it.unimi.dsi.fastutil.objects
Class ReferenceArrayList

java.lang.Object
  extended byit.unimi.dsi.fastutil.objects.AbstractReferenceCollection
      extended byit.unimi.dsi.fastutil.objects.AbstractReferenceList
          extended byit.unimi.dsi.fastutil.objects.ReferenceArrayList
All Implemented Interfaces:
Cloneable, Collection, List, RandomAccess, ReferenceCollection, ReferenceList, Serializable, Stack

public class ReferenceArrayList
extends AbstractReferenceList
implements RandomAccess, Cloneable, Serializable

A type-specific array-based list; provides some additional methods that use polymorphism to reduce type juggling.

This class implements a lightweight, fast, open, optimized, reuse-oriented version of array-based lists. Instances of this class represent a list with an array that is enlarged as needed when new entries are created (by dividing the current length by the golden ratio), but is never made smaller (even on a clear()). A family of trimming methods lets you control the size of the backing array; this is particularly useful if you reuse instances of this class. Range checks are equivalent to those of java.util's classes, but they are delayed as much as possible. The backing array is exposed by the elements() method.

This class implements the bulk methods removeElements(), addElements() and getElements() using high-performance system calls (e.g., System.arraycopy() instead of expensive loops.

See Also:
ArrayList, Serialized Form

Field Summary
static int DEFAULT_INITIAL_CAPACITY
          The initial default capacity of an array list.
static long serialVersionUID
           
 
Constructor Summary
ReferenceArrayList()
          Creates a new array list with DEFAULT_INITIAL_CAPACITY capacity.
ReferenceArrayList(Collection c)
          Creates a new array list and fills it with a given collection.
ReferenceArrayList(int capacity)
          Creates a new array list with given capacity.
ReferenceArrayList(Iterator i)
          Creates a new array list and fills it with the elements returned by an iterator..
ReferenceArrayList(Object[] a)
          Creates a new array list and fills it with the elements of a given array.
ReferenceArrayList(Object[] a, int offset, int length)
          Creates a new array list and fills it with the elements of a given array.
ReferenceArrayList(ObjectIterator i)
          Creates a new array list and fills it with the elements returned by a type-specific iterator..
ReferenceArrayList(ReferenceCollection c)
          Creates a new array list and fills it with a given type-specific collection.
ReferenceArrayList(ReferenceList l)
          Creates a new array list and fills it with a given type-specific list.
 
Method Summary
 void add(int index, Object k)
           
 boolean add(Object k)
           
 boolean addAll(int index, ReferenceCollection c)
          Delegates to a more generic method.
 boolean addAll(int index, ReferenceList l)
          Delegates to a more generic method.
 boolean addAll(ReferenceList l)
          Delegates to a more generic method.
 void addElements(int index, Object[] a, int offset, int length)
          Adds elements to this type-specific list using optimized system calls.
 void clear()
           
 Object clone()
           
 Object[] elements()
          Returns the backing array of this list.
 void ensureCapacity(int capacity)
          Ensures that this array list can contain the given number of entries without resizing.
 boolean equals(ReferenceArrayList l)
          Compares this type-specific array list to another one.
 Object get(int index)
           
 void getElements(int from, Object[] a, int offset, int length)
          Copies element of this type-specific list into the given array using optimized system calls.
 int indexOf(Object k)
           
 boolean isEmpty()
          Checks whether the stack is empty.
 int lastIndexOf(Object k)
           
 ObjectListIterator objectListIterator(int index)
          Returns a type-specific list iterator on the list starting at a given index.
 boolean rem(Object k)
           
 Object remove(int index)
           
 void removeElements(int from, int to)
          Removes elements of this type-specific list using optimized system calls.
 Object set(int index, Object k)
           
 int size()
           
 void size(int size)
          Sets the size of this list.
 void trim()
          Trims this array list so that the capacity is equal to the size.
 void trim(int n)
          Trims the backing array if it is too large.
static ReferenceArrayList wrap(Object[] a)
          Wraps a given array into an array list.
static ReferenceArrayList wrap(Object[] a, int length)
          Wraps a given array into an array list of given size.
 
