Detailed Description

This CStream derived class allow using a memory buffer as a CStream.

This class is useful for storing any required set of variables or objects, and then read them to other objects, or storing them to a file, for example.

See also: CStream

Definition at line 26 of file io/CMemoryStream.h.

#include <mrpt/io/CMemoryStream.h>

Inheritance diagram for mrpt::io::CMemoryStream:

Public Types
enum	TSeekOrigin { sFromBeginning = 0, sFromCurrent = 1, sFromEnd = 2 }
	Used in CStream::Seek. More...

Public Member Functions
size_t	Read (void *Buffer, size_t Count) override
	Introduces a pure virtual method responsible for reading from the stream. More...

size_t	Write (const void *Buffer, size_t Count) override
	Introduces a pure virtual method responsible for writing to the stream. More...

	CMemoryStream ()=default
	Default constructor. More...

	CMemoryStream (const void *data, const uint64_t nBytesInData)
	Constructor to initilize the data in the stream from a block of memory (which is copied), and sets the current stream position at the beginning of the data. More...

void	assignMemoryNotOwn (const void *data, const uint64_t nBytesInData)
	Initilize the data in the stream from a block of memory which is NEITHER OWNED NOR COPIED by the object, so it must exist during the whole live of the object. More...

	~CMemoryStream () override
	Destructor. More...

void	Clear ()
	Clears the memory buffer. More...

void	changeSize (uint64_t newSize)
	Change size. More...

uint64_t	Seek (int64_t Offset, CStream::TSeekOrigin Origin=sFromBeginning) override
	Introduces a pure virtual method for moving to a specified position in the streamed resource. More...

uint64_t	getTotalBytesCount () const override
	Returns the total size of the internal buffer. More...

uint64_t	getPosition () const override
	Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one. More...

void *	getRawBufferData ()
	Method for getting a pointer to the raw stored data. More...

const void *	getRawBufferData () const

bool	saveBufferToFile (const std::string &file_name)
	Saves the entire buffer to a file. More...

bool	loadBufferFromFile (const std::string &file_name)
	Loads the entire buffer from a file *. More...

void	setAllocBlockSize (uint64_t alloc_block_size)
	Change the size of the additional memory block that is reserved whenever the current block runs too short (default=0x10000 bytes) More...

virtual size_t	ReadBufferImmediate (void *Buffer, size_t Count)
	Reads a block of bytes from the stream into Buffer, and returns the amound of bytes actually read, without waiting for more extra bytes to arrive (just those already enqued in the stream). More...

virtual int	printf (const char *fmt,...) MRPT_printf_format_check(2
	Writes a string to the stream in a textual form. More...

template<typename CONTAINER_TYPE >
virtual int void	printf_vector (const char *fmt, const CONTAINER_TYPE &V, char separator=',')
	Prints a vector in the format [A,B,C,...] using CStream::printf, and the fmt string for each vector element `T`. More...

bool	getline (std::string &out_str)
	Reads from the stream until a ' ' character is found ('' characters are ignored). More...

Protected Member Functions
void	resize (uint64_t newSize)
	Resizes the internal buffer size. More...

Protected Attributes
void_ptr_noncopy	m_memory {nullptr}
	Internal data. More...

uint64_t	m_size {0}

uint64_t	m_position {0}

uint64_t	m_bytesWritten {0}

uint64_t	m_alloc_block_size {0x1000}

bool	m_read_only {false}
	If the memory block does not belong to the object. More...

Member Enumeration Documentation

◆ TSeekOrigin

enum mrpt::io::CStream::TSeekOrigin

inherited

Used in CStream::Seek.

Enumerator
sFromBeginning
sFromCurrent
sFromEnd

Definition at line 32 of file io/CStream.h.

Constructor & Destructor Documentation

◆ CMemoryStream() [1/2]

mrpt::io::CMemoryStream::CMemoryStream ( )

default

Default constructor.

◆ CMemoryStream() [2/2]

CMemoryStream::CMemoryStream	(	const void *	data,
		const uint64_t	nBytesInData
	)

Constructor to initilize the data in the stream from a block of memory (which is copied), and sets the current stream position at the beginning of the data.

