mrpt::utils::CFileInputStream Class Reference

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Detailed Description

This CStream derived class allow using a file as a read-only, binary stream.

See also:

CStream, CFileStream, CFileGZInputStream

#include <mrpt/utils/CFileInputStream.h>

Inheritance diagram for mrpt::utils::CFileInputStream:

List of all members.

Public Types
enum	TSeekOrigin { sFromBeginning = 0, sFromCurrent = 1, sFromEnd = 2 }
	Used in CStream::Seek. More...
Public Member Functions
	CFileInputStream (const std::string &fileName)
	Constructor.
	CFileInputStream ()
	Default constructor.
bool	open (const std::string &fileName)
	Open a file for reading.
void	close ()
	Close the stream.
virtual	~CFileInputStream ()
	Destructor.
bool	fileOpenCorrectly ()
	Says if file was open successfully or not.
bool	checkEOF ()
	Will be true if EOF has been already reached.
uint64_t	Seek (long Offset, CStream::TSeekOrigin Origin=sFromBeginning)
	Method for moving to a specified position in the streamed resource.
uint64_t	getTotalBytesCount ()
	Method for getting the total number of bytes in the buffer.
uint64_t	getPosition ()
	Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one.
bool	readLine (std::string &str)
	Reads one string line from the file (until a new-line character)
size_t	ReadBuffer (void *Buffer, size_t Count)
	Reads a block of bytes from the stream into Buffer Exceptions: std::exception On any error, or if ZERO bytes are read.
template<typename T >
size_t	ReadBufferFixEndianness (T *ptr, size_t ElementCount)
	Reads a sequence of elemental datatypes, taking care of reordering their bytes from the MRPT stream standard (little endianness) to the format of the running architecture.
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).
void	WriteBuffer (const void *Buffer, size_t Count)
	Writes a block of bytes to the stream from Buffer.
template<typename T >
void	WriteBufferFixEndianness (const T *ptr, size_t ElementCount)
	Writes a sequence of elemental datatypes, taking care of reordering their bytes from the running architecture to MRPT stream standard (little endianness).
size_t	CopyFrom (CStream *Source, size_t Count)
	Copies a specified number of bytes from one stream to another.
void	WriteObject (const CSerializable *o)
	Writes an object to the stream.
CSerializablePtr	ReadObject ()
	Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object.
void	ReadObject (CSerializable *existingObj)
	Reads an object from stream, where its class must be the same as the supplied object, where the loaded object will be stored in.
CStream &	operator<< (const CSerializablePtr &pObj)
	Write an object to a stream in the binary MRPT format.
CStream &	operator<< (const CSerializable &obj)
	Write an object to a stream in the binary MRPT format.
CStream &	operator>> (CSerializablePtr &pObj)
CStream &	operator>> (CSerializable &obj)
virtual int	printf (const char *fmt,...) MRPT_printf_format_check(2
	Writes a string to the stream in a textual form.
template<typename T >
virtual int void	printf_vector (const char *fmt, const std::vector< T > &V)
	Prints a vector in the format [A,B,C,...] using CStream::printf, and the fmt string for each vector element.
void	sendMessage (const utils::CMessage &msg)
	Send a message to the device.
bool	receiveMessage (utils::CMessage &msg)
	Tries to receive a message from the device.
bool	getline (std::string &out_str)
	Reads from the stream until a ' ' character is found ('' characters are ignored).
Protected Member Functions
size_t	Read (void *Buffer, size_t Count)
	Method responsible for reading from the stream.
size_t	Write (const void *Buffer, size_t Count)
	Method responsible for writing to the stream.
Private Attributes
std::ifstream	m_if
	The actual input file stream.

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Member Enumeration Documentation

enum mrpt::utils::CStream::TSeekOrigin [inherited]

Used in CStream::Seek.

Enumerator:

sFromBeginning
sFromCurrent
sFromEnd

Definition at line 60 of file CStream.h.

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Constructor & Destructor Documentation

mrpt::utils::CFileInputStream::CFileInputStream

(

const std::string &

fileName

)

Constructor.

