File Storage Node class. More...

#include <opencv2/core/persistence.hpp>

Collaboration diagram for cv::FileNode:

Public Types
enum	{ NONE = 0, INT = 1, REAL = 2, FLOAT = REAL, STR = 3, STRING = STR, SEQ = 4, MAP = 5, TYPE_MASK = 7, FLOW = 8, UNIFORM = 8, EMPTY = 16, NAMED = 32 }
	type of the file storage node More...

Public Member Functions
	FileNode ()
	The constructors. More...

	FileNode (const FileStorage *fs, size_t blockIdx, size_t ofs)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

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

FileNodeIterator	begin () const
	returns iterator pointing to the first node element More...

bool	empty () const
	returns true if the node is empty More...

FileNodeIterator	end () const
	returns iterator pointing to the element following the last node element More...

bool	isInt () const
	returns true if the node is an integer More...

bool	isMap () const
	returns true if the node is a mapping More...

bool	isNamed () const
	returns true if the node has a name More...

bool	isNone () const
	returns true if the node is a "none" object More...

bool	isReal () const
	returns true if the node is a floating-point number More...

bool	isSeq () const
	returns true if the node is a sequence More...

bool	isString () const
	returns true if the node is a text string More...

std::vector< String >	keys () const
	Returns keys of a mapping node. More...

Mat	mat () const
	Simplified reading API to use with bindings. More...

std::string	name () const
	returns the node name or an empty string if the node is nameless More...

	operator double () const
	returns the node content as double More...

	operator float () const
	returns the node content as float More...

	operator std::string () const
	returns the node content as text string More...

FileNode	operator[] (const String &nodename) const
	Returns element of a mapping node or a sequence node. More...

FileNode	operator[] (const char *nodename) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

FileNode	operator[] (int i) const
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...

uchar *	ptr ()

const uchar *	ptr () const

size_t	rawSize () const
	returns raw size of the FileNode in bytes More...

void	readRaw (const String &fmt, void *vec, size_t len) const
	Reads node elements to the buffer with the specified format. More...

double	real () const
	Simplified reading API to use with bindings. More...

void	setValue (int type, const void *value, int len=-1)
	Internal method used when reading FileStorage. More...

size_t	size () const
	returns the number of elements in the node, if it is a sequence or mapping, or 1 otherwise. More...

std::string	string () const
	Simplified reading API to use with bindings. More...

int	type () const
	Returns type of the node. More...

Static Public Member Functions
static bool	isCollection (int flags)

static bool	isEmptyCollection (int flags)

static bool	isFlow (int flags)

static bool	isMap (int flags)

static bool	isSeq (int flags)

Public Attributes
size_t	blockIdx

const FileStorage *	fs

size_t	ofs

Related Functions
(Note that these are not member functions.)

void	read (const FileNode &node, int &value, int default_value)

void	read (const FileNode &node, float &value, float default_value)

void	read (const FileNode &node, double &value, double default_value)

void	read (const FileNode &node, std::string &value, const std::string &default_value)

void	read (const FileNode &node, Mat &mat, const Mat &default_mat=Mat())

void	read (const FileNode &node, SparseMat &mat, const SparseMat &default_mat=SparseMat())

void	read (const FileNode &node, KeyPoint &value, const KeyPoint &default_value)

void	read (const FileNode &node, DMatch &value, const DMatch &default_value)

template<typename _Tp >
static void	read (const FileNode &node, Point_< _Tp > &value, const Point_< _Tp > &default_value)

template<typename _Tp >
static void	read (const FileNode &node, Point3_< _Tp > &value, const Point3_< _Tp > &default_value)

template<typename _Tp >
static void	read (const FileNode &node, Size_< _Tp > &value, const Size_< _Tp > &default_value)

template<typename _Tp >
static void	read (const FileNode &node, Complex< _Tp > &value, const Complex< _Tp > &default_value)

template<typename _Tp >
static void	read (const FileNode &node, Rect_< _Tp > &value, const Rect_< _Tp > &default_value)

