CuData Class Reference

container for data exchange for the cumbia library and its clients More...

#include <cudata.h>

Public Member Functions
virtual	~CuData ()
	the class destructor More...
	CuData ()
	constructor of an empty CuData More...
	CuData (const CuVariant &v)
	constructor of a CuData initialised with one value (key: emtpy string) More...
	CuData (const std::string &key, const CuVariant &v)
	constructor initialising a CuData with one key-value pair More...
	CuData (const CuData &other)
	the copy constructor More...
	CuData (CuData &&other)
	c++11 move constructor More...
virtual CuData &	operator= (const CuData &other)
	assignment operator, copies data from another source More...
virtual CuData &	operator= (CuData &&other)
	move assignment operator, moves contents from another source More...
CuData &	set (const std::string &key, const CuVariant &value)
CuData &	merge (const CuData &other)
CuData &	merge (const CuData &&other)
CuData	clone () const
	clone this data, without sharing More...
CuData &	remove (const std::string &key)
CuData	remove (const std::string &key) const
CuData &	remove (const std::vector< std::string > &keys)
CuData	remove (const std::vector< std::string > &keys) const
size_t	size () const
	returns the number of key-value pairs stored More...
CuVariant	value () const
	return the value associated to the empty key More...
CuVariant	value (const std::string &key) const
	return a copy of the value associated with the given key, or an invalid and null CuVariant More...
void	add (const std::string &key, const CuVariant &value)
	insert the key/value into the bundle More...
bool	containsKey (const std::string &key) const
	returns true if the bundle contains the given key More...
bool	has (const std::string &key, const std::string &value) const
	returns true if the specified key has the given string value More...
CuVariant &	operator[] (const std::string &key)
	array subscript write operator; pushes a new key-value pair into the bundle More...
const CuVariant &	operator[] (const std::string &key) const
	array subscript read operator: get a reference to a value given the key More...
virtual bool	operator== (const CuData &other) const
	equality relational operator. Returns true if this CuData equals another More...
virtual bool	operator!= (const CuData &other) const
	inequality relational operator. Returns true if the equality operator CuData::operator == returns false More...
bool	isEmpty () const
	returns true if there are no key-value pairs stored More...
void	print () const
	prints the representation of the object provided by toString using printf More...
std::string	toString () const
	write a representation of this object into a std::string More...
void	putTimestamp ()
	put date and time information into this object More...
std::vector< std::string >	keys () const
std::string	s (const std::string &key) const
double	d (const std::string &key) const
int	i (const std::string &key) const
unsigned int	u (const std::string &key) const
bool	b (const std::string &key) const
double	D (const std::string &key) const
int	I (const std::string &key) const
unsigned int	U (const std::string &key) const
bool	B (const std::string &key) const
std::vector< double >	DV (const std::string &key) const
std::vector< int >	IV (const std::string &key) const
std::vector< long long >	LLV (const std::string &key) const
std::vector< unsigned int >	UV (const std::string &key) const
std::vector< unsigned long int >	ULV (const std::string &key) const
std::vector< unsigned long long int >	ULLV (const std::string &key) const
std::vector< bool >	BV (const std::string &key) const

Detailed Description

container for data exchange for the cumbia library and its clients

CuData is a bundle that stores key-value pairs. The key is a std::string, the value is of type CuVariant. A copy of the value associated to a key can be obtained with CuData::value(const std::string& key). A value can be accessed with the [] operator. [] operators are defined in the const and non const flavours. The non const version allows to insert new CuVariant values with a string key within the square brackets.

The parameterless CuData::value version returns the value associated to an empty key, if there is one, created for example with the CuData::CuData(const CuVariant &v) constructor.

The number of key-value pairs stored by CuData can be queried with CuData::size. CuData::isEmpty returns true if the CuData has no key/value pair. CuData::containsKey tells whether a given key is or not in the bundle. CuData::add can be used to add a key-value pair. The result is equivalent to using the [] operator.

Two CuData can be compared with the == and != operators. The == operator returns true if the two bundles contain the same keys and each of their values correspond. The operator != returns the opposite value of the operator ==

The CuData::toString method returns a std::string representation of its contents. The contents of a CuData can be printed on the console by means of CuData::print

The CuVariant variant type

Please read the CuVariant documentation to understand the cumbia CuVariant type.

