ptolemy.backtrack.util.java.util

Class AbstractSequentialList

java.lang.Object

ptolemy.backtrack.util.java.util.AbstractCollection

ptolemy.backtrack.util.java.util.AbstractList

ptolemy.backtrack.util.java.util.AbstractSequentialList

All Implemented Interfaces:

Rollbackable, Collection, List

Direct Known Subclasses:

LinkedList

public abstract class AbstractSequentialList
extends AbstractList
implements Rollbackable

Abstract superclass to make it easier to implement the List interface when backed by a sequential-access store, such as a linked list. For random access data, use AbstractList. This class implements the random access methods (get, set, add, and remove) atop the list iterator, opposite of AbstractList's approach of implementing the iterator atop random access.

To implement a list, you need an implementation for size() and listIterator. With just hasNext, next, hasPrevious, previous, nextIndex, and previousIndex, you have an unmodifiable list. For a modifiable one, add set, and for a variable-size list, add add and remove.

The programmer should provide a no-argument constructor, and one that accepts another Collection, as recommended by the Collection interface. Unfortunately, there is no way to enforce this in Java.

Since:

1.2

Author:

Original author unknown, Bryce McKinlay, Eric Blake (ebb9@email.byu.edu)

See Also:

Collection, List, AbstractList, AbstractCollection, ListIterator, LinkedList

Status

updated to 1.4

Field Summary

Fields inherited from class ptolemy.backtrack.util.java.util.AbstractCollection

$CHECKPOINT, $RECORD$$CHECKPOINT

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSequentialList() The main constructor, for use by subclasses.

Method Summary

Modifier and Type	Method and Description
void	$COMMIT(long timestamp) Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.
void	$RESTORE(long timestamp, boolean trim) Restore a previous state to all the private fields of this rollbackable object.
void	add(int index, java.lang.Object o) Insert an element into the list at a given position (optional operation).
boolean	addAll(int index, Collection c) Insert the contents of a collection into the list at a given position (optional operation).
java.lang.Object	get(int index) Get the element at a given index in this list.
java.util.Iterator	iterator() Obtain an Iterator over this list, whose sequence is the list order.
abstract java.util.ListIterator	listIterator(int index) Returns a ListIterator over the list, starting from position index.
java.lang.Object	remove(int index) Remove the element at a given position in this list (optional operation).
java.lang.Object	set(int index, java.lang.Object o) Replace an element of this list with another object (optional operation).

Methods inherited from class ptolemy.backtrack.util.java.util.AbstractList

add, clear, equals, getModCount, hashCode, indexOf, lastIndexOf, listIterator, removeRange, setModCount, subList

Methods inherited from class ptolemy.backtrack.util.java.util.AbstractCollection

$GET$CHECKPOINT, $SET$CHECKPOINT, addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface ptolemy.backtrack.Rollbackable

$GET$CHECKPOINT, $SET$CHECKPOINT

Methods inherited from interface ptolemy.backtrack.util.java.util.List

$GET$CHECKPOINT, $SET$CHECKPOINT, addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, toArray, toArray

Constructor Detail

AbstractSequentialList

protected AbstractSequentialList()

The main constructor, for use by subclasses.

Method Detail

listIterator

public abstract java.util.ListIterator listIterator(int index)

Returns a ListIterator over the list, starting from position index. Subclasses must provide an implementation of this method.

Specified by:

listIterator in interface List

Overrides:

listIterator in class AbstractList

Parameters:

index - the starting position of the list

Returns:

the list iterator

Throws:

java.lang.IndexOutOfBoundsException - if index < 0 || index > size()

See Also:

AbstractList.modCount

add

public void add(int index,
                java.lang.Object o)

Insert an element into the list at a given position (optional operation). This shifts all existing elements from that position to the end one index to the right. This version of add has no return, since it is assumed to always succeed if there is no exception. This iteration uses listIterator(index).add(o).

Specified by:

add in interface List

Overrides:

add in class AbstractList

Parameters:

index - the location to insert the item

o - the object to insert

Throws:

java.lang.UnsupportedOperationException - if this list does not support the add operation

java.lang.IndexOutOfBoundsException - if index < 0 || index > size()

java.lang.ClassCastException - if o cannot be added to this list due to its type

java.lang.IllegalArgumentException - if o cannot be added to this list for some other reason.

java.lang.NullPointerException - if o is null and the list does not permit the addition of null values.