See also: assignMemoryNotOwn

Definition at line 22 of file CMemoryStream.cpp.

References ASSERT_, mrpt::non_copiable_ptr_basic< T >::get(), m_bytesWritten, m_memory, mrpt::system::os::memcpy(), MRPT_END, MRPT_START, and resize().

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◆ ~CMemoryStream()

CMemoryStream::~CMemoryStream ( )

override

Destructor.

Definition at line 47 of file CMemoryStream.cpp.

References m_read_only, and resize().

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Member Function Documentation

◆ assignMemoryNotOwn()

void CMemoryStream::assignMemoryNotOwn	(	const void *	data,
		const uint64_t	nBytesInData
	)

Initilize the data in the stream from a block of memory which is NEITHER OWNED NOR COPIED by the object, so it must exist during the whole live of the object.

After assigning a block of data with this method, the object becomes "read-only", so further attempts to change the size of the buffer will raise an exception. This method resets the write and read positions to the beginning.

Definition at line 36 of file CMemoryStream.cpp.

References Clear(), m_bytesWritten, m_memory, m_position, m_read_only, m_size, and mrpt::non_copiable_ptr_basic< T >::set().

Referenced by mrpt::obs::stock_observations::exampleImage(), and mrpt::serialization::mrpt_recv_from_zmq_buf().

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◆ changeSize()

void CMemoryStream::changeSize ( uint64_t newSize )

Change size.

This would be rarely used. Use ">>" operators for writing to stream

See also: Stream

Definition at line 161 of file CMemoryStream.cpp.

References resize().

Referenced by mrpt::img::CImage::serializeFrom().

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◆ Clear()

void CMemoryStream::Clear ( )

Clears the memory buffer.

Definition at line 143 of file CMemoryStream.cpp.

References m_bytesWritten, m_memory, m_position, m_read_only, m_size, and resize().

Referenced by assignMemoryNotOwn(), loadBufferFromFile(), and mrpt::serialization::mrpt_recv_from_zmq_buf().

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◆ getline()

bool CStream::getline ( std::string & out_str )

inherited

Reads from the stream until a '
' character is found ('' characters are ignored).

Returns: false on EOF or any other read error.

Definition at line 69 of file CStream.cpp.

◆ getPosition()

uint64_t CMemoryStream::getPosition ( ) const

overridevirtual

Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one.

Implements mrpt::io::CStream.

Definition at line 142 of file CMemoryStream.cpp.

References m_position.

◆ getRawBufferData() [1/2]

void * CMemoryStream::getRawBufferData ( )

Method for getting a pointer to the raw stored data.

The lenght in bytes is given by getTotalBytesCount

Definition at line 159 of file CMemoryStream.cpp.

References mrpt::non_copiable_ptr_basic< T >::get(), and m_memory.

Referenced by mrpt::img::CImage::serializeFrom(), and mrpt::img::CImage::serializeTo().

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◆ getRawBufferData() [2/2]

const void * CMemoryStream::getRawBufferData ( ) const

Definition at line 160 of file CMemoryStream.cpp.

References mrpt::non_copiable_ptr_basic< T >::get(), and m_memory.

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◆ getTotalBytesCount()

uint64_t CMemoryStream::getTotalBytesCount ( ) const

overridevirtual

Returns the total size of the internal buffer.

Implements mrpt::io::CStream.

Definition at line 141 of file CMemoryStream.cpp.

References m_bytesWritten.

Referenced by mrpt::serialization::mrpt_recv_from_zmq_buf(), mrpt::serialization::mrpt_send_to_zmq(), saveBufferToFile(), and mrpt::img::CImage::serializeTo().

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◆ loadBufferFromFile()

bool CMemoryStream::loadBufferFromFile ( const std::string & file_name )

Loads the entire buffer from a file *.

Returns: true on success, false on error

Definition at line 179 of file CMemoryStream.cpp.

References Clear(), mrpt::non_copiable_ptr_basic< T >::get(), mrpt::io::CFileInputStream::getTotalBytesCount(), m_bytesWritten, m_memory, m_position, mrpt::io::CFileInputStream::Read(), and resize().