template<typename _Tp , int cn>
static void	read (const FileNode &node, Vec< _Tp, cn > &value, const Vec< _Tp, cn > &default_value)

template<typename _Tp , int m, int n>
static void	read (const FileNode &node, Matx< _Tp, m, n > &value, const Matx< _Tp, m, n > &default_matx=Matx< _Tp, m, n >())

template<typename _Tp >
static void	read (const FileNode &node, Scalar_< _Tp > &value, const Scalar_< _Tp > &default_value)

static void	read (const FileNode &node, Range &value, const Range &default_value)


static void	read (const FileNode &node, bool &value, bool default_value)

static void	read (const FileNode &node, uchar &value, uchar default_value)

static void	read (const FileNode &node, schar &value, schar default_value)

static void	read (const FileNode &node, ushort &value, ushort default_value)

static void	read (const FileNode &node, short &value, short default_value)

template<typename _Tp >
static void	read (FileNodeIterator &it, std::vector< _Tp > &vec, size_t maxCount=(size_t) INT_MAX)

template<typename _Tp , typename std::enable_if< std::is_enum< _Tp >::value >::type * = nullptr>
static void	read (const FileNode &node, _Tp &value, const _Tp &default_value=static_cast< _Tp >(0))

template<typename _Tp >
static void	read (const FileNode &node, std::vector< _Tp > &vec, const std::vector< _Tp > &default_value=std::vector< _Tp >())

static void	read (const FileNode &node, std::vector< KeyPoint > &vec, const std::vector< KeyPoint > &default_value)

static void	read (const FileNode &node, std::vector< DMatch > &vec, const std::vector< DMatch > &default_value)


template<typename _Tp >
static void	operator>> (const FileNode &n, _Tp &value)
	Reads data from a file storage. More...

template<typename _Tp >
static void	operator>> (const FileNode &n, std::vector< _Tp > &vec)
	Reads data from a file storage. More...

static void	operator>> (const FileNode &n, KeyPoint &kpt)
	Reads KeyPoint from a file storage. More...

static void	operator>> (const FileNode &n, DMatch &m)
	Reads DMatch from a file storage. More...

Detailed Description

File Storage Node class.

The node is used to store each and every element of the file storage opened for reading. When XML/YAML file is read, it is first parsed and stored in the memory as a hierarchical collection of nodes. Each node can be a "leaf" that is contain a single number or a string, or be a collection of other nodes. There can be named collections (mappings) where each element has a name and it is accessed by a name, and ordered collections (sequences) where elements do not have names but rather accessed by index. Type of the file node can be determined using FileNode::type method.

Note that file nodes are only used for navigating file storages opened for reading. When a file storage is opened for writing, no data is stored in memory after it is written.

Examples:: samples/cpp/filestorage.cpp.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

type of the file storage node

Enumerator
NONE	empty node
INT	an integer
REAL	floating-point number
FLOAT	synonym or REAL
STR	text string in UTF-8 encoding
STRING	synonym for STR
SEQ	sequence
MAP	mapping
TYPE_MASK
FLOW	compact representation of a sequence or mapping. Used only by YAML writer
UNIFORM	if set, means that all the collection elements are numbers of the same type (real's or int's). UNIFORM is used only when reading FileStorage; FLOW is used only when writing. So they share the same bit
EMPTY	empty structure (sequence or mapping)
NAMED	the node has a name (i.e. it is element of a mapping).

Constructor & Destructor Documentation

◆ FileNode() [1/3]

cv::FileNode::FileNode ( )

The constructors.

These constructors are used to create a default file node, construct it from obsolete structures or from the another file node.

◆ FileNode() [2/3]

cv::FileNode::FileNode	(	const FileStorage *	fs,
		size_t	blockIdx,
		size_t	ofs
	)

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

Parameters

fs	Pointer to the file storage structure.
blockIdx	Index of the memory block where the file node is stored
ofs	Offset in bytes from the beginning of the serialized storage

◆ FileNode() [3/3]

cv::FileNode::FileNode ( const FileNode & node )

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

Parameters

node	File node to be used as initialization for the created file node.

