it.unimi.dsi.fastutil.bytes
Class ByteArrayList

java.lang.Object
  extended by it.unimi.dsi.fastutil.bytes.AbstractByteCollection
      extended by it.unimi.dsi.fastutil.bytes.AbstractByteList
          extended by it.unimi.dsi.fastutil.bytes.ByteArrayList
All Implemented Interfaces:
ByteCollection, ByteIterable, ByteList, ByteStack, Stack<Byte>, Serializable, Cloneable, Comparable<List<? extends Byte>>, Iterable<Byte>, Collection<Byte>, List<Byte>, RandomAccess

public class ByteArrayList
extends AbstractByteList
implements RandomAccess, Cloneable, Serializable

A type-specific array-based list; provides some additional methods that use polymorphism to avoid (un)boxing.

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

Nested Class Summary
 
Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.bytes.AbstractByteList
AbstractByteList.ByteSubList
 
Field Summary
static int DEFAULT_INITIAL_CAPACITY
          The initial default capacity of an array list.
static long serialVersionUID
           
 
Constructor Summary
ByteArrayList()
          Creates a new array list with DEFAULT_INITIAL_CAPACITY capacity.
ByteArrayList(byte[] a)
          Creates a new array list and fills it with the elements of a given array.
ByteArrayList(byte[] a, int offset, int length)
          Creates a new array list and fills it with the elements of a given array.
ByteArrayList(ByteCollection c)
          Creates a new array list and fills it with a given type-specific collection.
ByteArrayList(ByteIterator i)
          Creates a new array list and fills it with the elements returned by a type-specific iterator..
ByteArrayList(ByteList l)
          Creates a new array list and fills it with a given type-specific list.
ByteArrayList(Collection<? extends Byte> c)
          Creates a new array list and fills it with a given collection.
ByteArrayList(int capacity)
          Creates a new array list with given capacity.
ByteArrayList(Iterator<? extends Byte> i)
          Creates a new array list and fills it with the elements returned by an iterator..
 
Method Summary
 boolean add(byte k)
           
 void add(int index, byte k)
           
 boolean addAll(int index, ByteCollection c)
          Delegates to a more generic method.
 boolean addAll(int index, ByteList l)
          Delegates to a more generic method.
 void addElements(int index, byte[] a, int offset, int length)
          Adds elements to this type-specific list using optimized system calls.
 void clear()
           
 Object clone()
           
 int compareTo(ByteArrayList l)
          Compares this list to another object.
 byte[] 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(ByteArrayList l)
          Compares this type-specific array list to another one.
 byte getByte(int index)
           
 void getElements(int from, byte[] a, int offset, int length)
          Copies element of this type-specific list into the given array using optimized system calls.
 int indexOf(byte k)
           
 boolean isEmpty()
          Checks whether the stack is empty.
 int lastIndexOf(byte k)
           
 ByteListIterator listIterator(int index)
          Returns a type-specific list iterator on the list starting at a given index.
 boolean rem(byte k)
          Note that this method should be called remove(), but the clash with the similarly named index-based method in the List interface forces us to use a distinguished name.
 byte removeByte(int index)
           
 void removeElements(int from, int to)
          Removes elements of this type-specific list using optimized system calls.
 byte set(int index, byte k)
           
 int size()
           
 void size(int size)
          Sets the size of this list.
 byte[] toByteArray(byte[] a)
          Returns a primitive type array containing the items of this collection.
 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 ByteArrayList wrap(byte[] a)
          Wraps a given array into an array list.
static ByteArrayList wrap(byte[] a, int length)
          Wraps a given array into an array list of given size.
 
Methods inherited from class it.unimi.dsi.fastutil.bytes.AbstractByteList
add, addAll, addAll, addAll, addAll, addElements, byteListIterator, byteListIterator, byteSubList, compareTo, contains, equals, get, hashCode, indexOf, iterator, lastIndexOf, listIterator, peek, peekByte, pop, popByte, push, push, remove, remove, set, subList, top, topByte, toString
 
Methods inherited from class it.unimi.dsi.fastutil.bytes.AbstractByteCollection
add, byteIterator, contains, containsAll, containsAll, rem, removeAll, removeAll, retainAll, retainAll, toArray, toArray, toArray, toByteArray
 
Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface java.util.List
add, contains, containsAll, removeAll, retainAll, toArray, toArray
 
Methods inherited from interface it.unimi.dsi.fastutil.bytes.ByteCollection
byteIterator, containsAll, removeAll, retainAll, toArray, toArray, toByteArray
 

Field Detail

serialVersionUID

public static final long serialVersionUID
See Also:
Constant Field Values

DEFAULT_INITIAL_CAPACITY

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

See Also:
Constant Field Values
Constructor Detail

ByteArrayList

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

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

ByteArrayList

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


ByteArrayList

public ByteArrayList(Collection<? extends Byte> 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.