Parameters:

fileName

The file to be open in this stream

Exceptions:

std::exception

On error trying to open the file.

mrpt::utils::CFileInputStream::CFileInputStream

(

)

Default constructor.

virtual mrpt::utils::CFileInputStream::~CFileInputStream

(

)

[virtual]

Destructor.

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Member Function Documentation

bool mrpt::utils::CFileInputStream::checkEOF

(

)

Will be true if EOF has been already reached.

void mrpt::utils::CFileInputStream::close

(

)

Close the stream.

size_t mrpt::utils::CStream::CopyFrom	(	CStream *	Source,
		size_t	Count
	)		[inherited]

Copies a specified number of bytes from one stream to another.

bool mrpt::utils::CFileInputStream::fileOpenCorrectly

(

)

Says if file was open successfully or not.

bool mrpt::utils::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.

uint64_t mrpt::utils::CFileInputStream::getPosition

(

)

[virtual]

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

Implements mrpt::utils::CStream.

uint64_t mrpt::utils::CFileInputStream::getTotalBytesCount

(

)

[virtual]

Method for getting the total number of bytes in the buffer.

Implements mrpt::utils::CStream.

bool mrpt::utils::CFileInputStream::open

(

const std::string &

fileName

)

Open a file for reading.

Parameters:

fileName

The file to be open in this stream

Returns:

true on success.

CStream& mrpt::utils::CStream::operator<<

(

const CSerializablePtr &

pObj

)

[inherited]

Write an object to a stream in the binary MRPT format.

CStream& mrpt::utils::CStream::operator<<

(

const CSerializable &

obj

)

[inherited]

Write an object to a stream in the binary MRPT format.

CStream& mrpt::utils::CStream::operator>>

(

CSerializablePtr &

pObj

)

[inherited]

CStream& mrpt::utils::CStream::operator>>

(

CSerializable &

obj

)

[inherited]

virtual int mrpt::utils::CStream::printf	(	const char *	fmt,
			...
	)		[virtual, inherited]

Writes a string to the stream in a textual form.

See also:

CStdOutStream

template<typename T >

virtual int void mrpt::utils::CStream::printf_vector	(	const char *	fmt,
		const std::vector< T > &	V
	)		[inline, inherited]

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

Definition at line 219 of file CStream.h.

size_t mrpt::utils::CFileInputStream::Read	(	void *	Buffer,
		size_t	Count
	)		[protected, virtual]

Method responsible for reading from the stream.

Implements mrpt::utils::CStream.

size_t mrpt::utils::CStream::ReadBuffer	(	void *	Buffer,
		size_t	Count
	)		[inherited]

Reads a block of bytes from the stream into Buffer

Exceptions:

std::exception

On any error, or if ZERO bytes are read.

Returns:

The amound of bytes actually read.

Note:

This method is endianness-dependent.

See also:

ReadBufferImmediate ; Important, see: ReadBufferFixEndianness,

template<typename T >

size_t mrpt::utils::CStream::ReadBufferFixEndianness	(	T *	ptr,
		size_t	ElementCount
	)		[inline, inherited]

Reads a sequence of elemental datatypes, taking care of reordering their bytes from the MRPT stream standard (little endianness) to the format of the running architecture.

Parameters:

ElementCount	The number of elements (not bytes) to read.
ptr	A pointer to the first output element in an array (or std::vector<>, etc...).

Returns:

The amound of *bytes* (not elements) actually read (under error situations, the last element may be invalid if the data stream abruptly ends). Example of usage:

   uint32_t  N;
   s >> N;
   vector<float>  vec(N);
   if (N) 
     s.ReadBufferFixEndianness<float>(&vec[0],N);

Exceptions:

std::exception

On any error, or if ZERO bytes are read.

See also:

ReadBufferFixEndianness, ReadBuffer

Definition at line 109 of file CStream.h.

References mrpt::utils::reverseBytesInPlace().

Referenced by mrpt::math::operator>>().

virtual size_t mrpt::utils::CStream::ReadBufferImmediate	(	void *	Buffer,
		size_t	Count
	)		[inline, virtual, inherited]

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::hwdrivers::CInterfaceFTDI.