Implicit sharing

Since

1.4.0

Data is implicitly shared, enabling copy on write. Atomic reference counters make the class reentrant, meaning that methods can be called from multiple threads, but only if each invocation uses its own data. Atomic reference counting is used to ensure the integrity of the shared data. Since cumbia 1.4.0, CuData uses implicit sharing as well.

Constructor & Destructor Documentation

~CuData()

CuData::~CuData ( )

virtual

the class destructor

CuData class destructor

CuData() [1/5]

CuData::CuData

(

)

constructor of an empty CuData

builds a CuData with no key/value

Referenced by remove().

CuData() [2/5]

CuData::CuData

(

const CuVariant &

v

)

constructor of a CuData initialised with one value (key: emtpy string)

Parameters

v	a CuVariant used to initialise a key/value pair where the key is an empty string.

The parameter-less of CuData::value can be used to get the value associated to an empty key

CuData() [3/5]

CuData::CuData	(	const std::string &	key,
		const CuVariant &	v
	)

constructor initialising a CuData with one key-value pair

Parameters

key	a string used as a key
v	the value, as CuVariant

The new CuData will be initialised with a key/v pair

CuData() [4/5]

CuData::CuData

(

const CuData &

other

)

the copy constructor

Parameters

other

another CuData used as the source of the copy

copies all the contents from the other CuData into the new object

CuData() [5/5]

CuData::CuData

(

CuData &&

other

)

c++11 move constructor

Parameters

other

another CuData used as the source of the move operation

Contents of other are moved into this CuData

Member Function Documentation

add()

void CuData::add	(	const std::string &	key,
		const CuVariant &	value
	)

insert the key/value into the bundle

Parameters

key	the new key, as a std::string
value	the new value bound to key

Note

The effect is exactly the same as using the operator [] (const std::string& key)

References value().

Referenced by putTimestamp().

b()

bool CuData::b

(

const std::string &

key

)

const

References containsKey(), CuVariant::d(), and operator[]().

Referenced by B().

B()

bool CuData::B

(

const std::string &

key

)

const

References b(), containsKey(), operator[](), and CuVariant::to().

Referenced by CuDataSerializer::serialize().

BV()

std::vector< bool > CuData::BV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

clone()

CuData CuData::clone

(

)

const

clone this data, without sharing

Returns

a clone of this data, bypassing the copy-on-write share

References d().

containsKey()

bool CuData::containsKey

(

const std::string &

key

)

const

returns true if the bundle contains the given key

Parameters

key	the key to be searched, std::string

Returns

true if the bundle contains the given key, false otherwise

Referenced by b(), B(), BV(), D(), DV(), I(), IV(), LLV(), CuDataSerializer::serialize(), U(), ULLV(), ULV(), and UV().

d()

double CuData::d

(

const std::string &

key

)

const

References CuVariant::d(), and operator[]().

Referenced by clone().

D()

double CuData::D

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::to().

DV()

std::vector< double > CuData::DV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

has()

bool CuData::has	(	const std::string &	key,
		const std::string &	value
	)		const

returns true if the specified key has the given string value

This method is a shortcut to test if to a given key is associated a string with the given value.

Parameters

key	the key
value	the value as string

Returns

true if data[key].toString() == value false otherwise

References value().

i()

int CuData::i

(

const std::string &

key

)

const

References CuVariant::i(), and operator[]().

I()

int CuData::I

(

const std::string &

key

)

const

References containsKey(), i, operator[](), and CuVariant::to().

isEmpty()

bool CuData::isEmpty

(

)

const

returns true if there are no key-value pairs stored

Returns

true there is no data stored, false if there is at least one key-value pair

See also

size

IV()

std::vector< int > CuData::IV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

keys()

std::vector< std::string > CuData::keys

(

)

const

Referenced by merge(), and remove().

LLV()

std::vector< long long > CuData::LLV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

merge() [1/2]

CuData & CuData::merge

(

const CuData &&

other

)

merge() [2/2]

CuData & CuData::merge

(

const CuData &

other

)

References keys(), and value().

operator!=()

bool CuData::operator!= ( const CuData &  other ) const

virtual

inequality relational operator. Returns true if the equality operator CuData::operator == returns false

Returns

true if the equality operator CuData::operator== returns false, false otherwise

References operator==().

operator=() [1/2]

CuData & CuData::operator= ( const CuData &  other )

virtual

assignment operator, copies data from another source

Parameters

other

another CuData which values will be copied into this

operator=() [2/2]

