Class LongNTTStepStrategy

All Implemented Interfaces:
Parallelizable, NTTStepStrategy
Direct Known Subclasses:
LongAparapiNTTStepStrategy

public class LongNTTStepStrategy extends LongTableFNT implements NTTStepStrategy, Parallelizable
Common methods to calculate Fast Number Theoretic Transforms in parallel using multiple threads.

All access to this class must be externally synchronized.

Since:
1.7.0
Version:
1.9.0
Author:
Mikko Tommila
  • Constructor Details

    • LongNTTStepStrategy

      public LongNTTStepStrategy()
      Default constructor.
  • Method Details

    • multiplyElements

      public void multiplyElements(ArrayAccess arrayAccess, int startRow, int startColumn, int rows, int columns, long length, long totalTransformLength, boolean isInverse, int modulus) throws ApfloatRuntimeException
      Description copied from interface: NTTStepStrategy
      Multiply each matrix element (i, j) by wi * j / totalTransformLength. The matrix size is n1 x n2.
      Specified by:
      multiplyElements in interface NTTStepStrategy
      Parameters:
      arrayAccess - The memory array to multiply.
      startRow - Which row in the whole matrix the starting row in the arrayAccess is.
      startColumn - Which column in the whole matrix the starting column in the arrayAccess is.
      rows - The number of rows in the arrayAccess to multiply.
      columns - The number of columns in the matrix (= n2).
      length - The length of data in the matrix being transformed.
      totalTransformLength - The total transform length, for the scaling factor. Used only for the inverse case.
      isInverse - If the multiplication is done for the inverse transform or not.
      modulus - Index of the modulus.
      Throws:
      ApfloatRuntimeException
    • transformRows

      public void transformRows(ArrayAccess arrayAccess, int length, int count, boolean isInverse, boolean permute, int modulus) throws ApfloatRuntimeException
      Description copied from interface: NTTStepStrategy
      Transform the rows of the data matrix. If only one processor is available, it runs all transforms in the current thread. If more than one processor are available, it dispatches the calculations to multiple threads to parallelize the calculation. The number of processors is determined using ApfloatContext.getNumberOfProcessors().
      Specified by:
      transformRows in interface NTTStepStrategy
      Parameters:
      arrayAccess - The memory array to split to rows and to transform.
      length - Length of one transform (one row).
      count - Number of rows.
      isInverse - true if an inverse transform is performed, false if a forward transform is performed.
      permute - If permutation should be done.
      modulus - Index of the modulus.
      Throws:
      ApfloatRuntimeException
    • getMaxTransformLength

      public long getMaxTransformLength()
      Description copied from interface: NTTStepStrategy
      Get the maximum transform length.
      Specified by:
      getMaxTransformLength in interface NTTStepStrategy
      Returns:
      The maximum transform length.
    • createMultiplyElementsParallelRunnable

      protected ParallelRunnable createMultiplyElementsParallelRunnable(ArrayAccess arrayAccess, int startRow, int startColumn, int rows, int columns, long length, long totalTransformLength, boolean isInverse, int modulus) throws ApfloatRuntimeException
      Create a ParallelRunnable object for multiplying the elements of the matrix.
      Parameters:
      arrayAccess - The memory array to multiply.
      startRow - Which row in the whole matrix the starting row in the arrayAccess is.
      startColumn - Which column in the whole matrix the starting column in the arrayAccess is.
      rows - The number of rows in the arrayAccess to multiply.
      columns - The number of columns in the matrix (= n2).
      length - The length of data in the matrix being transformed.
      totalTransformLength - The total transform length, for the scaling factor. Used only for the inverse case.
      isInverse - If the multiplication is done for the inverse transform or not.
      modulus - Index of the modulus.
      Returns:
      An object suitable for multiplying the elements of the matrix in parallel.
      Throws:
      ApfloatRuntimeException
    • createTransformRowsParallelRunnable

      protected ParallelRunnable createTransformRowsParallelRunnable(ArrayAccess arrayAccess, int length, int count, boolean isInverse, boolean permute, int modulus) throws ApfloatRuntimeException
      Create a ParallelRunnable object for transforming the rows of the matrix.
      Parameters:
      arrayAccess - The memory array to split to rows and to transform.
      length - Length of one transform (one row).
      count - Number of rows.
      isInverse - true if an inverse transform is performed, false if a forward transform is performed.
      permute - If permutation should be done.
      modulus - Index of the modulus.
      Returns:
      An object suitable for transforming the rows of the matrix in parallel.
      Throws:
      ApfloatRuntimeException