Member Function Documentation

◆ begin()

FileNodeIterator cv::FileNode::begin ( ) const

returns iterator pointing to the first node element

Examples:: samples/cpp/filestorage.cpp.

Referenced by operator>>(), and read().

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◆ empty()

bool cv::FileNode::empty ( ) const

returns true if the node is empty

Examples:: samples/cpp/filestorage.cpp.

Referenced by cv::Algorithm::load(), cv::Algorithm::loadFromString(), and read().

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◆ end()

FileNodeIterator cv::FileNode::end ( ) const

returns iterator pointing to the element following the last node element

Examples:: samples/cpp/filestorage.cpp.

◆ isCollection()

static bool cv::FileNode::isCollection ( int flags )

static

◆ isEmptyCollection()

static bool cv::FileNode::isEmptyCollection ( int flags )

static

◆ isFlow()

static bool cv::FileNode::isFlow ( int flags )

static

◆ isInt()

bool cv::FileNode::isInt ( ) const

returns true if the node is an integer

◆ isMap() [1/2]

bool cv::FileNode::isMap ( ) const

returns true if the node is a mapping

◆ isMap() [2/2]

static bool cv::FileNode::isMap ( int flags )

static

◆ isNamed()

bool cv::FileNode::isNamed ( ) const

returns true if the node has a name

◆ isNone()

bool cv::FileNode::isNone ( ) const

returns true if the node is a "none" object

◆ isReal()

bool cv::FileNode::isReal ( ) const

returns true if the node is a floating-point number

◆ isSeq() [1/2]

bool cv::FileNode::isSeq ( ) const

returns true if the node is a sequence

◆ isSeq() [2/2]

static bool cv::FileNode::isSeq ( int flags )

static

◆ isString()

bool cv::FileNode::isString ( ) const

returns true if the node is a text string

◆ keys()

std::vector<String> cv::FileNode::keys ( ) const

Returns keys of a mapping node.

Returns: Keys of a mapping node.

◆ mat()

Mat cv::FileNode::mat ( ) const

Simplified reading API to use with bindings.

◆ name()

std::string cv::FileNode::name ( ) const

returns the node name or an empty string if the node is nameless

◆ operator double()

cv::FileNode::operator double ( ) const

returns the node content as double

◆ operator float()

cv::FileNode::operator float ( ) const

returns the node content as float

◆ operator std::string()

cv::FileNode::operator std::string ( ) const

inline

returns the node content as text string

References CV_WRAP, and operator std::string().

Referenced by operator std::string().

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◆ operator[]() [1/3]

FileNode cv::FileNode::operator[] ( const String & nodename ) const

Returns element of a mapping node or a sequence node.

Parameters

nodename Name of an element in the mapping node.

Returns: Returns the element with the given identifier.

◆ operator[]() [2/3]

FileNode cv::FileNode::operator[] ( const char * nodename ) const

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

Parameters

nodename Name of an element in the mapping node.

◆ operator[]() [3/3]

FileNode cv::FileNode::operator[] ( int i ) const

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

Parameters

i	Index of an element in the sequence node.

◆ ptr() [1/2]

uchar* cv::FileNode::ptr ( )

◆ ptr() [2/2]

const uchar* cv::FileNode::ptr ( ) const

◆ rawSize()

size_t cv::FileNode::rawSize ( ) const

returns raw size of the FileNode in bytes

◆ readRaw()

void cv::FileNode::readRaw	(	const String &	fmt,
		void *	vec,
		size_t	len
	)		const

Reads node elements to the buffer with the specified format.

Usually it is more convenient to use operator >> instead of this method.

Parameters

fmt	Specification of each array element. See format specification
vec	Pointer to the destination array.
len	Number of bytes to read (buffer size limit). If it is greater than number of remaining elements then all of them will be read.

◆ real()

double cv::FileNode::real ( ) const

Simplified reading API to use with bindings.

