org.apache.mahout.math.list
Class AbstractList

java.lang.Object
  extended by org.apache.mahout.math.PersistentObject
      extended by org.apache.mahout.math.list.AbstractList
All Implemented Interfaces:
Serializable, Cloneable
Direct Known Subclasses:
AbstractByteList, AbstractCharList, AbstractDoubleList, AbstractFloatList, AbstractIntList, AbstractLongList, AbstractObjectList, AbstractShortList

public abstract class AbstractList
extends PersistentObject

Abstract base class for resizable lists holding objects or primitive data types such as int, float, etc. First see the package summary and javadoc tree view to get the broad picture.

Note that this implementation is not synchronized.

Version:
1.0, 09/24/99
Author:
wolfgang.hoschek@cern.ch
See Also:
ArrayList, Vector, Arrays, Serialized Form

Constructor Summary
AbstractList()
           
 
Method Summary
protected abstract  void beforeInsertDummies(int index, int length)
          Inserts length dummy elements before the specified position into the receiver.
protected static void checkRange(int index, int theSize)
          Checks if the given index is in range.
protected static void checkRangeFromTo(int from, int to, int theSize)
          Checks if the given range is within the contained array's bounds.
 void clear()
          Removes all elements from the receiver.
 boolean isEmpty()
           
 void mergeSort()
          Sorts the receiver into ascending order.
abstract  void mergeSortFromTo(int from, int to)
          Sorts the receiver into ascending order.
 void quickSort()
          Sorts the receiver into ascending order.
abstract  void quickSortFromTo(int from, int to)
          Sorts the specified range of the receiver into ascending order.
 void remove(int index)
          Removes the element at the specified position from the receiver.
abstract  void removeFromTo(int fromIndex, int toIndex)
          Removes from the receiver all elements whose index is between from, inclusive and to, inclusive.
abstract  void reverse()
          Reverses the elements of the receiver.
 void setSize(int newSize)
          Sets the size of the receiver.
abstract  int size()
           
 void sort()
          Sorts the receiver into ascending order.
 void sortFromTo(int from, int to)
          Sorts the specified range of the receiver into ascending order.
 void trimToSize()
          Trims the capacity of the receiver to be the receiver's current size.
 
Methods inherited from class org.apache.mahout.math.PersistentObject
clone
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

AbstractList

public AbstractList()
Method Detail

size

public abstract int size()

isEmpty

public boolean isEmpty()

beforeInsertDummies

protected abstract void beforeInsertDummies(int index,
                                            int length)
Inserts length dummy elements before the specified position into the receiver. Shifts the element currently at that position (if any) and any subsequent elements to the right. This method must set the new size to be size()+length.

Parameters:
index - index before which to insert dummy elements (must be in [0,size])..
length - number of dummy elements to be inserted.
Throws:
IndexOutOfBoundsException - if index < 0 || index > size().

checkRange

protected static void checkRange(int index,
                                 int theSize)
Checks if the given index is in range.


checkRangeFromTo

protected static void checkRangeFromTo(int from,
                                       int to,
                                       int theSize)
Checks if the given range is within the contained array's bounds.

Throws:
IndexOutOfBoundsException - if to!=from-1 || from<0 || from>to || to>=size().

clear

public void clear()
Removes all elements from the receiver. The receiver will be empty after this call returns, but keep its current capacity.


mergeSort

public final void mergeSort()
Sorts the receiver into ascending order. This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.

The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance, and can approach linear performance on nearly sorted lists.

You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set. It is generally better to call sort() or sortFromTo(...) instead, because those methods automatically choose the best sorting algorithm.


mergeSortFromTo

public abstract void mergeSortFromTo(int from,
                                     int to)
Sorts the receiver into ascending order. This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.

The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance, and can approach linear performance on nearly sorted lists.

You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set. It is generally better to call sort() or sortFromTo(...) instead, because those methods automatically choose the best sorting algorithm.

Parameters:
from - the index of the first element (inclusive) to be sorted.
to - the index of the last element (inclusive) to be sorted.
Throws:
IndexOutOfBoundsException - if (from<0 || from>to || to>=size()) && to!=from-1.

quickSort

public final void quickSort()
Sorts the receiver into ascending order. The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.

You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set. It is generally better to call sort() or sortFromTo(...) instead, because those methods automatically choose the best sorting algorithm.


quickSortFromTo

public abstract void quickSortFromTo(int from,
                                     int to)
Sorts the specified range of the receiver into ascending order. The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", Software-Practice and Experience, Vol. 23(11) P. 1249-1265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.

You should never call this method unless you are sure that this particular sorting algorithm is the right one for your data set. It is generally better to call sort() or sortFromTo(...) instead, because those methods automatically choose the best sorting algorithm.

Parameters:
from - the index of the first element (inclusive) to be sorted.
to - the index of the last element (inclusive) to be sorted.
Throws:
IndexOutOfBoundsException - if (from<0 || from>to || to>=size()) && to!=from-1.

remove

public void remove(int index)
Removes the element at the specified position from the receiver. Shifts any subsequent elements to the left.

Parameters:
index - the index of the element to removed.
Throws:
IndexOutOfBoundsException - if index < 0 || index >= size().

removeFromTo

public abstract void removeFromTo(int fromIndex,
                                  int toIndex)
Removes from the receiver all elements whose index is between from, inclusive and to, inclusive. Shifts any succeeding elements to the left (reduces their index). This call shortens the list by (to - from + 1) elements.

Parameters:
fromIndex - index of first element to be removed.
toIndex - index of last element to be removed.
Throws:
IndexOutOfBoundsException - if (from<0 || from>to || to>=size()) && to!=from-1.

reverse

public abstract void reverse()
Reverses the elements of the receiver. Last becomes first, second last becomes second first, and so on.


setSize

public void setSize(int newSize)
Sets the size of the receiver. If the new size is greater than the current size, new null or zero items are added to the end of the receiver. If the new size is less than the current size, all components at index newSize and greater are discarded. This method does not release any superfluos internal memory. Use method trimToSize to release superfluos internal memory.

Parameters:
newSize - the new size of the receiver.
Throws:
IndexOutOfBoundsException - if newSize < 0.

sort

public final void sort()
Sorts the receiver into ascending order. The sorting algorithm is dynamically chosen according to the characteristics of the data set. This implementation simply calls sortFromTo(...). Override sortFromTo(...) if you can determine which sort is most appropriate for the given data set.


sortFromTo

public void sortFromTo(int from,
                       int to)
Sorts the specified range of the receiver into ascending order. The sorting algorithm is dynamically chosen according to the characteristics of the data set. This default implementation simply calls quickSort. Override this method if you can determine which sort is most appropriate for the given data set.

Parameters:
from - the index of the first element (inclusive) to be sorted.
to - the index of the last element (inclusive) to be sorted.
Throws:
IndexOutOfBoundsException - if (from<0 || from>to || to>=size()) && to!=from-1.

trimToSize

public void trimToSize()
Trims the capacity of the receiver to be the receiver's current size. Releases any superfluos internal memory. An application can use this operation to minimize the storage of the receiver.

This default implementation does nothing. Override this method in space efficient implementations.



Copyright © 2008–2014 The Apache Software Foundation. All rights reserved.