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◆ printf()

int CStream::printf	(	const char *	fmt,
			...
	)

virtualinherited

Writes a string to the stream in a textual form.

See also: CStdOutStream

Definition at line 30 of file CStream.cpp.

References MRPT_END, MRPT_START, and vsnprintf.

Referenced by mrpt::hmtslam::CTopLCDetector_GridMatching::computeTopologicalObservationModel(), and mrpt::io::CStream::printf_vector().

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◆ printf_vector()

template<typename CONTAINER_TYPE >

virtual int void mrpt::io::CStream::printf_vector	(	const char *	fmt,
		const CONTAINER_TYPE &	V,
		char	separator = `','`
	)

inlineinherited

Prints a vector in the format [A,B,C,...] using CStream::printf, and the fmt string for each vector element T.

Template Parameters

CONTAINER_TYPE can be any vector<T>, deque<T> or alike.

Definition at line 102 of file io/CStream.h.

References mrpt::io::CStream::printf().

Referenced by mrpt::hmtslam::CTopLCDetector_GridMatching::computeTopologicalObservationModel().

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◆ Read()

size_t CMemoryStream::Read	(	void *	Buffer,
		size_t	Count
	)

overridevirtual

Introduces a pure virtual method responsible for reading from the stream.

Implements mrpt::io::CStream.

Definition at line 83 of file CMemoryStream.cpp.

References mrpt::non_copiable_ptr_basic< T >::get(), m_memory, m_position, m_size, mrpt::system::os::memcpy(), and min.

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◆ ReadBufferImmediate()

virtual size_t mrpt::io::CStream::ReadBufferImmediate	(	void *	Buffer,
		size_t	Count
	)

inlinevirtualinherited

Reads a block of bytes from the stream into Buffer, and returns the amound of bytes actually read, without waiting for more extra bytes to arrive (just those already enqued in the stream).

Note that this method will fallback to ReadBuffer() in most CStream classes but in some hardware-related classes.

Exceptions

std::exception On any error, or if ZERO bytes are read.

Reimplemented in mrpt::comms::CInterfaceFTDI.

Definition at line 62 of file io/CStream.h.

References mrpt::io::CStream::Read().

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◆ resize()

void CMemoryStream::resize ( uint64_t newSize )

protected

Resizes the internal buffer size.

Definition at line 56 of file CMemoryStream.cpp.

References ASSERT_, mrpt::non_copiable_ptr_basic< T >::get(), m_bytesWritten, m_memory, m_position, m_read_only, m_size, mrpt::non_copiable_ptr_basic< T >::set(), and THROW_EXCEPTION.

Referenced by changeSize(), Clear(), CMemoryStream(), loadBufferFromFile(), Write(), and ~CMemoryStream().

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◆ saveBufferToFile()

bool CMemoryStream::saveBufferToFile ( const std::string & file_name )

Saves the entire buffer to a file.

Returns: true on success, false on error

Definition at line 162 of file CMemoryStream.cpp.

References mrpt::non_copiable_ptr_basic< T >::get(), getTotalBytesCount(), m_memory, and mrpt::io::CFileOutputStream::Write().

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◆ Seek()

uint64_t CMemoryStream::Seek	(	int64_t	Offset,
		CStream::TSeekOrigin	Origin = `sFromBeginning`
	)

overridevirtual

Introduces a pure virtual method for moving to a specified position in the streamed resource.

he Origin parameter indicates how to interpret the Offset parameter. Origin should be one of the following values:

sFromBeginning (Default) Offset is from the beginning of the resource. Seek moves to the position Offset. Offset must be >= 0.
sFromCurrent Offset is from the current position in the resource. Seek moves to Position + Offset.
sFromEnd Offset is from the end of the resource. Offset must be <= 0 to indicate a number of bytes before the end of the file.
Returns
Seek returns the new value of the Position property.

Implements mrpt::io::CStream.

Definition at line 121 of file CMemoryStream.cpp.

References m_bytesWritten, m_position, m_size, mrpt::io::CStream::sFromBeginning, mrpt::io::CStream::sFromCurrent, and mrpt::io::CStream::sFromEnd.

