Package net.algart.arrays

Class IntJArrayHolder

java.lang.Object
net.algart.arrays.IntJArrayHolder
public final class IntJArrayHolder extends Object
A simple class allowing to reuse Java int[] array many times. It can be useful, when the algorithm usually allocates int[] array with the same size many times (changing the size is a rare event). In this case, you can replace "new" operator (that spends time for zero-initialing new array) with quickNew(int) method, that probably will work very quickly. The previously allocated array is stored inside the object in a SoftReference.

This class is thread-safe: you may use the same instance of this class in several threads.

Author:
Daniel Alievsky

  • Constructor Details

    • IntJArrayHolder

      public IntJArrayHolder()

  • Method Details

    • quickNew

      public int[] quickNew(Matrix<?> matrix)
      Equivalent to quickNew(matrix.size()).
      Parameters:
      matrix - some AlgART matrix.
      Returns:
      newly created "new int[newArrayLength]" or previously allocated array, if it exists and has identical length.
      Throws:
      NullPointerException - if the argument is null.
      TooLargeArrayException - if matrix.size() > Integer.MAX_VALUE.

    • quickNew

      public int[] quickNew(long newArrayLength)
      Equivalent of quickNew(int) method, but in addition it checks that newArrayLength is actually 32-bit value (newArrayLength==(int)newArrayLength) and, if not, throws TooLargeArrayException.
      Parameters:
      newArrayLength - required array length.
      Returns:
      newly created "new int[newArrayLength]" or previously allocated array, if it exists and has identical length.
      Throws:
      IllegalArgumentException - if newArrayLength < 0.
      TooLargeArrayException - if newArrayLength > Integer.MAX_VALUE.

    • quickNew

      public int[] quickNew(int newArrayLength)
      Quick analog of new int[newArrayLength]}. If this method is called several times for allocating data with the same size, this method returns previously allocated array. (Previous array is stored in SoftReference and, if there is not enough memory, can be utilized by garbage collector; in this case, this method will just use "new" operator.)

      Please remember: unlike standard new operator, the returned array is usually not filled by zeros.

      Parameters:
      newArrayLength - required array length.
      Returns:
      newly created "new int[newArrayLength]" or previously allocated array, if it exists and has identical length.
      Throws:
      IllegalArgumentException - if newArrayLength < 0

    • quickClone

      public int[] quickClone(int[] array)
      Quick analog of array.clone(). Equivalent to the following operators: 
           int[] result = quickNew(int) quickNew}(array.length);
     System.arraycopy(array, 0, result, 0, array.length);
     (return result)
      Parameters:
      array - some array to clone.
      Returns:
      exact copy of the source array.
      Throws:
      NullPointerException - if the passed array is null.