Implements a dictionary based on a hash table. More...

#include <jem/util/HashDictionary.h>

Inheritance diagram for jem::util::HashDictionary:

Public Types
typedef Dictionary	Super

typedef HashDictionary	Self

Public Member Functions
	HashDictionary ()
	Constructs an empty hash dictionary. More...

virtual Class *	getClass () const
	Returns the `Class` instance representing the runtime class of this object. More...

virtual void	readFrom (io::ObjectInput &in)

virtual void	writeTo (io::ObjectOutput &out) const

virtual Ref< Object >	clone () const

virtual Ref< DictionaryEnumerator >	getDictEnumerator () const
	Returns an enumerator over this dictionary. More...

virtual bool	find (Ref< Object > &value, const String &key) const
	Searches for an object associated with a specific key. More...

virtual void	insert (const String &key, const Ref< Object > &value)
	Inserts a key/value pair into this dictionary. More...

virtual void	erase (const String &key)
	Deletes a key/value pair from this dictionary. More...

virtual void	clear ()
	Deletes all objects from this collection. More...

virtual void	reserve (int n)
	Expands the hash table for additional key/value pairs. More...

virtual void	trimToSize ()
	De-allocates non-used memory. More...

virtual int	capacity () const
	Returns the capacity of this dictionary. More...

virtual int	size () const
	Returns the number of objects in this collection. More...

Public Member Functions inherited from jem::util::Dictionary
Ref< DictionaryEnumerator >	enumerate () const
	Returns an enumerator over this dictionary. More...

virtual Ref< Enumerator >	getEnumerator () const
	Returns an enumerator over this dictionary. More...

virtual bool	contains (const String &key) const
	Checks whether this dictionary contains a specific key. More...

virtual Ref< Object >	get (const String &key) const
	Returns the object associated with a specific key. More...

virtual bool	add (const Ref< Object > &obj)
	Adds a key/value pair to this dictionary. More...

Public Member Functions inherited from jem::util::ObjectCollection
Ref< Enumerator >	enumerate () const
	Returns an enumerator over this collection. More...

Public Member Functions inherited from jem::Object
virtual String	toString () const
	Returns a short textual description of this object. More...

virtual long	hashValue () const
	Returns a hash value for this object. More...

virtual bool	equals (const Ref< Object > &obj) const
	Tests whether two objects are equal. More...

Ref< Object >	clone () const
	Returns a copy of this object. More...

Static Public Member Functions
static Class *	makeClass ()

static Class *	getType ()

Static Public Member Functions inherited from jem::util::Dictionary
static Class *	makeClass ()

static Class *	getType ()

Static Public Member Functions inherited from jem::util::ObjectCollection
static Class *	makeClass ()

static Class *	getType ()

Static Public Member Functions inherited from jem::Object
static Class *	getType ()
	Returns the `Class` instance representing the `Object` class. More...

Protected Member Functions
virtual	~HashDictionary ()

Protected Member Functions inherited from jem::util::Dictionary
virtual	~Dictionary ()

void	readFrom_ (io::ObjectInput &in)
	Reads the contents of this dictionary from an object input stream. More...

void	writeTo_ (io::ObjectOutput &out) const
	Writes the contents of this dictionary to an object output stream. More...

void	clone_ (const Dictionary &rhs)
	Makes a deep copy of another dictionary. More...

Protected Member Functions inherited from jem::util::ObjectCollection
virtual	~ObjectCollection ()

void	clone_ (const ObjectCollection &rhs)
	Makes a deep copy of another collection. More...

void	readFrom_ (io::ObjectInput &in)
	Reads the contents of this collection from an object input stream. More...

void	writeTo_ (io::ObjectOutput &out) const
	Writes the contents of this collection to an object output stream. More...

Protected Member Functions inherited from jem::Collectable
	Collectable ()
	Creates an empty `Collectable`. More...

	~Collectable ()
	Frees resources. More...

Protected Member Functions inherited from jem::util::Enumerable
virtual	~Enumerable ()

Protected Member Functions inherited from jem::Interface
virtual	~Interface ()
	Empty destructor. More...

Protected Member Functions inherited from jem::Clonable
virtual	~Clonable ()

virtual void	emitVTable_ ()

Protected Member Functions inherited from jem::io::Serializable
virtual	~Serializable ()

virtual void	emitVtableFunc_ ()

Detailed Description

The HashDictionary class uses a hash table to implement the interface defined by the Dictionary class. It has two important properties. First, the time it takes to insert or to find a key/value pair does not – on average – depend on the total number key/value pairs. Second, the order of a HashDictionary is not defined. That is, an enumerator returned by a HashDictionary iterates over the key/value pairs in a arbitrary order.