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReferenceList
addAll, addAll, addAll, addElements, contains, equals, hashCode, listIterator, listIterator, objectIterator, objectListIterator, peek, pop, push, referenceSubList, subList, top, toString
 
Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractReferenceCollection
containsAll, iterator, remove, removeAll, retainAll, toArray, toArray
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.List
containsAll, iterator, remove, removeAll, retainAll, toArray, toArray
 

Field Detail

DEFAULT_INITIAL_CAPACITY

public static final int DEFAULT_INITIAL_CAPACITY
The initial default capacity of an array list.

See Also:
Constant Field Values

serialVersionUID

public static final long serialVersionUID
See Also:
Constant Field Values
Constructor Detail

ReferenceArrayList

public ReferenceArrayList(int capacity)
Creates a new array list with given capacity.

Parameters:
capacity - the initial capacity of the array list (may be 0).

ReferenceArrayList

public ReferenceArrayList()
Creates a new array list with DEFAULT_INITIAL_CAPACITY capacity.


ReferenceArrayList

public ReferenceArrayList(Collection c)
Creates a new array list and fills it with a given collection.

Parameters:
c - a collection that will be used to fill the array list.

ReferenceArrayList

public ReferenceArrayList(ReferenceCollection c)
Creates a new array list and fills it with a given type-specific collection.

Parameters:
c - a type-specific collection that will be used to fill the array list.

ReferenceArrayList

public ReferenceArrayList(ReferenceList l)
Creates a new array list and fills it with a given type-specific list.

Parameters:
l - a type-specific list that will be used to fill the array list.

ReferenceArrayList

public ReferenceArrayList(Object[] a)
Creates a new array list and fills it with the elements of a given array.

Parameters:
a - an array whose elements will be used to fill the array list.

ReferenceArrayList

public ReferenceArrayList(Object[] a,
                          int offset,
                          int length)
Creates a new array list and fills it with the elements of a given array.

Parameters:
a - an array whose elements will be used to fill the array list.
offset - the first element to use.
length - the number of elements to use.

ReferenceArrayList

public ReferenceArrayList(Iterator i)
Creates a new array list and fills it with the elements returned by an iterator..

Parameters:
i - an iterator whose returned elements will fill the array list.

ReferenceArrayList

public ReferenceArrayList(ObjectIterator i)
Creates a new array list and fills it with the elements returned by a type-specific iterator..

Parameters:
i - a type-specific iterator whose returned elements will fill the array list.
Method Detail

elements

public Object[] elements()
Returns the backing array of this list.

Returns:
the backing array.

wrap

public static ReferenceArrayList wrap(Object[] a,
                                      int length)
Wraps a given array into an array list of given size.

Parameters:
a - an array to wrap.
length - the length of the resulting array list.
Returns:
a new array list of the given size, wrapping the given array.

wrap

public static ReferenceArrayList wrap(Object[] a)
Wraps a given array into an array list.

Parameters:
a - an array to wrap.
Returns:
a new array list wrapping the given array.

ensureCapacity

public void ensureCapacity(int capacity)
Ensures that this array list can contain the given number of entries without resizing.

Parameters:
capacity - the new minimum capacity for this array list.

add

public void add(int index,
                Object k)
Specified by:
add in interface List
Overrides:
add in class AbstractReferenceList

add

public boolean add(Object k)
Specified by:
add in interface List
Overrides:
add in class AbstractReferenceCollection

addAll

public boolean addAll(int index,
                      ReferenceCollection c)
Description copied from class: AbstractReferenceList
Delegates to a more generic method.