ByteArrayList

public ByteArrayList(ByteCollection 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.

ByteArrayList

public ByteArrayList(ByteList 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.

ByteArrayList

public ByteArrayList(byte[] 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.

ByteArrayList

public ByteArrayList(byte[] 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.

ByteArrayList

public ByteArrayList(Iterator<? extends Byte> 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.

ByteArrayList

public ByteArrayList(ByteIterator 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 byte[] elements()
Returns the backing array of this list.

Returns:
the backing array.

wrap

public static ByteArrayList wrap(byte[] 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 ByteArrayList wrap(byte[] 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,
                byte k)
Specified by:
add in interface ByteList
Overrides:
add in class AbstractByteList
See Also:
List.add(int,Object)

add

public boolean add(byte k)
Specified by:
add in interface ByteCollection
Overrides:
add in class AbstractByteList
See Also:
Collection.add(Object)

getByte

public byte getByte(int index)
Specified by:
getByte in interface ByteList
See Also:
List.get(int)

indexOf

public int indexOf(byte k)
Specified by:
indexOf in interface ByteList
Overrides:
indexOf in class AbstractByteList
See Also:
List.indexOf(Object)

lastIndexOf

public int lastIndexOf(byte k)
Specified by:
lastIndexOf in interface ByteList
Overrides:
lastIndexOf in class AbstractByteList
See Also:
List.lastIndexOf(Object)

removeByte

public byte removeByte(int index)
Specified by:
removeByte in interface ByteList
Overrides:
removeByte in class AbstractByteList
See Also:
List.remove(int)

rem

public boolean rem(byte k)
Description copied from interface: ByteCollection
Note that this method should be called remove(), but the clash with the similarly named index-based method in the List interface forces us to use a distinguished name. For simplicity, the set interfaces reinstates remove().

Specified by:
rem in interface ByteCollection
Overrides:
rem in class AbstractByteList
See Also:
Collection.remove(Object)

set

public byte set(int index,
                byte k)
Specified by:
set in interface ByteList
Overrides:
set in class AbstractByteList
See Also:
List.set(int,Object)

clear

public void clear()
Specified by:
clear in interface Collection<Byte>
Specified by:
clear in interface List<Byte>
Overrides:
clear in class AbstractByteCollection

size

public int size()
Specified by:
size in interface Collection<Byte>
Specified by:
size in interface List<Byte>

size

public void size(int size)
Description copied from interface: ByteList
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 ByteList
Overrides:
size in class AbstractByteList
Parameters:
size - the new size.

isEmpty

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

Specified by:
isEmpty in interface Stack<Byte>
Specified by:
isEmpty in interface Collection<Byte>
Specified by:
isEmpty in interface List<Byte>
Overrides:
isEmpty in class AbstractByteCollection
Returns:
true if the stack is empty.

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,
                        byte[] 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 ByteList
Overrides:
getElements in class AbstractByteList
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 ByteList
Overrides:
removeElements in class AbstractByteList
Parameters:
from - the start index (inclusive).
to - the end index (exclusive).

addElements

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

Specified by:
addElements in interface ByteList
Overrides:
addElements in class AbstractByteList
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.

toByteArray

public byte[] toByteArray(byte[] a)
Description copied from interface: ByteCollection
Returns a primitive type array containing the items of this collection.

Note that, contrarily to Collection.toArray(Object[]), this methods just writes all elements of this collection: no special value will be added after the last one.

Specified by:
toByteArray in interface ByteCollection
Overrides:
toByteArray in class AbstractByteCollection
Parameters:
a - if this array is big enough, it will be used to store this collection.
Returns:
a primitive type array containing the items of this collection.
See Also:
Collection.toArray(Object[])

addAll

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

Specified by:
addAll in interface ByteList
Overrides:
addAll in class AbstractByteList
See Also:
List.add(int,Object)

addAll

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

Specified by:
addAll in interface ByteList
Overrides:
addAll in class AbstractByteList
See Also:
List.add(int,Object)

listIterator

public ByteListIterator listIterator(int index)
Description copied from interface: ByteList
Returns a type-specific list iterator on the list starting at a given index.

Specified by:
listIterator in interface ByteList
Specified by:
listIterator in interface List<Byte>
Overrides:
listIterator in class AbstractByteList
See Also:
ByteList.listIterator(int)

clone

public Object clone()
Overrides:
clone in class Object

equals

public boolean equals(ByteArrayList 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.

compareTo

public int compareTo(ByteArrayList l)
Compares this list to another object. If the argument is a List, this method performs a lexicographical comparison; otherwise, it throws a ClassCastException.

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

Parameters:
l - an list.
Returns:
if the argument is a List, a negative integer, zero, or a positive integer as this list is lexicographically less than, equal to, or greater than the argument.
Throws:
ClassCastException - if the argument is not a list.