Reading from a HashDictionary is thread safe. To be precise, the following functions may be called by multiple threads concurrently: enumerate(), getDictEnumerator(), find() and size(). All other functions are not thread safe.

Examples:: meshgen.cpp.

Member Typedef Documentation

typedef Dictionary jem::util::HashDictionary::Super

typedef HashDictionary jem::util::HashDictionary::Self

Constructor & Destructor Documentation

jem::util::HashDictionary::HashDictionary ( )

Constructs an empty HashDictionary.

Postcondition: size() == 0

virtual jem::util::HashDictionary::~HashDictionary ( )

protectedvirtual

Member Function Documentation

static Class* jem::util::HashDictionary::makeClass ( )

static

static Class* jem::util::HashDictionary::getType ( )

static

virtual Class* jem::util::HashDictionary::getClass ( ) const

virtual

Returns a pointer to the Class instance representing the runtime class of this object. If T denotes the runtime class of this object, then this function is equivalent with T::getType(). The pointer is valid during the entire lifetime of the program.

Returns: A pointer to the Class instance representing the runtime class of this object.

Reimplemented from jem::util::Dictionary.

virtual void jem::util::HashDictionary::readFrom ( io::ObjectInput & in )

virtual

Implements jem::io::Serializable.

virtual void jem::util::HashDictionary::writeTo ( io::ObjectOutput & out ) const

virtual

Implements jem::io::Serializable.

virtual Ref<Object> jem::util::HashDictionary::clone ( ) const

virtual

Implements jem::Clonable.

virtual Ref<DictionaryEnumerator> jem::util::HashDictionary::getDictEnumerator ( ) const

virtual

Returns a DictionaryEnumerator that can be used to iterate over all key/value pairs in this dictionary. The enumerator points to the first key/value pair, or to the special end object if this dictionary is empty.

This dictionary may not be structurally modified as long as one or more enumerators are pointing to it.

Returns: A DictionaryEnumerator over this dictionary.

Implements jem::util::Dictionary.

virtual bool jem::util::HashDictionary::find	(	Ref< Object > &	value,
		const String &	key
	)		const

virtual

Searches for the object that is associated with the key key. If the object is found, then its address is stored in the output parameter value and true is returned. Otherwise, false is returned and the output parameter value is not modified.

This function may not be called if an enumerator points to this dictionary.

Parameters

value	- a reference in which the address of the object to be found is stored.
key	- the key associated with the object to be found.

Returns: true if this dictionary contains the key key, and false otherwise.

Implements jem::util::Dictionary.

virtual void jem::util::HashDictionary::insert	(	const String &	key,
		const Ref< Object > &	value
	)

virtual

Inserts a key/value pair in this dictionary. If this dictionary already contains the key key, then its associated value is replaced by the parameter value.

This function may not be called if an enumerator points to this dictionary.

Parameters

key	- a key string.
value	- the object associated with the key key.

Implements jem::util::Dictionary.

virtual void jem::util::HashDictionary::erase ( const String & key )

virtual

Deletes the key key and its associated value from this dictionary. If this dictionary does not contain the specified key, then this function has no effect.

This function may not be called if an enumerator points to this dictionary.

Parameters

key	- the key to be deleted.

Implements jem::util::Dictionary.

virtual void jem::util::HashDictionary::clear ( )

virtual

Deletes all objects from this collection.

This function may not be called if an enumerator points to this collection.

Postcondition: this->size() == 0

Implements jem::util::ObjectCollection.

virtual void jem::util::HashDictionary::reserve ( int n )

virtual

Expands the internal hash table and pre-allocates memory for additional key/value pairs. The input arguments n specifies the total number of key/value pairs that will be stored in this dictionary. This function speeds up subsequent calls to the member functions insert() and add().

Note that the internal hash table of this dictionary is resized automatically when needed, even if this function is not called. By calling this function, however, you can reduce the number of times that the hash table has to be resized.

This function may not be called if an enumerator points to this collection.

Reimplemented from jem::util::ObjectCollection.

virtual void jem::util::HashDictionary::trimToSize ( )

virtual

De-allocates non-used memory and shrinks the internal hash table if possible.

This function may not be called if an enumerator points to this collection.

Reimplemented from jem::util::ObjectCollection.

virtual int jem::util::HashDictionary::capacity ( ) const

virtual

Returns the number of key/value pairs that this dictionary can contain without having to expand its internal data structures.

Reimplemented from jem::util::ObjectCollection.

virtual int jem::util::HashDictionary::size ( ) const