This class implements the Set interface, backed by a hash table (actually a HashMap instance). More...

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

Inheritance diagram for decaf::util::HashSet< E, HASHCODE >:

Public Member Functions

HashSet ()

Constructs a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75).

HashSet (int capacity)

Constructs a new, empty set; the backing HashMap instance has the specified initial capacity and default load factor (0.75).

HashSet (int capacity, float loadFactor)

Constructs a new instance of HashSet with the specified capacity and load factor.

HashSet (const Collection< E > &collection)

Constructs a new set containing the elements in the specified collection.

HashSet (const HashSet< E > &collection)

Constructs a new set containing the elements in the specified HashSet.

virtual ~HashSet ()

HashSet< E > & operator= (const Collection< E > &collection)

virtual bool add (const E &value)

Adds the specified element to this set if it is not already present.

virtual void clear ()

Removes all elements from this HashSet, leaving it empty.

virtual bool contains (const E &value) const

Searches this HashSet for the specified object.

virtual bool isEmpty () const

Returns true if this HashSet has no elements, false otherwise.

virtual Iterator< E > * iterator ()

Returns an Iterator on the elements of this HashSet.

virtual Iterator< E > * iterator () const

virtual bool remove (const E &value)

Removes the specified element from this set if it is present.

virtual int size () const

Returns the number of elements in this HashSet.

virtual std::string toString () const

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

AbstractSet ()

virtual ~AbstractSet ()

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.

This implementation iterates over this collection, checking each element returned by the iterator in turn to see if it's contained in the specified collection. If it's so contained, it's removed from this collection with the iterator's remove method.Note that this implementation will throw an UnsupportedOperationException if the iterator returned by the iterator method does not implement the remove method and this collection contains one or more elements in common with the specified collection.

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

virtual ~Set ()

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

virtual ~Collection ()

virtual void copy (const Collection< E > &collection)=0

Renders this Collection as a Copy of the given Collection.

virtual bool add (const E &value)=0

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

virtual bool addAll (const Collection< E > &collection)=0

Adds all of the elements in the specified collection to this collection.

virtual void clear ()=0

Removes all of the elements from this collection (optional operation).

virtual bool contains (const E &value) const =0

Returns true if this collection contains the specified element.

virtual bool containsAll (const Collection< E > &collection) const =0

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

virtual bool equals (const Collection< E > &value) const =0

Compares the passed collection to this one, if they contain the same elements, i.e.

virtual bool isEmpty () const =0

virtual bool remove (const E &value)=0

Removes a single instance of the specified element from the collection.

virtual bool removeAll (const Collection< E > &collection)=0

Removes all this collection's elements that are also contained in the specified collection (optional operation).

virtual bool retainAll (const Collection< E > &collection)=0

Retains only the elements in this collection that are contained in the specified collection (optional operation).

virtual int size () const =0

Returns the number of elements in this collection.

virtual std::vector< E > toArray () const =0

Returns an array containing all of the 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 ()

virtual void lock ()=0

Locks the object.

virtual bool tryLock ()=0

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

virtual void unlock ()=0

Unlocks the object.

virtual void wait ()=0

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

virtual void wait (long long millisecs)=0

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

virtual void wait (long long millisecs, int nanos)=0

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

virtual void notify ()=0

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

virtual void notifyAll ()=0

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

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

AbstractCollection ()

AbstractCollection (const AbstractCollection &other)

Copy Constructor, copy element from the source collection to this collection after clearing any element stored in this collection.

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 void clear ()

Removes all of the elements from this collection (optional operation).

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 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.

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.

Protected Member Functions
	HashSet (HashMap< E, Set< E > , HASHCODE > backingMap)
	Protected constructor for use by subclasses that wish to use an alternate type of backing Map.

Protected Attributes
HashMap< E, Set< E > , HASHCODE >	backingMap

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

Detailed Description

template<typename E, typename HASHCODE = HashCode<E>>
class decaf::util::HashSet< E, HASHCODE >

This class implements the Set interface, backed by a hash table (actually a HashMap instance).

It makes no guarantees as to the iteration order of the set; in particular, it does not guarantee that the order will remain constant over time.

This class offers constant time performance for the basic operations (add, remove, contains and size), assuming the hash function disperses the elements properly among the buckets. Iterating over this set requires time proportional to the sum of the HashSet instance's size (the number of elements) plus the "capacity" of the backing HashMap instance (the number of buckets). Thus, it's very important not to set the initial capacity too high (or the load factor too low) if iteration performance is important.

Note that this implementation is not synchronized. If multiple threads access a hash set concurrently, and at least one of the threads modifies the set, it must be synchronized externally. This is typically accomplished by synchronizing on some object that naturally encapsulates the set. If no such object exists, the set should be "wrapped" using the Collections::synchronizedSet method. This is best done at creation time, to prevent accidental unsynchronized access to the set:

Set<E>* s = Collections::synchronizedSet(new HashSet<E>(...));

The iterators returned by this class's iterator method are fail-fast: if the set is modified at any time after the iterator is created, in any way except through the iterator's own remove method, the Iterator throws a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

Since: 1.0

Constructor & Destructor Documentation

◆ HashSet() [1/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet ( )

inline

Constructs a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75).

◆ HashSet() [2/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet ( int capacity )

inline

Constructs a new, empty set; the backing HashMap instance has the specified initial capacity and default load factor (0.75).

Parameters

capacity The initial capacity of this HashSet.

◆ HashSet() [3/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet	(	int	capacity,
		float	loadFactor
	)

inline

Constructs a new instance of HashSet with the specified capacity and load factor.