CuData & CuData::operator= ( CuData &&  other )

virtual

move assignment operator, moves contents from another source

Parameters

other

another CuData which values will be moved into this

operator==()

bool CuData::operator== ( const CuData &  other ) const

virtual

equality relational operator. Returns true if this CuData equals another

Parameters

other

another CuData (const reference)

Returns

true if other contains the same keys as this and every key of other has the same value as the corresponding key in this

the inequality operator is also defined

Referenced by operator!=().

operator[]() [1/2]

CuVariant & CuData::operator[]

(

const std::string &

key

)

array subscript write operator; pushes a new key-value pair into the bundle

Use the insert operator to add a new key/value pair to the bundle

Example

CuData at("src", source.getName()); // string
at["device"] = source.getDeviceName(); // string
at["activity"] = "E"; // string
at["period"] = source.period(); // integer
at["err"] = false; // bool

Referenced by b(), B(), BV(), d(), D(), DV(), i(), I(), IV(), LLV(), s(), u(), U(), ULLV(), ULV(), and UV().

operator[]() [2/2]

const CuVariant & CuData::operator[]

(

const std::string &

key

)

const

array subscript read operator: get a reference to a value given the key

Parameters

key	the key to search for

Returns

reference to the value for the given key or a reference to an empty CuVariant if the key is not found.

Note

An empty CuVariant::isValid method returns false and CuVariant::isNull returns true

print()

void CuData::print

(

)

const

prints the representation of the object provided by toString using printf

Prints a string representation of the contents of this object on the console, using printf.

See also

toString

References toString().

putTimestamp()

void CuData::putTimestamp

(

)

put date and time information into this object

writes the following keys into this object, taking the system clock time from the gettimeofday call.

• "timestamp_ms" timestamp in milliseconds, convert with CuVariant::toLongInt
• "timestamp_us" timestamp in microseconds, convert with CuVariant::toLongInt

References add().

remove() [1/4]

CuData & CuData::remove

(

const std::string &

key

)

remove() [2/4]

CuData CuData::remove

(

const std::string &

key

)

const

References CuData().

remove() [3/4]

CuData & CuData::remove

(

const std::vector< std::string > &

keys

)

References keys().

remove() [4/4]

CuData CuData::remove

(

const std::vector< std::string > &

keys

)

const

References CuData(), and keys().

s()

std::string CuData::s

(

const std::string &

key

)

const

References operator[](), and CuVariant::s().

Referenced by CuDataSerializer::deserialize(), and CuDataSerializer::serialize().

set()

CuData & CuData::set	(	const std::string &	key,
		const CuVariant &	value
	)

References value().

Referenced by CuDataSerializer::deserialize().

size()

size_t CuData::size

(

)

const

returns the number of key-value pairs stored

Returns

the number of key-value pairs stored within this object

See also

isEmpty

toString()

std::string CuData::toString

(

)

const

write a representation of this object into a std::string

Returns

a std::string with a representation of this object.

All keys are printed with their values (CuVariant is always converted to string with CuVariant::toString). At last, the number of key/values stored and the flag returned by CuData::isEmpty are printed.

See also

print

References i.

Referenced by print().

u()

unsigned int CuData::u

(

const std::string &

key

)

const

References operator[](), and CuVariant::u().

U()

unsigned int CuData::U

(

const std::string &

key

)

const

References containsKey(), i, operator[](), and CuVariant::to().

ULLV()

std::vector< unsigned long long > CuData::ULLV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

ULV()

std::vector< unsigned long > CuData::ULV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

UV()

std::vector< unsigned int > CuData::UV

(

const std::string &

key

)

const

References containsKey(), operator[](), and CuVariant::toVector().

value() [1/2]

CuVariant CuData::value

(

)

const

return the value associated to the empty key

Returns

the value associated to an empty key, if there's one empty key with a value (for example, created with the CuData::CuData(const CuVariant &v) ) constructor, or an empty CuVariant

If there's no value associated to an empty key (i.e. an emtpy string, ""), an invalid and null CuVariant is returned. See CuVariant::isValid and CuVariant::isNull

Referenced by add(), has(), merge(), and set().

value() [2/2]

CuVariant CuData::value

(

const std::string &

key

)

const

return a copy of the value associated with the given key, or an invalid and null CuVariant

Returns

a copy of the value associated with the given key, or an invalid and null CuVariant. See CuVariant::isValid and CuVariant::isNull

See also CuData::operator [](const std::string &key) const

---

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

• cudata.h
• cudata.cpp