract double getCost(AColGroup cg, int nRows)
      Get the cost of a compressed columnGroup.
      Parameters:
      cg - A ColumnGroup
      nRows - The number of rows in the column group
      Returns:
      The cost subject to the internal cost functions

    • shouldSparsify

      public abstract boolean shouldSparsify()
      Ask the cost estimator if it is a good idea to try to sparsify a column group. It is the same as asking if it is a good idea to make FOR on top of the column group.
      Returns:
      true if yes

    • toString

      public String toString()
      Overrides:
      toString in class Object