public class ReferenceArrayList<K> extends AbstractReferenceList<K> implements java.util.RandomAccess, java.lang.Cloneable, java.io.Serializable
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 doubling the current length), 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. If an instance
of this class was created by wrapping,
backing-array reallocations will be performed using reflection, so that
elements()
can return an array of the same type of the original array: the comments
about efficiency made in ObjectArrays
apply here.
Moreover, you must take into consideration that assignment to an array
not of type Object[]
is slower due to type checking.
This class implements the bulk methods removeElements()
,
addElements()
and getElements()
using
high-performance system calls (e.g., System.arraycopy()
instead of
expensive loops.
ArrayList
,
Serialized FormAbstractReferenceList.ReferenceSubList<K>
Modifier and Type | Field and Description |
---|---|
static int |
DEFAULT_INITIAL_CAPACITY
The initial default capacity of an array list.
|
Constructor and Description |
---|
ReferenceArrayList()
Creates a new array list with
DEFAULT_INITIAL_CAPACITY capacity. |
ReferenceArrayList(java.util.Collection<? extends K> 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(java.util.Iterator<? extends K> i)
Creates a new array list and fills it with the elements returned by an iterator..
|
ReferenceArrayList(K[] a)
Creates a new array list and fills it with the elements of a given array.
|
ReferenceArrayList(K[] a,
int offset,
int length)
Creates a new array list and fills it with the elements of a given array.
|
ReferenceArrayList(ObjectIterator<? extends K> i)
Creates a new array list and fills it with the elements returned by a type-specific iterator..
|
ReferenceArrayList(ReferenceCollection<? extends K> c)
Creates a new array list and fills it with a given type-specific collection.
|
ReferenceArrayList(ReferenceList<? extends K> l)
Creates a new array list and fills it with a given type-specific list.
|
Modifier and Type | Method and Description |
---|---|
void |
add(int index,
K k) |
boolean |
add(K k) |
void |
addElements(int index,
K[] a,
int offset,
int length)
Adds elements to this type-specific list using optimized system calls.
|
void |
clear() |
ReferenceArrayList<K> |
clone() |
K[] |
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<K> l)
Compares this type-specific array list to another one.
|
K |
get(int index) |
void |
getElements(int from,
java.lang.Object[] a,
int offset,
int length)
Copies element of this type-specific list into the given array using optimized system calls.
|
int |
indexOf(java.lang.Object k) |
boolean |
isEmpty()
Checks whether the stack is empty.
|
int |
lastIndexOf(java.lang.Object k) |
ObjectListIterator<K> |
listIterator(int index)
Returns a type-specific list iterator on the list starting at a given index.
|
boolean |
rem(java.lang.Object k) |
K |
remove(int index) |
boolean |
remove(java.lang.Object o) |
void |
removeElements(int from,
int to)
Removes elements of this type-specific list using optimized system calls.
|
K |
set(int index,
K 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 <K> ReferenceArrayList<K> |
wrap(K[] a)
Wraps a given array into an array list.
|
static <K> ReferenceArrayList<K> |
wrap(K[] a,
int length)
Wraps a given array into an array list of given size.
|
addAll, addAll, addElements, contains, equals, hashCode, iterator, listIterator, objectListIterator, objectListIterator, peek, pop, push, referenceSubList, subList, top, toString
containsAll, objectIterator, removeAll, retainAll, toArray, toArray
containsAll, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray
objectIterator, toArray
public static final int DEFAULT_INITIAL_CAPACITY
public ReferenceArrayList(int capacity)
capacity
- the initial capacity of the array list (may be 0).public ReferenceArrayList()
DEFAULT_INITIAL_CAPACITY
capacity.public ReferenceArrayList(java.util.Collection<? extends K> c)
c
- a collection that will be used to fill the array list.public ReferenceArrayList(ReferenceCollection<? extends K> c)
c
- a type-specific collection that will be used to fill the array list.public ReferenceArrayList(ReferenceList<? extends K> l)
l
- a type-specific list that will be used to fill the array list.public ReferenceArrayList(K[] a)
a
- an array whose elements will be used to fill the array list.public ReferenceArrayList(K[] a, int offset, int length)
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.public ReferenceArrayList(java.util.Iterator<? extends K> i)
i
- an iterator whose returned elements will fill the array list.public ReferenceArrayList(ObjectIterator<? extends K> i)
i
- a type-specific iterator whose returned elements will fill the array list.public K[] elements()
If this array list was created by wrapping a given array, it is guaranteed
that the type of the returned array will be the same. Otherwise, the returned
array will be of type Object[]
(in spite of the declared return type).
Warning: This behaviour may cause (unfathomable)
run-time errors if a method expects an array
actually of type K[]
, but this methods returns an array
of type Object[]
.
public static <K> ReferenceArrayList<K> wrap(K[] a, int length)
a
- an array to wrap.length
- the length of the resulting array list.public static <K> ReferenceArrayList<K> wrap(K[] a)
a
- an array to wrap.public void ensureCapacity(int capacity)
capacity
- the new minimum capacity for this array list.public void add(int index, K k)
add
in interface java.util.List<K>
add
in class AbstractReferenceList<K>
public boolean add(K k)
add
in interface java.util.Collection<K>
add
in interface java.util.List<K>
add
in class AbstractReferenceList<K>
public int indexOf(java.lang.Object k)
indexOf
in interface java.util.List<K>
indexOf
in class AbstractReferenceList<K>
public int lastIndexOf(java.lang.Object k)
lastIndexOf
in interface java.util.List<K>
lastIndexOf
in class AbstractReferenceList<K>
public K remove(int index)
remove
in interface java.util.List<K>
remove
in class AbstractReferenceList<K>
public boolean rem(java.lang.Object k)
public boolean remove(java.lang.Object o)
public K set(int index, K k)
set
in interface java.util.List<K>
set
in class AbstractReferenceList<K>
public void clear()
public int size()
public void size(int size)
ReferenceList
If the specified size is smaller than the current size, the last elements are
discarded. Otherwise, they are filled with 0/null
/false
.
size
in interface ReferenceList<K>
size
in class AbstractReferenceList<K>
size
- the new size.public boolean isEmpty()
Stack
public void trim()
ArrayList.trimToSize()
public void trim(int n)
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.
n
- the threshold for the trimming.public void getElements(int from, java.lang.Object[] a, int offset, int length)
getElements
in interface ReferenceList<K>
getElements
in class AbstractReferenceList<K>
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.public void removeElements(int from, int to)
removeElements
in interface ReferenceList<K>
removeElements
in class AbstractReferenceList<K>
from
- the start index (inclusive).to
- the end index (exclusive).public void addElements(int index, K[] a, int offset, int length)
addElements
in interface ReferenceList<K>
addElements
in class AbstractReferenceList<K>
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.public ObjectListIterator<K> listIterator(int index)
ReferenceList
listIterator
in interface ReferenceList<K>
listIterator
in interface java.util.List<K>
listIterator
in class AbstractReferenceList<K>
List.listIterator(int)
public ReferenceArrayList<K> clone()
clone
in class java.lang.Object
public boolean equals(ReferenceArrayList<K> l)
This method exists only for sake of efficiency. The implementation inherited from the abstract implementation would already work.
l
- a type-specific array list.