Referenced by mrpt::obs::gnss::gnss_message_ptr::gnss_message_ptr(), mrpt::hwdrivers::CGPSInterface::implement_parser_NOVATEL_OEM6(), mrpt::serialization::mrpt_recv_from_zmq_buf(), mrpt::obs::gnss::gnss_message_ptr::operator=(), mrpt::nav::CAbstractPTGBasedReactive::performNavigationStep(), mrpt::img::CImage::serializeFrom(), TEST(), and GraphTester< my_graph_t >::test_graph_bin_serialization().

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◆ setAllocBlockSize()

void mrpt::io::CMemoryStream::setAllocBlockSize ( uint64_t alloc_block_size )

inline

Change the size of the additional memory block that is reserved whenever the current block runs too short (default=0x10000 bytes)

Definition at line 94 of file io/CMemoryStream.h.

References ASSERT_, and m_alloc_block_size.

◆ Write()

size_t CMemoryStream::Write	(	const void *	Buffer,
		size_t	Count
	)

overridevirtual

Introduces a pure virtual method responsible for writing to the stream.

Write attempts to write up to Count bytes to Buffer, and returns the number of bytes actually written.

Implements mrpt::io::CStream.

Definition at line 98 of file CMemoryStream.cpp.

References ASSERT_, mrpt::non_copiable_ptr_basic< T >::get(), m_alloc_block_size, m_bytesWritten, m_memory, m_position, m_size, mrpt::system::os::memcpy(), and resize().

Referenced by TEST().

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Member Data Documentation

◆ m_alloc_block_size

uint64_t mrpt::io::CMemoryStream::m_alloc_block_size {0x1000}

protected

Definition at line 36 of file io/CMemoryStream.h.

Referenced by setAllocBlockSize(), and Write().

◆ m_bytesWritten

uint64_t mrpt::io::CMemoryStream::m_bytesWritten {0}

protected

Definition at line 35 of file io/CMemoryStream.h.

Referenced by assignMemoryNotOwn(), Clear(), CMemoryStream(), getTotalBytesCount(), loadBufferFromFile(), resize(), Seek(), and Write().

◆ m_memory

void_ptr_noncopy mrpt::io::CMemoryStream::m_memory {nullptr}

protected

Internal data.

Definition at line 34 of file io/CMemoryStream.h.

Referenced by assignMemoryNotOwn(), Clear(), CMemoryStream(), getRawBufferData(), loadBufferFromFile(), Read(), resize(), saveBufferToFile(), and Write().

◆ m_position

uint64_t mrpt::io::CMemoryStream::m_position {0}

protected

Definition at line 35 of file io/CMemoryStream.h.

Referenced by assignMemoryNotOwn(), Clear(), getPosition(), loadBufferFromFile(), Read(), resize(), Seek(), and Write().

◆ m_read_only

bool mrpt::io::CMemoryStream::m_read_only {false}

protected

If the memory block does not belong to the object.

Definition at line 38 of file io/CMemoryStream.h.

Referenced by assignMemoryNotOwn(), Clear(), resize(), and ~CMemoryStream().

◆ m_size

uint64_t mrpt::io::CMemoryStream::m_size {0}

protected

Definition at line 35 of file io/CMemoryStream.h.

Referenced by assignMemoryNotOwn(), Clear(), Read(), resize(), Seek(), and Write().

Detailed Description

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Member Enumeration Documentation

◆ TSeekOrigin

Constructor & Destructor Documentation

◆ CMemoryStream() [1/2]

◆ CMemoryStream() [2/2]

◆ ~CMemoryStream()

Member Function Documentation

◆ assignMemoryNotOwn()

◆ changeSize()

◆ Clear()

◆ getline()

◆ getPosition()

◆ getRawBufferData() [1/2]

◆ getRawBufferData() [2/2]

◆ getTotalBytesCount()

◆ loadBufferFromFile()

◆ printf()

◆ printf_vector()

◆ Read()

◆ ReadBufferImmediate()

◆ resize()

◆ saveBufferToFile()

◆ Seek()

◆ setAllocBlockSize()

◆ Write()

Member Data Documentation

◆ m_alloc_block_size

◆ m_bytesWritten

◆ m_memory

◆ m_position

◆ m_read_only

◆ m_size