Parameters

capacity	The initial capacity for this HashSet.
loadFactor	The initial load factor for this HashSet.

◆ HashSet() [4/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet ( const Collection< E > & collection )

inline

Constructs a new set containing the elements in the specified collection.

The HashMap is created with default load factor (0.75) and an initial capacity sufficient to contain the elements in the specified collection.

Parameters

collection The collection of elements to add to this HashSet.

References decaf::util::HashSet< E, HASHCODE >::add(), decaf::lang::Iterable< E >::iterator(), and decaf::util::Collection< E >::size().

◆ HashSet() [5/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet ( const HashSet< E > & collection )

inline

Constructs a new set containing the elements in the specified HashSet.

The HashMap is created with default load factor (0.75) and an initial capacity sufficient to contain the elements in the specified collection.

Parameters

collection The collection of elements to add to this HashSet.

References decaf::util::HashSet< E, HASHCODE >::add(), decaf::util::HashSet< E, HASHCODE >::iterator(), and decaf::util::HashSet< E, HASHCODE >::size().

◆ ~HashSet()

template<typename E , typename HASHCODE = HashCode<E>>

virtual decaf::util::HashSet< E, HASHCODE >::~HashSet ( )

inlinevirtual

References decaf::util::HashSet< E, HASHCODE >::backingMap, and DECAF_CATCHALL_NOTHROW.

◆ HashSet() [6/6]

template<typename E , typename HASHCODE = HashCode<E>>

decaf::util::HashSet< E, HASHCODE >::HashSet ( HashMap< E, Set< E > *, HASHCODE > * backingMap )

inlineprotected

Protected constructor for use by subclasses that wish to use an alternate type of backing Map.

Parameters

backingMap The instance of the Map type used to back this HashSet.

Member Function Documentation

◆ add()

template<typename E , typename HASHCODE = HashCode<E>>

virtual bool decaf::util::HashSet< E, HASHCODE >::add ( const E & value )

inlinevirtual

Adds the specified element to this set if it is not already present.

More formally, adds the specified element e to this set if this set contains no element e2 such that (e == e2). If this set already contains the element, the call leaves the set unchanged and returns false.

Parameters

value The object to add.

Returns: true when this HashSet did not already contain the object,false otherwise.

Implements decaf::util::Collection< E >.

References decaf::util::HashMap< K, V, HASHCODE >::put().

Referenced by decaf::util::HashSet< E, HASHCODE >::HashSet(), and decaf::util::LinkedHashSet< E, HASHCODE >::LinkedHashSet().

◆ clear()

template<typename E , typename HASHCODE = HashCode<E>>

virtual void decaf::util::HashSet< E, HASHCODE >::clear ( )

inlinevirtual

Removes all elements from this HashSet, leaving it empty.

See also: isEmpty; size

Reimplemented from decaf::util::AbstractCollection< E >.

References decaf::util::HashMap< K, V, HASHCODE >::clear().

Referenced by decaf::util::HashSet< E, HASHCODE >::operator=().

◆ contains()

template<typename E , typename HASHCODE = HashCode<E>>

virtual bool decaf::util::HashSet< E, HASHCODE >::contains ( const E & value ) const

inlinevirtual

Searches this HashSet for the specified object.

Parameters

value the object to search for.

Returns: true if object is an element of this HashSet, false otherwise.

Reimplemented from decaf::util::AbstractCollection< E >.

References decaf::util::HashMap< K, V, HASHCODE >::containsKey().

◆ isEmpty()

template<typename E , typename HASHCODE = HashCode<E>>

virtual bool decaf::util::HashSet< E, HASHCODE >::isEmpty ( ) const

inlinevirtual

Returns true if this HashSet has no elements, false otherwise.

Returns: true if this HashSet has no elements, false otherwise.

See also: size

Reimplemented from decaf::util::AbstractCollection< E >.

References decaf::util::HashMap< K, V, HASHCODE >::isEmpty().

◆ iterator() [1/2]

template<typename E , typename HASHCODE = HashCode<E>>

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

inlinevirtual

Returns an Iterator on the elements of this HashSet.

Returns: an Iterator on the elements of this HashSet.

See also: Iterator

Implements decaf::lang::Iterable< E >.

References decaf::lang::Iterable< E >::iterator(), and decaf::util::HashMap< K, V, HASHCODE >::keySet().

Referenced by decaf::util::HashSet< E, HASHCODE >::HashSet().

◆ iterator() [2/2]

template<typename E , typename HASHCODE = HashCode<E>>

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

inlinevirtual

Implements decaf::lang::Iterable< E >.

References decaf::lang::Iterable< E >::iterator(), and decaf::util::HashMap< K, V, HASHCODE >::keySet().

◆ operator=()

template<typename E , typename HASHCODE = HashCode<E>>

HashSet< E > & decaf::util::HashSet< E, HASHCODE >::operator= ( const Collection< E > & collection )

inline

References decaf::util::AbstractCollection< E >::addAll(), and decaf::util::HashSet< E, HASHCODE >::clear().

◆ remove()

template<typename E , typename HASHCODE = HashCode<E>>

virtual bool decaf::util::HashSet< E, HASHCODE >::remove ( const E & value )

inlinevirtual

Removes the specified element from this set if it is present.

More formally, removes an element e such that (e == value), if this set contains such an element. Returns true if this set contained the element (or equivalently, if this set changed as a result of the call). (This set will not contain the element once the call returns.)

Parameters

value The value to remove from this set.