de.vc.util

Class SwappingList<T>

java.lang.Object

de.vc.util.SwappingList<T>

All Implemented Interfaces:

java.lang.Iterable<T>, java.util.Collection<T>, java.util.List<T>

public class SwappingList<T>
extends java.lang.Object
implements java.util.List<T>

The SwappingList can swap objects at begin of this list into a temporary file to reduce memory consumption.

Constructor Summary

Constructors

Constructor and Description
SwappingList() Constructs a new swapping list.
SwappingList(int max, int keep) Constructs a new swapping list.

Method Summary

Modifier and Type	Method and Description
void	add(int index, T element)
boolean	add(T o)
boolean	addAll(java.util.Collection<? extends T> c)
boolean	addAll(int index, java.util.Collection<? extends T> c)
void	clear()
boolean	contains(java.lang.Object o) Returns true if this list contains the specified element.
boolean	containsAll(java.util.Collection<?> c)
boolean	equals(java.lang.Object o)
T	get(int index) Gets an object of this list.
int	getKeepMemoryEntries() Gets the number of (last) objects that are keeped in memory when objects are swapped to disc.
int	getMaxMemoryEntries() Sets the maximum number of (last) objects that are hold in memory.
int	getMemoryIndex() Gets the index of first element that is in memory.
java.io.File	getPageFile() Gets the page-file of this swapping list.
int	hashCode()
int	indexOf(java.lang.Object o)
boolean	isEmpty() Returns true if this list contains no elements.
java.util.Iterator<T>	iterator()
int	lastIndexOf(java.lang.Object o)
java.util.ListIterator<T>	listIterator()
java.util.ListIterator<T>	listIterator(int index)
T	remove(int index)
boolean	remove(java.lang.Object o)
boolean	removeAll(java.util.Collection<?> c)
boolean	retainAll(java.util.Collection<?> c)
T	set(int index, T element) Sets the object at a given position.
void	setKeepMemoryEntries(int keep) Sets the number of (last) objects that are keeped in memory when objects are swapped to disc.
void	setMaxMemoryEntries(int max) Sets the maximum number of (last) objects that are hold in memory.
int	size()
java.util.List<T>	subList(int fromIndex, int toIndex)
void	swapAll() Swaps all elements that are still in memory to disc.
java.lang.Object[]	toArray()
java.lang.Object[]	toArray(java.lang.Object[] a)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.List

replaceAll, sort, spliterator

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

SwappingList

public SwappingList()

Constructs a new swapping list.

SwappingList

public SwappingList(int max,
                    int keep)

Constructs a new swapping list.

Parameters:

max - Maximum number of objects in memory.

keep - Number of objects keeped in memory when swapped to disc.

Method Detail

getMemoryIndex

public int getMemoryIndex()

Gets the index of first element that is in memory. All elements with an lower index are stored in a temporary page file.

Returns:

Index of first element that is in memory.

setMaxMemoryEntries

public void setMaxMemoryEntries(int max)

Sets the maximum number of (last) objects that are hold in memory. If value is less then 1, all objects are hold in memory and no objects are swapped to disc.

Parameters:

max - Maximum number of objects in memory.

getMaxMemoryEntries

public int getMaxMemoryEntries()

Sets the maximum number of (last) objects that are hold in memory. If value is less then 1, all objects are hold in memory and no objects are swapped to disc.

Returns:

Maximum number of objects.

setKeepMemoryEntries

public void setKeepMemoryEntries(int keep)

Sets the number of (last) objects that are keeped in memory when objects are swapped to disc. Must be between 0 and (maximum number of objects - 1).

Parameters:

keep - Number of objects keeped in memory when swapped to disc.

getKeepMemoryEntries

public int getKeepMemoryEntries()

Gets the number of (last) objects that are keeped in memory when objects are swapped to disc.

Returns:

Number of objects keeped in memory after swapping.

getPageFile

public java.io.File getPageFile()

Gets the page-file of this swapping list. If no page file is created, NULL is returned.