Overrides:
addAll in class AbstractReferenceList

addAll

public boolean addAll(int index,
                      ReferenceList l)
Description copied from class: AbstractReferenceList
Delegates to a more generic method.

Overrides:
addAll in class AbstractReferenceList

addAll

public boolean addAll(ReferenceList l)
Description copied from class: AbstractReferenceList
Delegates to a more generic method.

Overrides:
addAll in class AbstractReferenceList

get

public Object get(int index)
Specified by:
get in interface List

indexOf

public int indexOf(Object k)
Specified by:
indexOf in interface List
Overrides:
indexOf in class AbstractReferenceList

lastIndexOf

public int lastIndexOf(Object k)
Specified by:
lastIndexOf in interface List
Overrides:
lastIndexOf in class AbstractReferenceList

remove

public Object remove(int index)
Specified by:
remove in interface List
Overrides:
remove in class AbstractReferenceList

rem

public boolean rem(Object k)
Overrides:
rem in class AbstractReferenceList

set

public Object set(int index,
                  Object k)
Specified by:
set in interface List
Overrides:
set in class AbstractReferenceList

clear

public void clear()
Specified by:
clear in interface List
Overrides:
clear in class AbstractReferenceCollection

size

public int size()
Specified by:
size in interface List

size

public void size(int size)
Description copied from interface: ReferenceList
Sets the size of this list.

If the specified size is smaller than the current size, the last elements are discarded. Otherwise, they are filled with 0/null/false.

Specified by:
size in interface ReferenceList
Overrides:
size in class AbstractReferenceList

isEmpty

public boolean isEmpty()
Description copied from interface: Stack
Checks whether the stack is empty.

Specified by:
isEmpty in interface List
Overrides:
isEmpty in class AbstractReferenceCollection

trim

public void trim()
Trims this array list so that the capacity is equal to the size.

See Also:
ArrayList.trimToSize()

trim

public void trim(int n)
Trims the backing array if it is too large. If the current array length is smaller than or equal to n, this method does nothing. Otherwise, it trims the array length to the maximum between n and size().

This method is useful when reusing lists. Clearing a list leaves the array length untouched. If you are reusing a list many times, you can call this method with a typical size to avoid keeping around a very large array just because of a few large transient lists.

Parameters:
n - the threshold for the trimming.

getElements

public void getElements(int from,
                        Object[] a,
                        int offset,
                        int length)
Copies element of this type-specific list into the given array using optimized system calls.

Specified by:
getElements in interface ReferenceList
Overrides:
getElements in class AbstractReferenceList
Parameters:
from - the start index (inclusive).
a - the destination array.
offset - the offset into the destination array where to store the first element copied.
length - the number of elements to be copied.

removeElements

public void removeElements(int from,
                           int to)
Removes elements of this type-specific list using optimized system calls.

Specified by:
removeElements in interface ReferenceList
Overrides:
removeElements in class AbstractReferenceList
Parameters:
from - the start index (inclusive).
to - the end index (exclusive).

addElements

public void addElements(int index,
                        Object[] a,
                        int offset,
                        int length)
Adds elements to this type-specific list using optimized system calls.

Specified by:
addElements in interface ReferenceList
Overrides:
addElements in class AbstractReferenceList
Parameters:
index - the index at which to add elements.
a - the array containing the elements.
offset - the offset of the first element to add.
length - the number of elements to add.

objectListIterator

public ObjectListIterator objectListIterator(int index)
Description copied from interface: ReferenceList
Returns a type-specific list iterator on the list starting at a given index.

The iterator returned by the List.listIterator() method and by this method are identical; however, using this method you can save a type casting.

Specified by:
objectListIterator in interface ReferenceList
See Also:
List.listIterator(int)

clone

public Object clone()

equals

public boolean equals(ReferenceArrayList l)
Compares this type-specific array list to another one.

This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.

Parameters:
l - a type-specific array list.
Returns:
true if the argument contains the same elements of this type-specific array list.