org.apache.mahout.math.list

Class LongArrayList

java.lang.Object

org.apache.mahout.math.PersistentObject

org.apache.mahout.math.list.AbstractList

org.apache.mahout.math.list.AbstractLongList

org.apache.mahout.math.list.LongArrayList

All Implemented Interfaces:

Serializable, Cloneable, LongBufferConsumer

public class LongArrayList
extends AbstractLongList
implements Cloneable

Resizable list holding long elements; implemented with arrays.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.mahout.math.list.AbstractLongList

size

Constructor Summary

Constructors

Constructor and Description
LongArrayList() Constructs an empty list.
LongArrayList(int initialCapacity) Constructs an empty list with the specified initial capacity.
LongArrayList(long[] elements) Constructs a list containing the specified elements.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(long element) Appends the specified element to the end of this list.
void	beforeInsert(int index, long element) Inserts the specified element before the specified position into the receiver.
int	binarySearchFromTo(long key, int from, int to) Searches the receiver for the specified value using the binary search algorithm.
Object	clone() Returns a deep copy of the receiver.
LongArrayList	copy() Returns a deep copy of the receiver; uses clone() and casts the result.
long[]	elements() Returns the elements currently stored, including invalid elements between size and capacity, if any.
AbstractLongList	elements(long[] elements) Sets the receiver's elements to be the specified array (not a copy of it).
void	ensureCapacity(int minCapacity) Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory.
boolean	equals(Object otherObj) Compares the specified Object with the receiver.
boolean	forEach(LongProcedure procedure) Applies a procedure to each element of the receiver, if any.
long	get(int index) Returns the element at the specified position in the receiver.
long	getQuick(int index) Returns the element at the specified position in the receiver; WARNING: Does not check preconditions.
int	indexOfFromTo(long element, int from, int to) Returns the index of the first occurrence of the specified element.
int	lastIndexOfFromTo(long element, int from, int to) Returns the index of the last occurrence of the specified element.
AbstractLongList	partFromTo(int from, int to) Returns a new list of the part of the receiver between from, inclusive, and to, inclusive.
boolean	removeAll(AbstractLongList other) Removes from the receiver all elements that are contained in the specified list.
void	replaceFromToWithFrom(int from, int to, AbstractLongList other, int otherFrom) Replaces a number of elements in the receiver with the same number of elements of another list.
boolean	retainAll(AbstractLongList other) Retains (keeps) only the elements in the receiver that are contained in the specified other list.
void	reverse() Reverses the elements of the receiver.
void	set(int index, long element) Replaces the element at the specified position in the receiver with the specified element.
void	setQuick(int index, long element) Replaces the element at the specified position in the receiver with the specified element; WARNING: Does not check preconditions.
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.list.AbstractLongList

addAllOf, addAllOf, addAllOfFromTo, beforeInsertAllOfFromTo, beforeInsertDummies, binarySearch, contains, delete, fillFromToWith, indexOf, lastIndexOf, mergeSortFromTo, mergeSortFromTo, quickSortFromTo, quickSortFromTo, removeFromTo, replaceFromToWithFromTo, setSizeRaw, size, times, toArray, toList, toString

Methods inherited from class org.apache.mahout.math.list.AbstractList

checkRange, checkRangeFromTo, clear, isEmpty, mergeSort, quickSort, remove, setSize, sort

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LongArrayList

public LongArrayList()

Constructs an empty list.

LongArrayList

public LongArrayList(long[] elements)

Constructs a list containing the specified elements. The initial size and capacity of the list is the length of the array. WARNING: For efficiency reasons and to keep memory usage low, the array is not copied. So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.

Parameters:

elements - the array to be backed by the the constructed list

LongArrayList

public LongArrayList(int initialCapacity)

Constructs an empty list with the specified initial capacity.

Parameters:

initialCapacity - the number of elements the receiver can hold without auto-expanding itself by allocating new internal memory.

Method Detail

add

public void add(long element)

Appends the specified element to the end of this list.

Overrides:

add in class AbstractLongList

Parameters:

element - element to be appended to this list.

beforeInsert

public void beforeInsert(int index,
                long element)

Inserts the specified element before the specified position into the receiver. Shifts the element currently at that position (if any) and any subsequent elements to the right.