Returns:

Page file of this list.

swapAll

public void swapAll()

Swaps all elements that are still in memory to disc.

size

public int size()

Specified by:

size in interface java.util.Collection<T>

Specified by:

size in interface java.util.List<T>

isEmpty

public boolean isEmpty()

Returns true if this list contains no elements.

Specified by:

isEmpty in interface java.util.Collection<T>

Specified by:

isEmpty in interface java.util.List<T>

Returns:

true if this list contains no elements.

contains

public boolean contains(java.lang.Object o)

Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that (o==null ? e==null : o.equals(e)).

Specified by:

contains in interface java.util.Collection<T>

Specified by:

contains in interface java.util.List<T>

Parameters:

o - element whose presence in this list is to be tested.

Returns:

true if this list contains the specified element.

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T>

Specified by:

iterator in interface java.util.Collection<T>

Specified by:

iterator in interface java.util.List<T>

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<T>

Specified by:

toArray in interface java.util.List<T>

toArray

public java.lang.Object[] toArray(java.lang.Object[] a)

Specified by:

toArray in interface java.util.Collection<T>

Specified by:

toArray in interface java.util.List<T>

add

public boolean add(T o)

Specified by:

add in interface java.util.Collection<T>

Specified by:

add in interface java.util.List<T>

remove

public boolean remove(java.lang.Object o)

Specified by:

remove in interface java.util.Collection<T>

Specified by:

remove in interface java.util.List<T>

containsAll

public boolean containsAll(java.util.Collection<?> c)

Specified by:

containsAll in interface java.util.Collection<T>

Specified by:

containsAll in interface java.util.List<T>

addAll

public boolean addAll(java.util.Collection<? extends T> c)

Specified by:

addAll in interface java.util.Collection<T>

Specified by:

addAll in interface java.util.List<T>

addAll

public boolean addAll(int index,
                      java.util.Collection<? extends T> c)

Specified by:

addAll in interface java.util.List<T>

removeAll

public boolean removeAll(java.util.Collection<?> c)

Specified by:

removeAll in interface java.util.Collection<T>

Specified by:

removeAll in interface java.util.List<T>

retainAll

public boolean retainAll(java.util.Collection<?> c)

Specified by:

retainAll in interface java.util.Collection<T>

Specified by:

retainAll in interface java.util.List<T>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<T>

Specified by:

clear in interface java.util.List<T>

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Collection<T>

Specified by:

equals in interface java.util.List<T>

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Collection<T>

Specified by:

hashCode in interface java.util.List<T>

Overrides:

hashCode in class java.lang.Object

get

public T get(int index)

Gets an object of this list. Note, if the object is already swapped to disc any modification to the object are not stored to swap-file! To check, if the object is swapped to disc you can use getMemoryIndex().

Specified by:

get in interface java.util.List<T>

Parameters:

index - Index of object.

Returns:

Object

Throws:

java.lang.IndexOutOfBoundsException - is thrown if index is invalid.

set

public T set(int index,
             T element)

Sets the object at a given position. Note, you can't set elements that are already swapped to disc.

Specified by:

set in interface java.util.List<T>

Parameters:

index - Index of element.

element - Element.

Returns:

Old element.

Throws:

java.lang.IndexOutOfBoundsException - is thrown if index is invalid.

add

public void add(int index,
                T element)

Specified by:

add in interface java.util.List<T>

remove

public T remove(int index)

Specified by:

remove in interface java.util.List<T>

indexOf

public int indexOf(java.lang.Object o)

Specified by:

indexOf in interface java.util.List<T>

lastIndexOf

public int lastIndexOf(java.lang.Object o)

Specified by:

lastIndexOf in interface java.util.List<T>

listIterator

public java.util.ListIterator<T> listIterator()

Specified by:

listIterator in interface java.util.List<T>

listIterator

public java.util.ListIterator<T> listIterator(int index)

Specified by:

listIterator in interface java.util.List<T>

subList

public java.util.List<T> subList(int fromIndex,
                                 int toIndex)

Specified by:

subList in interface java.util.List<T>