Hashtable Class Reference

Inheritance diagram for Hashtable:

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Collaboration diagram for Hashtable:

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Public Member Functions
	Hashtable (void)
	~Hashtable (void)
	Hashtable (const Hashtable &toCopy)
Hashtable &	operator= (const Hashtable &toCopy)
bool	operator== (const Hashtable &toCompare) const
bool	operator!= (const Hashtable &toCompare) const
const Object &	operator[] (unsigned int index) const
Object &	operator[] (unsigned int index)
void	put (const Hashtable &src)
template<typename FKeyType , typename FValueType >
void	put (const FKeyType &key, const FValueType &val)
template<typename FKeyType >
void	put (const FKeyType &key)
template<typename FKeyType , typename FValueType >
void	put (const FKeyType &key, const FValueType pVal, typename Common::Helpers::ArrayLengthType< FValueType >::type size)
template<typename FKeyType , typename FValueType >
void	put (const FKeyType &key, const FValueType pVal, const short *sizes)
template<typename FKeyType >
const Object *	getValue (const FKeyType &key) const
unsigned int	getSize (void) const
const JVector< Object > &	getKeys (void) const
template<typename FKeyType >
void	remove (const FKeyType &key)
template<typename FKeyType >
bool	contains (const FKeyType &key) const
void	removeAllElements (void)
JString &	toString (JString &retStr, bool withTypes=false) const
Public Member Functions inherited from Base
virtual	~Base (void)
Public Member Functions inherited from ToString
virtual	~ToString (void)
virtual JString	typeToString (void) const
JString	toString (bool withTypes=false) const

Additional Inherited Members
Static Public Member Functions inherited from Base
static void	setListener (const BaseListener *baseListener)
static int	getDebugOutputLevel (void)
static bool	setDebugOutputLevel (int debugLevel)
static const LogFormatOptions &	getLogFormatOptions (void)
static void	setLogFormatOptions (const LogFormatOptions &options)

Detailed Description

The Hashtable class together with the Dictionary class template is one of the two main container classes for objects to be transmitted over Photon when using the C++ Client.

This class implements the well-known concept of a container structure storing an arbitrary number of key/value-pairs.

In contrast to a Dictionary, the types of both the keys and also the values in a Hashtable can differ for every entry. This adds flexibility, but it also reduces type safety and means, that the type infos have to be stored twice (once for the key and once for the value) per entry in a Hashtable, while in a Dictionary it only has to be stored twice for the whole Dictionary, no matter how many entries are in there. Therefor with Dictionaries transferring the same amount of key-value pairs will cause less traffic than with Hashtables.

Please have a look at the Table of Datatypes for a list of types, that are supported as keys and as values.

Please refer to the documentation for put() and getValue() to see how to store and access data in a Hashtable.

See also

put(), getValue(), KeyObject, ValueObject, Dictionary

Constructor & Destructor Documentation

Hashtable() [1/2]

Hashtable

(

void

)

Constructor: Creates an empty instance.

~Hashtable()

~Hashtable

(

void

)

Destructor.

Hashtable() [2/2]

Hashtable

(

const Hashtable &

toCopy

)

Copy-Constructor: Creates a deep copy of the argument.

Parameters

toCopy

The object to copy.

Member Function Documentation

operator=()

Hashtable & operator=

(

const Hashtable &

toCopy

)

operator=. Makes a deep copy of its right operand into its left operand. This overwrites old data in the left operand.

operator==()

bool operator==

(

const Hashtable &

toCompare

)

const

operator==.

Returns

true, if both operands are equal, false otherwise.

Two instances are considered equal if they each hold the same number of entries and, for a given key, the corresponding values equal each other.

Two values are considered equal to each other, if instances of class Object, that are holding them as payloads, equal each other.

See also

Object::operator==()

operator!=()

bool operator!=

(

const Hashtable &

toCompare

)

const

operator!=.