Overrides:

beforeInsert in class AbstractLongList

Parameters:

index - index before which the specified element is to be inserted (must be in [0,size]).

element - element to be inserted.

Throws:

IndexOutOfBoundsException - index is out of range (index < 0 || index > size()).

binarySearchFromTo

public int binarySearchFromTo(long key,
                     int from,
                     int to)

Searches the receiver for the specified value using the binary search algorithm. The receiver must must be sorted (as by the sort method) prior to making this call. If it is not sorted, the results are undefined: in particular, the call may enter an infinite loop. If the receiver contains multiple elements equal to the specified object, there is no guarantee which instance will be found.

Overrides:

binarySearchFromTo in class AbstractLongList

Parameters:

key - the value to be searched for.

from - the leftmost search position, inclusive.

to - the rightmost search position, inclusive.

Returns:

index of the search key, if it is contained in the receiver; otherwise, (-(insertion point) - 1). The insertion point is defined as the the point at which the value would be inserted into the receiver: the index of the first element greater than the key, or receiver.size(), if all elements in the receiver are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

See Also:

BinarySearch, Arrays

clone

public Object clone()

Returns a deep copy of the receiver.

Overrides:

clone in class AbstractLongList

Returns:

a deep copy of the receiver.

copy

public LongArrayList copy()

Returns a deep copy of the receiver; uses clone() and casts the result.

Returns:

a deep copy of the receiver.

elements

public long[] elements()

Returns the elements currently stored, including invalid elements between size and capacity, if any. WARNING: For efficiency reasons and to keep memory usage low, the array is not copied. So if subsequently you modify the returned array directly via the [] operator, be sure you know what you're doing.

Overrides:

elements in class AbstractLongList

Returns:

the elements currently stored.

elements

public final AbstractLongList elements(long[] elements)

Sets the receiver's elements to be the specified array (not a copy of it). The size and capacity of the list is the length of the array. WARNING: For efficiency reasons and to keep memory usage low, the array is not copied. So if subsequently you modify the specified array directly via the [] operator, be sure you know what you're doing.

Overrides:

elements in class AbstractLongList

Parameters:

elements - the new elements to be stored.

Returns:

the receiver itself.

ensureCapacity

public void ensureCapacity(int minCapacity)

Ensures that the receiver can hold at least the specified number of elements without needing to allocate new internal memory. If necessary, allocates new internal memory and increases the capacity of the receiver.

Specified by:

ensureCapacity in class AbstractLongList

Parameters:

minCapacity - the desired minimum capacity.

equals

public boolean equals(Object otherObj)

Compares the specified Object with the receiver. Returns true if and only if the specified Object is also an ArrayList of the same type, both Lists have the same size, and all corresponding pairs of elements in the two Lists are identical. In other words, two Lists are defined to be equal if they contain the same elements in the same order.

Overrides:

equals in class AbstractLongList

Parameters:

otherObj - the Object to be compared for equality with the receiver.

Returns:

true if the specified Object is equal to the receiver.

forEach

public boolean forEach(LongProcedure procedure)

Applies a procedure to each element of the receiver, if any. Starts at index 0, moving rightwards.

Overrides:

forEach in class AbstractLongList

Parameters:

procedure - the procedure to be applied. Stops iteration if the procedure returns false, otherwise continues.

Returns:

false if the procedure stopped before all elements where iterated over, true otherwise.

get

public long get(int index)

Returns the element at the specified position in the receiver.

Overrides:

get in class AbstractLongList

Parameters:

index - index of element to return.

Throws:

IndexOutOfBoundsException - index is out of range (index < 0 || index >= size()).

getQuick

public long getQuick(int index)

Returns the element at the specified position in the receiver; WARNING: Does not check preconditions. Provided with invalid parameters this method may return invalid elements without throwing any exception! You should only use this method when you are absolutely sure that the index is within bounds. Precondition (unchecked): index >= 0 && index < size().

Specified by:

getQuick in class AbstractLongList

Parameters:

index - index of element to return.

indexOfFromTo

public int indexOfFromTo(long element,
                int from,
                int to)

Returns the index of the first occurrence of the specified element. Returns -1 if the receiver does not contain this element. Searches between from, inclusive and to, inclusive. Tests for identity.

