Class ThreeNTTConvolutionStrategy

java.lang.Object
org.apfloat.internal.ThreeNTTConvolutionStrategy
All Implemented Interfaces:
ConvolutionStrategy
Direct Known Subclasses:
ParallelThreeNTTConvolutionStrategy

public class ThreeNTTConvolutionStrategy extends Object implements ConvolutionStrategy
Convolution using three Number Theoretic Transforms and the Chinese Remainder Theorem to get the final result.

Multiplication can be done in linear time in the transform domain, where the multiplication is simply an element-by-element multiplication.

All access to this class must be externally synchronized.

Since:
1.7.0
Version:
1.7.0
Author:
Mikko Tommila
  • Field Details

  • Constructor Details

    • ThreeNTTConvolutionStrategy

      public ThreeNTTConvolutionStrategy(int radix, NTTStrategy nttStrategy)
      Creates a new convoluter that uses the specified transform for transforming the data.
      Parameters:
      radix - The radix to be used.
      nttStrategy - The transform to be used.
  • Method Details

    • convolute

      public DataStorage convolute(DataStorage x, DataStorage y, long resultSize) throws ApfloatRuntimeException
      Description copied from interface: ConvolutionStrategy
      Convolutes the two sets of data.
      Specified by:
      convolute in interface ConvolutionStrategy
      Parameters:
      x - First data set.
      y - Second data set.
      resultSize - Number of elements needed in the result data.
      Returns:
      The convolved data.
      Throws:
      ApfloatRuntimeException
    • convoluteOne

      protected DataStorage convoluteOne(DataStorage x, DataStorage y, long length, int modulus, boolean cached) throws ApfloatRuntimeException
      Performs a convolution modulo one modulus, of the specified transform length.
      Parameters:
      x - First data set.
      y - Second data set.
      length - Length of the transformation.
      modulus - Which modulus to use.
      cached - If the result data should be kept cached in memory when possible.
      Returns:
      The result of the convolution for one modulus.
      Throws:
      ApfloatRuntimeException
    • autoConvolute

      protected DataStorage autoConvolute(DataStorage x, long resultSize) throws ApfloatRuntimeException
      Convolutes a data set with itself.
      Parameters:
      x - The data set.
      resultSize - Number of elements needed in the result data.
      Returns:
      The convolved data.
      Throws:
      ApfloatRuntimeException
    • autoConvoluteOne

      protected DataStorage autoConvoluteOne(DataStorage x, long length, int modulus, boolean cached) throws ApfloatRuntimeException
      Performs an autoconvolution modulo one modulus, of the specified transform length.
      Parameters:
      x - The data set.
      length - Length of the transformation.
      modulus - Which modulus to use.
      cached - If the result data should be kept cached in memory when possible.
      Returns:
      The result of the convolution for one modulus.
      Throws:
      ApfloatRuntimeException
    • lock

      protected void lock(long length)
      Lock the execution against a synchronization lock.
      Parameters:
      length - The length of the data being processed for determining the type of lock to use.
    • unlock

      protected void unlock()
      Remove the synchronization lock.
    • createCachedDataStorage

      protected DataStorage createCachedDataStorage(long size) throws ApfloatRuntimeException
      Create a cached (if possible) data storage for the specified number of elements.
      Parameters:
      size - The number of elements.
      Returns:
      The data storage.
      Throws:
      ApfloatRuntimeException
    • createDataStorage

      protected DataStorage createDataStorage(DataStorage dataStorage) throws ApfloatRuntimeException
      Create a cached data storage from the (possibly) cached data storage.
      Parameters:
      dataStorage - The data storage, which may be cached.
      Returns:
      The data storage, which isn't cached.
      Throws:
      ApfloatRuntimeException