Returns

false, if operator==() would return true, true otherwise.

operator[]() [1/2]

const Object & operator[]

(

unsigned int

index

)

const

operator[].

Accesses the value at the given index like in an array. This does not check for valid indexes and shows undefined behavior for invalid indexes

operator[]() [2/2]

Object & operator[]

(

unsigned int

index

)

operator[].

Accesses the value at the given index like in an array. This does not check for valid indexes and shows undefined behavior for invalid indexes

put() [1/5]

void put

(

const Hashtable &

src

)

Adds all pairs of a key and a corresponding value from the passed instance to the instance, on which it is called on. If a key is already existing, then its old value will be replaced with the new one.

Parameters

src	instance, from which to add the content

Returns

nothing.

put() [2/5]

void put	(	const FKeyType &	key,
		const FValueType &	val
	)

Adds a pair of a key and a corresponding value to the instance.

If the key is already existing, then it's old value will be replaced with the new one. Please have a look at the table of datatypes for a list of supported types for keys and values

Parameters

key	the key to add
val	the value to add

Returns

nothing.

put() [3/5]

void put

(

const FKeyType &

key

)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

This overload adds an empty object as value for the provided key.

put() [4/5]

void put	(	const FKeyType &	key,
		const FValueType	pVal,
		typename Common::Helpers::ArrayLengthType< FValueType >::type	size
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

This overload accepts singledimensional arrays and NULL-pointers passed for parameter pVal. NULL pointers are only legal input, if size is 0

Parameters

key	the key to add
pVal	the value array to add
size	the size of the value array

put() [5/5]

void put	(	const FKeyType &	key,
		const FValueType	pVal,
		const short *	sizes
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

This overload accepts multidimensional arrays and NULL-pointers passed for parameter pVal. The array that is passed for parameter pVal has to be a pointer of the correct abstraction level, meaning a normal pointer for a singledimensional array, a doublepointer for a twodimensional array, a triplepointer for a threedimensional array and so on. For pVal NULL pointers are only legal input, if sizes[0] is 0. For sizes NULL is no valid input.

Parameters

key	the key to add
pVal	the value array to add
sizes	the sizes for every dimension of the value array - the length of this array has to match the dimensions of pVal

getValue()

const Object * getValue

(

const FKeyType &

key

)

const

Returns the corresponding value for a specified key.

Parameters

key	Reference to the key to return the corresponding value for.

Returns

a pointer to the corresponding value if the Hashtable contains the specified key, NULL otherwise.

See also

put()

getSize()

unsigned int getSize

(

void

)

const

Returns

the number of key/value pairs stored in the Hashtable.

getKeys()

const JVector< Object > & getKeys

(

void

)

const

Returns

a JVector holding all keys contained in the Hashtable.

remove()

void remove

(

const FKeyType &

key

)

Deletes the specified key and the corresponding value, if found in the Hashtable.

Parameters

key	Pointer to the key of the key/value-pair to remove.

Returns

nothing.

See also

removeAllElements()

contains()

bool contains

(

const FKeyType &

key

)

const

Checks, whether the Hashtable contains a certain key.

Parameters

key	Pointer to the key to look up.

Returns

true if the specified key was found, false otherwise.

removeAllElements()

void removeAllElements

(

void

)

Clears the Hashtable, which means deleting all its content.

Returns

nothing.

See also

remove()

toString()

JString & toString ( JString &  retStr, bool  withTypes = false  ) const

virtual

Remarks

The cost of this function depends a lot on implementation details of the implementing subclasses, but for container classes this function can become quite expensive, if the instance contains huge amounts of data, as its cost for many container class implementations increases disproportionately high to the size of the payload.

Parameters

retStr	reference to a string, to store the return-value in; the information, which is generated by this function, will be attached at the end of any eventually existing previous content of the string
withTypes	set to true, to include type information in the generated string

Returns

a JString representation of the instance and its contents for debugging purposes.

Implements ToString.