com.scaleoutsoftware.soss.client

Class IndexCollection

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractList<IndexValue>

com.scaleoutsoftware.soss.client.IndexCollection

All Implemented Interfaces:

Externalizable, Serializable, Iterable<IndexValue>, Collection<IndexValue>, List<IndexValue>

public final class IndexCollection
extends AbstractList<IndexValue>
implements List<IndexValue>, Externalizable

A List of IndexValues which may be used to query the StateServer object store for the set of objects with metadata matching the (positional) values specified in the IndexCollection.

IndexCollections are fixed-length Lists where the length is defined by the StateServer implementation. Not all index positions need have values. That is, an IndexCollection may be sparsely filled in.

Since the index position of an item in an IndexCollection is semantically key, this List implementation does not support List.add(E) or List.remove(java.lang.Object) operations. It does support List.clear() by resetting the value in all index positions to null. Similarly, it supports selective clearing via clearRange(int, int).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	MaxIndexValues The fixed number of IndexValues an IndexCollection may hold.

Constructor Summary

Constructors

Constructor and Description
IndexCollection()

Method Summary

Modifier and Type	Method and Description
boolean	add(IndexValue o) Adding to the end of an IndexCollection is not supported.
void	add(int index, IndexValue element) Inserts the specified IndexValue at the specified position in this list.
void	clear() Clears all elements in the IndexCollection by setting the IndexValue in each index position to null.
void	clearRange(int fromIndex, int toIndex) Clears a range of elements in the IndexCollection by setting the IndexValues in the corresponding index positions to null.
IndexValue	get(int index) Gets the element at the specified index.
boolean	isEmpty() Returns true if this IndexCollection contains no (non-null) IndexValues.
void	readExternal(ObjectInput in)
IndexValue	remove(int index) Removes the element at the specified index of the IndexCollection.
IndexValue	set(int index, IndexValue element) Replaces the element at the specified position in this list with the specified element (optional operation).
int	size() Gets the number of elements in the IndexCollection.
void	writeExternal(ObjectOutput out)

Methods inherited from class java.util.AbstractList

addAll, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.List

addAll, addAll, contains, containsAll, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeAll, replaceAll, retainAll, sort, spliterator, subList, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

MaxIndexValues

public static final int MaxIndexValues

The fixed number of IndexValues an IndexCollection may hold. This value is currently 8.

See Also:

Constant Field Values

Constructor Detail

IndexCollection

public IndexCollection()

Method Detail

get

public IndexValue get(int index)

Gets the element at the specified index.

If no element has been assigned to a given index position, the get operation will return null.

Specified by:

get in interface List<IndexValue>

Specified by:

get in class AbstractList<IndexValue>

Parameters:

index - The index of the element to get or set.

Returns:

the element at the specified index, or null if no element has been assigned to the given index position.

Throws:

IndexOutOfBoundsException - if the index is out of range (index < 0 or index >= size()).

set

public IndexValue set(int index,
                      IndexValue element)

Replaces the element at the specified position in this list with the specified element (optional operation).

Specified by:

set in interface List<IndexValue>

Overrides:

set in class AbstractList<IndexValue>

Parameters:

index - the index of element to replace.

element - the IndexValue to be stored at the specified position.

Returns:

the IndexValue previously at the specified position.

Throws:

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

size

public int size()

Gets the number of elements in the IndexCollection. Since the collection is fixed-size, this method always returns MaxIndexValues.

Specified by:

size in interface Collection<IndexValue>

Specified by:

size in interface List<IndexValue>

Specified by:

size in class AbstractCollection<IndexValue>

Returns:

always returns MaxIndexValues

clear

public void clear()

Clears all elements in the IndexCollection by setting the IndexValue in each index position to null.

Specified by:

clear in interface Collection<IndexValue>

Specified by:

clear in interface List<IndexValue>

Overrides:

clear in class AbstractList<IndexValue>

clearRange

public void clearRange(int fromIndex,
                       int toIndex)

Clears a range of elements in the IndexCollection by setting the IndexValues in the corresponding index positions to null.

The range to be cleared extends from index fromIndex, inclusive, to index toIndex, exclusive. (If fromIndex==toIndex, the range to be cleared is empty.)

Parameters:

fromIndex - the index of the first element (inclusive) to be cleared.

toIndex - the index of the last element (exclusive) to be cleared.

Throws:

IllegalArgumentException - if fromIndex > toIndex

ArrayIndexOutOfBoundsException - if fromIndex < 0 or toIndex > size()

isEmpty

public boolean isEmpty()

Returns true if this IndexCollection contains no (non-null) IndexValues.

Specified by:

isEmpty in interface Collection<IndexValue>

Specified by:

isEmpty in interface List<IndexValue>

Overrides:

isEmpty in class AbstractCollection<IndexValue>

Returns:

true if this IndexCollection contains no (non-null) IndexValues. Otherwise, false.

remove

public IndexValue remove(int index)

Removes the element at the specified index of the IndexCollection. All elements in the list following the removed element are moved 1 position to the left. The element at MaxIndexValues - 1 is set to null.

Specified by:

remove in interface List<IndexValue>

Overrides:

remove in class AbstractList<IndexValue>

Parameters:

index - The zero-based index of the element to remove.

add

public void add(int index,
                IndexValue element)
         throws IndexOutOfBoundsException

Inserts the specified IndexValue at the specified position in this list. Shifts the element currently at that position and any subsequent elements to the right (adds one to their indices). The element at position MaxIndexValues-1 is removed from the collection.

Since IndexCollections are fixed-length Lists, index must be less than size().

Specified by:

add in interface List<IndexValue>

Overrides:

add in class AbstractList<IndexValue>

Parameters:

index - index at which the specified element is to be inserted.

element - the IndexValue to be inserted.

Throws:

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

add

public boolean add(IndexValue o)

Adding to the end of an IndexCollection is not supported.

Specified by:

add in interface Collection<IndexValue>

Specified by:

add in interface List<IndexValue>

Overrides:

add in class AbstractList<IndexValue>

Throws:

UnsupportedOperationException - when adding to the end of the IndexCollection

See Also:

add(int, IndexValue)

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException