An unbounded priority queue based on a binary heap algorithm. More...

#include <src/main/decaf/util/PriorityQueue.h>

Inheritance diagram for decaf::util::PriorityQueue< E >:

Data Structures
class	ConstPriorityQueueIterator
class	PriorityQueueIterator

Public Member Functions

PriorityQueue ()

Creates a Priority Queue with the default initial capacity.

PriorityQueue (int initialCapacity)

Creates a Priority Queue with the capacity value supplied.

PriorityQueue (int initialCapacity, Comparator< E > *comparator)

Creates a Priority Queue with the default initial capacity.

PriorityQueue (const Collection< E > &source)

Creates a PriorityQueue containing the elements in the specified Collection.

PriorityQueue (const PriorityQueue< E > &source)

Creates a PriorityQueue containing the elements in the specified priority queue.

virtual ~PriorityQueue ()

PriorityQueue< E > & operator= (const Collection< E > &source)

Assignment operator, assign another Collection to this one.

PriorityQueue< E > & operator= (const PriorityQueue< E > &source)

Assignment operator, assign another PriorityQueue to this one.

virtual decaf::util::Iterator
< E > * iterator ()

virtual decaf::util::Iterator
< E > * iterator () const

virtual int size () const

virtual void clear ()

virtual bool offer (const E &value)

virtual bool poll (E &result)

virtual bool peek (E &result) const

virtual E remove ()

virtual bool remove (const E &value)

virtual bool add (const E &value)

decaf::lang::Pointer
< Comparator< E > > comparator () const

obtains a Copy of the Pointer instance that this PriorityQueue is using to compare the elements in the queue with.

Public Member Functions inherited from decaf::util::AbstractQueue< E >

AbstractQueue ()

virtual ~AbstractQueue ()

virtual bool add (const E &value)

Returns true if this collection changed as a result of the call.(Returns false if this collection does not permit duplicates and already contains the specified element.)Collections that support this operation may place limitations on what elements may be added to this collection. In particular, some collections will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. Collection classes should clearly specify in their documentation any restrictions on what elements may be added.If a collection refuses to add a particular element for any reason other than that it already contains the element, it must throw an exception (rather than returning false). This preserves the invariant that a collection always contains the specified element after this call returns.For non-pointer values, i.e. class instances or string's the object will be copied into the collection, thus the object must support being copied, must not hide the copy constructor and assignment operator.

Parameters

value The reference to the element to add to this Collection.

Returns: true if the element was added to this Collection.

Exceptions

UnsupportedOperationExceptio	if this is an unmodifiable collection.
NullPointerException	if the Collection is a container of pointers and does not allow NULL values.
IllegalArgumentException	if some property of the element prevents it from being added to this collection
IllegalStateException	if the element cannot be added at this time due to insertion restrictions.

virtual bool addAll (const Collection< E > &collection)

Adds all of the elements in the specified collection to this collection.The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified collection is this collection, and this collection is nonempty.)

Parameters

collection The Collection whose elements are added to this one.

Returns: true if this collection changed as a result of the call

Exceptions

UnsupportedOperationExceptio	if this is an unmodifiable collection.
NullPointerException	if the Collection is a container of pointers and does not allow NULL values.
IllegalArgumentException	if some property of an element prevents it from being added to this collection
IllegalStateException	if an element cannot be added at this time due to insertion restrictions.

This implementation iterates over the specified collection, and adds each object returned by the iterator to this collection, in turn.Note that this implementation will throw an UnsupportedOperationException unless add is overridden (assuming the specified collection is non-empty).

virtual E remove ()

Gets and removes the element in the head of the queue.Throws a NoSuchElementException if there is no element in the queue.

Returns: the element in the head of the queue.

Exceptions

NoSuchElementException if there is no element in the queue.

virtual E element () const

Gets but not removes the element in the head of the queue.Throws a NoSuchElementException if there is no element in the queue.

Returns: the element in the head of the queue.

Exceptions

NoSuchElementException if there is no element in the queue.

virtual void clear ()

Removes all of the elements from this collection (optional operation).The collection will be empty after this method returns.This implementation iterates over this collection, removing each element using the Iterator.remove operation. Most implementations will probably choose to override this method for efficiency.Note that this implementation will throw an UnsupportedOperationException if the iterator returned by this collection's iterator method does not implement the remove method and this collection is non-empty.

Exceptions

UnsupportedOperationException if the clear operation is not supported by this collection

Public Member Functions inherited from decaf::util::Queue< E >

virtual ~Queue ()

virtual bool offer (const E &value)=0

Inserts the specified element into the queue provided that the condition allows such an operation.

virtual bool poll (E &result)=0

Gets and removes the element in the head of the queue.

virtual bool peek (E &result) const =0

Gets but not removes the element in the head of the queue.

Public Member Functions inherited from decaf::util::Collection< E >

virtual ~Collection ()

virtual int size () const =0

Returns the number of elements in this collection.

Public Member Functions inherited from decaf::lang::Iterable< E >

virtual ~Iterable ()

virtual decaf::util::Iterator
< E > * iterator ()=0

virtual decaf::util::Iterator
< E > * iterator () const =0

Public Member Functions inherited from decaf::util::concurrent::Synchronizable

virtual ~Synchronizable ()

Public Member Functions inherited from decaf::util::AbstractCollection< E >

AbstractCollection ()

virtual ~AbstractCollection ()

AbstractCollection< E > & operator= (const AbstractCollection< E > &collection)

Assignment Operator, copy element from the source collection to this collection after clearing any element stored in this collection.

virtual bool contains (const E &value) const

Returns true if this collection contains the specified element.More formally, returns true if and only if this collection contains at least one element e such that (value == NULL ? e == NULL : value == e ).

Parameters

value The value to check for presence in the collection.

Returns: true if there is at least one of the elements in the collection

Exceptions

NullPointerException if the Collection contains pointers and the Collection does not allow for NULL elements (optional check).

virtual bool containsAll (const Collection< E > &collection) const

Returns true if this collection contains all of the elements in the specified collection.

Parameters

collection The Collection to compare to this one.

Exceptions

NullPointerException if the Collection contains pointers and the Collection does not allow for NULL elements (optional check).

virtual bool equals (const Collection< E > &collection) const

Answers true if this Collection and the one given are the same size and if each element contained in the Collection given is equal to an element contained in this collection.

virtual void copy (const Collection< E > &collection)

Renders this Collection as a Copy of the given Collection.

virtual bool isEmpty () const

Returns true if this collection contains no elements.

virtual bool add (const E &value DECAF_UNUSED)

virtual bool remove (const E &value)

Removes a single instance of the specified element from the collection.More formally, removes an element e such that (value == NULL ? e == NULL : value == e), if this collection contains one or more such elements. Returns true if this collection contained the specified element (or equivalently, if this collection changed as a result of the call).

Parameters

value The reference to the element to remove from this Collection.

Returns: true if the collection was changed, false otherwise.

Exceptions

UnsupportedOperationExceptio	if this is an unmodifiable collection.
NullPointerException	if the Collection is a container of pointers and does not allow NULL values.

virtual bool removeAll (const Collection< E > &collection)

Removes all this collection's elements that are also contained in the specified collection (optional operation).After this call returns, this collection will contain no elements in common with the specified collection.

Parameters

collection The Collection whose elements are to be removed from this one.

Returns: true if the collection changed as a result of this call.

Exceptions

UnsupportedOperationExceptio	if this is an unmodifiable collection.
NullPointerException	if the Collection is a container of pointers and does not allow NULL values.

virtual bool retainAll (const Collection< E > &collection)

Retains only the elements in this collection that are contained in the specified collection (optional operation).In other words, removes from this collection all of its elements that are not contained in the specified collection.

Parameters

collection The Collection whose elements are to be retained.

Returns: true if the collection changed as a result of this call.

Exceptions

UnsupportedOperationExceptio	if this is an unmodifiable collection.
NullPointerException	if the Collection is a container of pointers and does not allow NULL values.

virtual std::vector< E > toArray () const

Answers an STL vector containing copies of all elements contained in this Collection.

virtual void lock ()

Locks the object.

virtual bool tryLock ()

Attempts to Lock the object, if the lock is already held by another thread than this method returns false.

virtual void unlock ()

Unlocks the object.

virtual void wait ()

Waits on a signal from this object, which is generated by a call to Notify.

virtual void wait (long long millisecs)

Waits on a signal from this object, which is generated by a call to Notify.

virtual void wait (long long millisecs, int nanos)

Waits on a signal from this object, which is generated by a call to Notify.

virtual void notify ()

Signals a waiter on this object that it can now wake up and continue.

virtual void notifyAll ()

Signals the waiters on this object that it can now wake up and continue.

Friends
class	PriorityQueueIterator

Additional Inherited Members
Protected Attributes inherited from decaf::util::AbstractCollection< E >
util::concurrent::Mutex	mutex

Detailed Description

template<typename E>
class decaf::util::PriorityQueue< E >

An unbounded priority queue based on a binary heap algorithm.

The elements of the priority queue are ordered according to their natural ordering, or by a Comparator provided to one of the constructors that accepts Comparators. A priority queue relying on natural ordering also does not permit insertion of non-comparable objects (doing so may result in a compiler error).

The head of this queue is the least element with respect to the specified ordering. If multiple elements are tied for least value, the head is one of those elements – ties are broken arbitrarily. The queue retrieval operations poll, remove, peek, and element access the element at the head of the queue.

A priority queue is unbounded, but has an internal capacity governing the size of an array used to store the elements on the queue. It is always at least as large as the queue size. As elements are added to a priority queue, its capacity grows automatically. The details of the growth policy are not specified.

This class and its iterator implement all of the optional methods of the Collection and Iterator interfaces. The Iterator provided in method iterator() is not guaranteed to traverse the elements of the priority queue in any particular order. If you need ordered traversal, consider using Arrays::sort( pq.toArray() ).

Note that this implementation is not synchronized. Multiple threads should not access a PriorityQueue instance concurrently if any of the threads modifies the queue. Instead, use the thread-safe PriorityBlockingQueue class.

