de.learnlib.filters.reuse.tree

Class BoundedDeque<E>

java.lang.Object

java.util.AbstractCollection<E>

de.learnlib.filters.reuse.tree.BoundedDeque<E>

Type Parameters:

E - element type

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>

public class BoundedDeque<E>
extends AbstractCollection<E>
implements Serializable

A generic deque-derived container which transparently acts either as a stack or a queue, and optionally a capacity restriction with a configurable policy which element is evicted (or reject) if the maximum capacity is reached.

Note: Like ArrayDeque, this deque implementation is not thread-safe. Concurrent access by multiple threads requires explicit synchronization.

Author:

Malte Isberner

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BoundedDeque.AccessPolicy The policy which determines in which order elements are accessed.
static class	BoundedDeque.EvictPolicy The policy which determines in which order elements are removed if the maximum capacity is reached.

Constructor Summary

Constructors

Constructor and Description
BoundedDeque(BoundedDeque.AccessPolicy accessPolicy) Constructor.
BoundedDeque(int capacity, BoundedDeque.AccessPolicy accessPolicy, BoundedDeque.EvictPolicy evictPolicy) Constructor.

Method Summary

Modifier and Type	Method and Description
void	clear()
E	insert(E element) Inserts an element into the deque, and returns the one that had to be evicted in case of a capacity violation.
boolean	isBounded() Retrieves whether capacity restriction is in effect.
boolean	isEmpty()
Iterator<E>	iterator()
E	peek() Retrieves, but does not remove the top-most element, i.e., the element that is either the top of the stack or the head of the queue, depending on the configured BoundedDeque.AccessPolicy.
E	retrieve() Retrieves and remove the top-most element, i.e., the element that is either the top of the stack or the head of the queue, depending on the configured BoundedDeque.AccessPolicy.
int	size()

Methods inherited from class java.util.AbstractCollection

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

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

equals, hashCode, parallelStream, removeIf, spliterator, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

BoundedDeque

public BoundedDeque(BoundedDeque.AccessPolicy accessPolicy)

Constructor. Creates an unbounded deque with the given access policy.

Parameters:

accessPolicy - whether this deque acts as a stack or a queue

BoundedDeque

public BoundedDeque(int capacity,
                    BoundedDeque.AccessPolicy accessPolicy,
                    BoundedDeque.EvictPolicy evictPolicy)

Constructor. Creates a possibly capacity-restricted deque with the given access policy.

Parameters:

capacity - the maximum capacity of this deque. A value less than or equal to 0 means unbounded

accessPolicy - whether this deque acts as a stack or a queue

evictPolicy - which elements to remove if the maximum capacity is reached. If the capacity is unbounded, this parameter has no effect

Method Detail

insert

public E insert(E element)

Inserts an element into the deque, and returns the one that had to be evicted in case of a capacity violation.

Parameters:

element - the element to insert

Returns:

the evicted element, null if the maximum capacity has not been reached

retrieve

public E retrieve()

Retrieves and remove the top-most element, i.e., the element that is either the top of the stack or the head of the queue, depending on the configured BoundedDeque.AccessPolicy.

Returns:

the top-most element of the container

peek

public E peek()

Retrieves, but does not remove the top-most element, i.e., the element that is either the top of the stack or the head of the queue, depending on the configured BoundedDeque.AccessPolicy.

Returns:

the top-most element of the container

isBounded

public boolean isBounded()

Retrieves whether capacity restriction is in effect.

Returns:

true if the capacity is restricted, false otherwise

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Collection<E>

Overrides:

isEmpty in class AbstractCollection<E>

size

public int size()

Specified by:

size in interface Collection<E>

Specified by:

size in class AbstractCollection<E>

clear

public void clear()

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollection<E>

iterator

public Iterator<E> iterator()

Specified by:

iterator in interface Iterable<E>

Specified by:

iterator in interface Collection<E>

Specified by:

iterator in class AbstractCollection<E>