◆ setValue()

void cv::FileNode::setValue	(	int	type,
		const void *	value,
		int	len = `-1`
	)

Internal method used when reading FileStorage.

Sets the type (int, real or string) and value of the previously created node.

◆ size()

size_t cv::FileNode::size ( ) const

returns the number of elements in the node, if it is a sequence or mapping, or 1 otherwise.

◆ string()

std::string cv::FileNode::string ( ) const

Simplified reading API to use with bindings.

◆ type()

int cv::FileNode::type ( ) const

Returns type of the node.

Returns: Type of the node. See FileNode::Type

Examples:: samples/cpp/filestorage.cpp.

Friends And Related Function Documentation

◆ operator>>() [1/4]

template<typename _Tp >

static void operator>>	(	const FileNode &	n,
		_Tp &	value
	)

◆ operator>>() [2/4]

template<typename _Tp >

static void operator>>	(	const FileNode &	n,
		std::vector< _Tp > &	vec
	)

References begin().

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◆ operator>>() [3/4]

static void operator>>	(	const FileNode &	n,
		KeyPoint &	kpt
	)

References cv::KeyPoint::angle, begin(), cv::KeyPoint::class_id, cv::KeyPoint::octave, cv::operator>>(), cv::KeyPoint::pt, cv::KeyPoint::response, cv::KeyPoint::size, cv::Point_< _Tp >::x, and cv::Point_< _Tp >::y.

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◆ operator>>() [4/4]

static void operator>>	(	const FileNode &	n,
		DMatch &	m
	)

References begin(), cv::DMatch::distance, cv::DMatch::imgIdx, cv::operator!=(), cv::operator==(), cv::DMatch::queryIdx, and cv::DMatch::trainIdx.

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◆ read() [1/27]

void read	(	const FileNode &	node,
		int &	value,
		int	default_value
	)

void read	(	const FileNode &	node,
		float &	value,
		float	default_value
	)

void read	(	const FileNode &	node,
		double &	value,
		double	default_value
	)

void read	(	const FileNode &	node,
		std::string &	value,
		const std::string &	default_value
	)

void read	(	const FileNode &	node,
		Mat &	mat,
		const Mat &	default_mat = `Mat()`
	)

void read	(	const FileNode &	node,
		SparseMat &	mat,
		const SparseMat &	default_mat = `SparseMat()`
	)

void read	(	const FileNode &	node,
		KeyPoint &	value,
		const KeyPoint &	default_value
	)

void read	(	const FileNode &	node,
		DMatch &	value,
		const DMatch &	default_value
	)

template<typename _Tp >

static void read	(	const FileNode &	node,
		Point_< _Tp > &	value,
		const Point_< _Tp > &	default_value
	)

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◆ read() [10/27]

template<typename _Tp >

static void read	(	const FileNode &	node,
		Point3_< _Tp > &	value,
		const Point3_< _Tp > &	default_value
	)

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◆ read() [11/27]

template<typename _Tp >

static void read	(	const FileNode &	node,
		Size_< _Tp > &	value,
		const Size_< _Tp > &	default_value
	)

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◆ read() [12/27]

template<typename _Tp >

static void read	(	const FileNode &	node,
		Complex< _Tp > &	value,
		const Complex< _Tp > &	default_value
	)

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◆ read() [13/27]

template<typename _Tp >

static void read	(	const FileNode &	node,
		Rect_< _Tp > &	value,
		const Rect_< _Tp > &	default_value
	)

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◆ read() [14/27]

template<typename _Tp , int cn>

static void read	(	const FileNode &	node,
		Vec< _Tp, cn > &	value,
		const Vec< _Tp, cn > &	default_value
	)

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◆ read() [15/27]

template<typename _Tp , int m, int n>

static void read	(	const FileNode &	node,
		Matx< _Tp, m, n > &	value,
		const Matx< _Tp, m, n > &	default_matx = `Matx<_Tp, m, n>()`
	)