See Also:

AbstractList.modCount

addAll

public boolean addAll(int index,
                      Collection c)

Insert the contents of a collection into the list at a given position (optional operation). Shift all elements at that position to the right by the number of elements inserted. This operation is undefined if this list is modified during the operation (for example, if you try to insert a list into itself).

This implementation grabs listIterator(index), then proceeds to use add for each element returned by c's iterator. Sun's online specs are wrong, claiming that this also calls next(): listIterator.add() correctly skips the added element.

Specified by:

addAll in interface List

Overrides:

addAll in class AbstractList

Parameters:

index - the location to insert the collection

c - the collection to insert

Returns:

true if the list was modified by this action, that is, if c is non-empty

Throws:

java.lang.UnsupportedOperationException - if this list does not support the addAll operation

java.lang.IndexOutOfBoundsException - if index < 0 || index > size()

java.lang.ClassCastException - if some element of c cannot be added to this list due to its type

java.lang.IllegalArgumentException - if some element of c cannot be added to this list for some other reason

java.lang.NullPointerException - if the specified collection is null

java.lang.NullPointerException - if an object, o, in c is null and the list does not permit the addition of null values.

See Also:

add(int, Object)

get

public java.lang.Object get(int index)

Get the element at a given index in this list. This implementation returns listIterator(index).next().

Specified by:

get in interface List

Specified by:

get in class AbstractList

Parameters:

index - the index of the element to be returned

Returns:

the element at index index in this list

Throws:

java.lang.IndexOutOfBoundsException - if index < 0 || index >= size()

iterator

public java.util.Iterator iterator()

Obtain an Iterator over this list, whose sequence is the list order. This implementation returns listIterator().

Specified by:

iterator in interface Collection

Specified by:

iterator in interface List

Overrides:

iterator in class AbstractList

Returns:

an Iterator over the elements of this list, in order

See Also:

AbstractList.modCount

remove

public java.lang.Object remove(int index)

Remove the element at a given position in this list (optional operation). Shifts all remaining elements to the left to fill the gap. This implementation uses listIterator(index) and ListIterator.remove().

Specified by:

remove in interface List

Overrides:

remove in class AbstractList

Parameters:

index - the position within the list of the object to remove

Returns:

the object that was removed

Throws:

java.lang.UnsupportedOperationException - if this list does not support the remove operation

java.lang.IndexOutOfBoundsException - if index < 0 || index >= size()

See Also:

AbstractList.modCount

set

public java.lang.Object set(int index,
                            java.lang.Object o)

Replace an element of this list with another object (optional operation). This implementation uses listIterator(index) and ListIterator.set(o).

Specified by:

set in interface List

Overrides:

set in class AbstractList

Parameters:

index - the position within this list of the element to be replaced

o - the object to replace it with

Returns:

the object that was replaced

Throws:

java.lang.UnsupportedOperationException - if this list does not support the set operation

java.lang.IndexOutOfBoundsException - if index < 0 || index >= size()

java.lang.ClassCastException - if o cannot be added to this list due to its type

java.lang.IllegalArgumentException - if o cannot be added to this list for some other reason

java.lang.NullPointerException - if o is null and the list does not allow a value to be set to null.

$COMMIT

public void $COMMIT(long timestamp)

Description copied from interface: Rollbackable

Commit changes up to the given timestamp, but not including changes made at timestamp and afterward.

Specified by:

$COMMIT in interface Rollbackable

Specified by:

$COMMIT in interface Collection

Specified by:

$COMMIT in interface List

Overrides:

$COMMIT in class AbstractList

Parameters:

timestamp - The timestamp.

$RESTORE

public void $RESTORE(long timestamp,
                     boolean trim)

Description copied from interface: Rollbackable

Restore a previous state to all the private fields of this rollbackable object.

Specified by:

$RESTORE in interface Rollbackable

Specified by:

$RESTORE in interface Collection

Specified by:

$RESTORE in interface List

Overrides:

$RESTORE in class AbstractList

Parameters:

timestamp - The timestamp taken at the time when the previous state was recorded.

trim - Whether to delete the records used for the rollback.

See Also:

Checkpoint.rollback(long, boolean)