Overrides:

indexOfFromTo in class AbstractLongList

Parameters:

element - element to search for.

from - the leftmost search position, inclusive.

to - the rightmost search position, inclusive.

Returns:

the index of the first occurrence of the element in the receiver; returns -1 if the element is not found.

Throws:

IndexOutOfBoundsException - index is out of range (size()>0 && (from<0 || from>to || to>=size())).

lastIndexOfFromTo

public int lastIndexOfFromTo(long element,
                    int from,
                    int to)

Returns the index of the last occurrence of the specified element. Returns -1 if the receiver does not contain this element. Searches beginning at to, inclusive until from, inclusive. Tests for identity.

Overrides:

lastIndexOfFromTo in class AbstractLongList

Parameters:

element - element to search for.

from - the leftmost search position, inclusive.

to - the rightmost search position, inclusive.

Returns:

the index of the last occurrence of the element in the receiver; returns -1 if the element is not found.

Throws:

IndexOutOfBoundsException - index is out of range (size()>0 && (from<0 || from>to || to>=size())).

partFromTo

public AbstractLongList partFromTo(int from,
                          int to)

Returns a new list of the part of the receiver between from, inclusive, and to, inclusive.

Overrides:

partFromTo in class AbstractLongList

Parameters:

from - the index of the first element (inclusive).

to - the index of the last element (inclusive).

Returns:

a new list

Throws:

IndexOutOfBoundsException - index is out of range (size()>0 && (from<0 || from>to || to>=size())).

removeAll

public boolean removeAll(AbstractLongList other)

Removes from the receiver all elements that are contained in the specified list. Tests for identity.

Overrides:

removeAll in class AbstractLongList

Parameters:

other - the other list.

Returns:

true if the receiver changed as a result of the call.

replaceFromToWithFrom

public void replaceFromToWithFrom(int from,
                         int to,
                         AbstractLongList other,
                         int otherFrom)

Replaces a number of elements in the receiver with the same number of elements of another list. Replaces elements in the receiver, between from (inclusive) and to (inclusive), with elements of other, starting from otherFrom (inclusive).

Overrides:

replaceFromToWithFrom in class AbstractLongList

Parameters:

from - the position of the first element to be replaced in the receiver

to - the position of the last element to be replaced in the receiver

other - list holding elements to be copied into the receiver.

otherFrom - position of first element within other list to be copied.

retainAll

public boolean retainAll(AbstractLongList other)

Retains (keeps) only the elements in the receiver that are contained in the specified other list. In other words, removes from the receiver all of its elements that are not contained in the specified other list.

Overrides:

retainAll in class AbstractLongList

Parameters:

other - the other list to test against.

Returns:

true if the receiver changed as a result of the call.

reverse

public void reverse()

Reverses the elements of the receiver. Last becomes first, second last becomes second first, and so on.

Overrides:

reverse in class AbstractLongList

set

public void set(int index,
       long element)

Replaces the element at the specified position in the receiver with the specified element.

Overrides:

set in class AbstractLongList

Parameters:

index - index of element to replace.

element - element to be stored at the specified position.

Throws:

IndexOutOfBoundsException - index is out of range (index < 0 || index >= size()).

setQuick

public void setQuick(int index,
            long element)

Replaces the element at the specified position in the receiver with the specified element; WARNING: Does not check preconditions. Provided with invalid parameters this method may access invalid indexes without throwing any exception! You should only use this method when you are absolutely sure that the index is within bounds. Precondition (unchecked): index >= 0 && index < size().

Specified by:

setQuick in class AbstractLongList

Parameters:

index - index of element to replace.

element - element to be stored at the specified position.

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. Currently quicksort and countsort are considered. Countsort is not always applicable, but if applicable, it usually outperforms quicksort by a factor of 3-4.

Best case performance: O(N).

Worst case performance: O(N^2) (a degenerated quicksort).

Best case space requirements: 0 KB.

Worst case space requirements: 40 KB.

Overrides:

sortFromTo in class AbstractList

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 - index is out of range (size()>0 && (from<0 || from>to || to>=size())).

trimToSize

public void trimToSize()

Trims the capacity of the receiver to be the receiver's current size. Releases any superfluous internal memory. An application can use this operation to minimize the storage of the receiver.

Overrides:

trimToSize in class AbstractList