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◆ read() [16/27]

template<typename _Tp >

static void read	(	const FileNode &	node,
		Scalar_< _Tp > &	value,
		const Scalar_< _Tp > &	default_value
	)

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◆ read() [17/27]

static void read	(	const FileNode &	node,
		Range &	value,
		const Range &	default_value
	)

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◆ read() [18/27]

static void read	(	const FileNode &	node,
		bool &	value,
		bool	default_value
	)

static void read	(	const FileNode &	node,
		uchar &	value,
		uchar	default_value
	)

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◆ read() [20/27]

static void read	(	const FileNode &	node,
		schar &	value,
		schar	default_value
	)

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◆ read() [21/27]

static void read	(	const FileNode &	node,
		ushort &	value,
		ushort	default_value
	)

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◆ read() [22/27]

static void read	(	const FileNode &	node,
		short &	value,
		short	default_value
	)

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◆ read() [23/27]

template<typename _Tp >

static void read	(	FileNodeIterator &	it,
		std::vector< _Tp > &	vec,
		size_t	maxCount = `(size_t)INT_MAX`
	)

template<typename _Tp , typename std::enable_if< std::is_enum< _Tp >::value >::type * = nullptr>

static void read	(	const FileNode &	node,
		_Tp &	value,
		const _Tp &	default_value = `static_cast<_Tp>(0)`
	)

template<typename _Tp >

static void read	(	const FileNode &	node,
		std::vector< _Tp > &	vec,
		const std::vector< _Tp > &	default_value = `std::vector<_Tp>()`
	)

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◆ read() [26/27]

static void read	(	const FileNode &	node,
		std::vector< KeyPoint > &	vec,
		const std::vector< KeyPoint > &	default_value
	)

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◆ read() [27/27]

static void read	(	const FileNode &	node,
		std::vector< DMatch > &	vec,
		const std::vector< DMatch > &	default_value
	)

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Member Data Documentation

◆ blockIdx

size_t cv::FileNode::blockIdx

◆ fs

const FileStorage* cv::FileNode::fs

◆ ofs

size_t cv::FileNode::ofs

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

opencv2/core/persistence.hpp

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Related Functions

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ FileNode() [1/3]

◆ FileNode() [2/3]

◆ FileNode() [3/3]

Member Function Documentation

◆ begin()

◆ empty()

◆ end()

◆ isCollection()

◆ isEmptyCollection()

◆ isFlow()

◆ isInt()

◆ isMap() [1/2]

◆ isMap() [2/2]

◆ isNamed()

◆ isNone()

◆ isReal()

◆ isSeq() [1/2]

◆ isSeq() [2/2]

◆ isString()

◆ keys()

◆ mat()

◆ name()

◆ operator double()

◆ operator float()

◆ operator std::string()

◆ operator[]() [1/3]

◆ operator[]() [2/3]

◆ operator[]() [3/3]

◆ ptr() [1/2]

◆ ptr() [2/2]

◆ rawSize()

◆ readRaw()

◆ real()

◆ setValue()

◆ size()

◆ string()

◆ type()

Friends And Related Function Documentation

◆ operator>>() [1/4]

◆ operator>>() [2/4]

◆ operator>>() [3/4]

◆ operator>>() [4/4]

◆ read() [1/27]

◆ read() [2/27]

◆ read() [3/27]

◆ read() [4/27]

◆ read() [5/27]

◆ read() [6/27]

◆ read() [7/27]

◆ read() [8/27]

◆ read() [9/27]

◆ read() [10/27]

◆ read() [11/27]

◆ read() [12/27]

◆ read() [13/27]

◆ read() [14/27]

◆ read() [15/27]

◆ read() [16/27]

◆ read() [17/27]

◆ read() [18/27]

◆ read() [19/27]

◆ read() [20/27]

◆ read() [21/27]

◆ read() [22/27]

◆ read() [23/27]

◆ read() [24/27]

◆ read() [25/27]

◆ read() [26/27]

◆ read() [27/27]

Member Data Documentation

◆ blockIdx