Implementation note: this implementation provides O(log(n)) time for the enqueing and dequeing methods (offer, poll, remove() and add); linear time for the remove(Object) and contains(Object) methods; and constant time for the retrieval methods (peek, element, and size).

Since: 1.0

Constructor & Destructor Documentation

template<typename E>

decaf::util::PriorityQueue< E >::PriorityQueue ( )

inline

Creates a Priority Queue with the default initial capacity.

References decaf::util::PriorityQueueBase::DEFAULT_CAPACITY.

template<typename E>

decaf::util::PriorityQueue< E >::PriorityQueue ( int initialCapacity )

inline

Creates a Priority Queue with the capacity value supplied.

Parameters

initialCapacity The initial number of elements allocated to this PriorityQueue.

template<typename E>

decaf::util::PriorityQueue< E >::PriorityQueue	(	int	initialCapacity,
		Comparator< E > *	comparator
	)

inline

Creates a Priority Queue with the default initial capacity.

This new PriorityQueue takes ownership of the passed Comparator instance and uses that to determine the ordering of the elements in the Queue.

Parameters

initialCapacity	The initial number of elements allocated to this PriorityQueue.
comparator	The Comparator instance to use in sorting the elements in the Queue.

Exceptions

NullPointerException if the passed Comparator is NULL.

References NULL.

template<typename E>

decaf::util::PriorityQueue< E >::PriorityQueue ( const Collection< E > & source )

inline

Creates a PriorityQueue containing the elements in the specified Collection.

Parameters

source the Collection whose elements are to be placed into this priority queue

template<typename E>

decaf::util::PriorityQueue< E >::PriorityQueue ( const PriorityQueue< E > & source )

inline

Creates a PriorityQueue containing the elements in the specified priority queue.

This priority queue will be ordered according to the same ordering as the given priority queue.

Parameters

source the priority queue whose elements are to be placed into this priority queue

template<typename E>

virtual decaf::util::PriorityQueue< E >::~PriorityQueue ( )

inlinevirtual

Member Function Documentation

template<typename E>

virtual bool decaf::util::PriorityQueue< E >::add ( const E & value )

inlinevirtual

References DECAF_CATCH_EXCEPTION_CONVERT, DECAF_CATCH_RETHROW, DECAF_CATCHALL_THROW, and decaf::util::PriorityQueue< E >::offer().

template<typename E>

virtual void decaf::util::PriorityQueue< E >::clear ( )

inlinevirtual

References decaf::util::PriorityQueueBase::DEFAULT_CAPACITY.

template<typename E>

decaf::lang::Pointer< Comparator<E> > decaf::util::PriorityQueue< E >::comparator ( ) const

inline

obtains a Copy of the Pointer instance that this PriorityQueue is using to compare the elements in the queue with.

The returned value is a copy, the caller cannot change the value if the internal Pointer value.

Returns: a copy of the Comparator Pointer being used by this Queue.

template<typename E>

virtual decaf::util::Iterator<E>* decaf::util::PriorityQueue< E >::iterator ( )

inlinevirtual

References decaf::util::PriorityQueue< E >::PriorityQueueIterator.

template<typename E>

virtual decaf::util::Iterator<E>* decaf::util::PriorityQueue< E >::iterator ( ) const

inlinevirtual

template<typename E>

virtual bool decaf::util::PriorityQueue< E >::offer ( const E & value )

inlinevirtual

Referenced by decaf::util::PriorityQueue< E >::add().

template<typename E>

PriorityQueue<E>& decaf::util::PriorityQueue< E >::operator= ( const Collection< E > & source )

inline

Assignment operator, assign another Collection to this one.

Parameters

source The Collection to copy to this one.

template<typename E>

PriorityQueue<E>& decaf::util::PriorityQueue< E >::operator= ( const PriorityQueue< E > & source )

inline

Assignment operator, assign another PriorityQueue to this one.

Parameters

source The PriorityQueue to copy to this one.

template<typename E>

virtual bool decaf::util::PriorityQueue< E >::peek ( E & result ) const

inlinevirtual

References decaf::util::AbstractCollection< E >::isEmpty().

template<typename E>

virtual bool decaf::util::PriorityQueue< E >::poll ( E & result )

inlinevirtual

References decaf::util::AbstractCollection< E >::isEmpty().

template<typename E>

virtual E decaf::util::PriorityQueue< E >::remove ( )

inlinevirtual

References decaf::util::AbstractCollection< E >::isEmpty().

template<typename E>

virtual bool decaf::util::PriorityQueue< E >::remove ( const E & value )

inlinevirtual

template<typename E>

virtual int decaf::util::PriorityQueue< E >::size ( ) const

inlinevirtual

Friends And Related Function Documentation

template<typename E>

friend class PriorityQueueIterator

friend

Referenced by decaf::util::PriorityQueue< E >::iterator().

The documentation for this class was generated from the following file:

src/main/decaf/util/PriorityQueue.h

Data Structures

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

template<typename E> class decaf::util::PriorityQueue< E >

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

template<typename E>
class decaf::util::PriorityQueue< E >