Definition at line 127 of file CStream.h.

bool mrpt::utils::CFileInputStream::readLine

(

std::string &

str

)

Reads one string line from the file (until a new-line character)

Returns:

true if a line has been read, false on EOF or error.

CSerializablePtr mrpt::utils::CStream::ReadObject

(

)

[inherited]

Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object.

Exceptions:

std::exception	On I/O error or undefined class.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

Referenced by mrpt::math::operator>>().

void mrpt::utils::CStream::ReadObject

(

CSerializable *

existingObj

)

[inherited]

Reads an object from stream, where its class must be the same as the supplied object, where the loaded object will be stored in.

Exceptions:

std::exception	On I/O error or different class found.
mrpt::utils::CExceptionEOF	On an End-Of-File condition found at a correct place: an EOF that abruptly finishes in the middle of one object raises a plain std::exception instead.

bool mrpt::utils::CStream::receiveMessage

(

utils::CMessage &

msg

)

[inherited]

Tries to receive a message from the device.

Exceptions:

std::exception

On communication errors

Returns:

True if successful, false if there is no new data from the device (but communications seem to work fine)

See also:

The frame format is described in sendMessage()

uint64_t mrpt::utils::CFileInputStream::Seek	(	long	Offset,
		CStream::TSeekOrigin	Origin = sFromBeginning
	)		[virtual]

Method for moving to a specified position in the streamed resource.

See documentation of CStream::Seek

Implements mrpt::utils::CStream.

void mrpt::utils::CStream::sendMessage

(

const utils::CMessage &

msg

)

[inherited]

Send a message to the device.

Note that only the low byte from the "type" field will be used.

For frames of size < 255 the frame format is an array of bytes in this order:

  <START_FLAG> <HEADER> <LENGTH> <BODY> <END_FLAG>
        <START_FLAG>    = 0x69
        <HEADER>                = A header byte
        <LENGHT>                = Number of bytes of BODY
        <BODY>                  = N x bytes
        <END_FLAG>              = 0X96
  Total length  =       <LENGTH> + 4

For frames of size > 255 the frame format is an array of bytes in this order:

  <START_FLAG> <HEADER> <HIBYTE(LENGTH)> <LOBYTE(LENGTH)> <BODY> <END_FLAG>
        <START_FLAG>    = 0x79
        <HEADER>                = A header byte
        <LENGHT>                = Number of bytes of BODY
        <BODY>                  = N x bytes
        <END_FLAG>              = 0X96
  Total length  =       <LENGTH> + 5

Exceptions:

std::exception

On communication errors

size_t mrpt::utils::CFileInputStream::Write	(	const void *	Buffer,
		size_t	Count
	)		[protected, 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::utils::CStream.

void mrpt::utils::CStream::WriteBuffer	(	const void *	Buffer,
		size_t	Count
	)		[inherited]

Writes a block of bytes to the stream from Buffer.

Exceptions:

std::exception

On any error

See also:

Important, see: WriteBufferFixEndianness

Note:

This method is endianness-dependent.

template<typename T >

void mrpt::utils::CStream::WriteBufferFixEndianness	(	const T *	ptr,
		size_t	ElementCount
	)		[inline, inherited]

Writes a sequence of elemental datatypes, taking care of reordering their bytes from the running architecture to MRPT stream standard (little endianness).

Parameters:

ElementCount	The number of elements (not bytes) to write.
ptr	A pointer to the first input element in an array (or std::vector<>, etc...). Example of usage: vector<float> vec = ... uint32_t N = vec.size(); s << N if (N) s.WriteBufferFixEndianness<float>(&vec[0],N);

Exceptions:

std::exception

On any error

See also:

WriteBuffer

Definition at line 153 of file CStream.h.

void mrpt::utils::CStream::WriteObject

(

const CSerializable *

o

)

[inherited]

Writes an object to the stream.

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Member Data Documentation

std::ifstream mrpt::utils::CFileInputStream::m_if [private]

The actual input file stream.

Definition at line 60 of file CFileInputStream.h.