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mrpt::utils::CFileStream Class Reference

Detailed Description

This CStream derived class allow using a file as a read/write binary stream, creating it if the file didn't exist.

The default behavior can be change to open as read, write, read and write,... in the constructor.

See also
CStream, CFileInputStream, CFileOutputStrea, CFileGZInputStream

Definition at line 42 of file CFileStream.h.

#include <mrpt/utils/CFileStream.h>

Inheritance diagram for mrpt::utils::CFileStream:
Inheritance graph
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Public Types

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

Public Member Functions

 CFileStream (const std::string &fileName, TFileOpenModes mode=fomRead|fomWrite)
 Constructor and open a file. More...
 
 CFileStream ()
 Constructor. More...
 
bool open (const std::string &fileName, TFileOpenModes mode=fomRead|fomWrite)
 Opens the file, returning true on success. More...
 
void close ()
 Closes the file. More...
 
virtual ~CFileStream ()
 Destructor. More...
 
bool fileOpenCorrectly ()
 Says if file was open successfully or not. More...
 
bool checkEOF ()
 Will be true if EOF has been already reached. More...
 
uint64_t Seek (uint64_t Offset, CStream::TSeekOrigin Origin=sFromBeginning)
 Method for moving to a specified position in the streamed resource. More...
 
uint64_t getTotalBytesCount ()
 Method for getting the total number of bytes writen to buffer. More...
 
uint64_t getPosition ()
 Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one. More...
 
uint64_t getPositionI ()
 The current Input cursor position, where 0 is the first byte. More...
 
uint64_t getPositionO ()
 The current Input cursor position, where 0 is the first byte. More...
 
bool readLine (std::string &str)
 Reads one string line from the file (until a new-line character) More...
 
size_t ReadBuffer (void *Buffer, size_t Count)
 Reads a block of bytes from the stream into Buffer. More...
 
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. 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...
 
void WriteBuffer (const void *Buffer, size_t Count)
 Writes a block of bytes to the stream from Buffer. More...
 
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). More...
 
size_t CopyFrom (CStream *Source, size_t Count)
 Copies a specified number of bytes from one stream to another. More...
 
void WriteObject (const CSerializable *o)
 Writes an object to the stream. More...
 
CSerializablePtr ReadObject ()
 Reads an object from stream, its class determined at runtime, and returns a smart pointer to the object. More...
 
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. More...
 
CStreamoperator<< (const CSerializablePtr &pObj)
 Write an object to a stream in the binary MRPT format. More...
 
CStreamoperator<< (const CSerializable &obj)
 Write an object to a stream in the binary MRPT format. More...
 
CStreamoperator>> (CSerializablePtr &pObj)
 
CStreamoperator>> (CSerializable &obj)
 
virtual int printf (const char *fmt,...) MRPT_printf_format_check(2
 Writes a string to the stream in a textual form. More...
 
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. More...
 
void sendMessage (const utils::CMessage &msg)
 Send a message to the device. More...
 
bool receiveMessage (utils::CMessage &msg)
 Tries to receive a message from the device. More...
 
bool getline (std::string &out_str)
 Reads from the stream until a '
' character is found ('' characters are ignored). More...
 

Protected Member Functions

size_t Read (void *Buffer, size_t Count)
 Method responsible for reading from the stream. More...
 
size_t Write (const void *Buffer, size_t Count)
 Method responsible for writing to the stream. More...
 

Private Attributes

std::fstream m_f
 The actual input file stream. More...
 

Member Enumeration Documentation

◆ TSeekOrigin

Used in CStream::Seek.

Enumerator
sFromBeginning 
sFromCurrent 
sFromEnd 

Definition at line 41 of file CStream.h.

Constructor & Destructor Documentation

◆ CFileStream() [1/2]

mrpt::utils::CFileStream::CFileStream ( const std::string &  fileName,
TFileOpenModes  mode = fomRead|fomWrite 
)

Constructor and open a file.

Parameters
fileNameThe file to be open in this stream
modeThe open mode: can be an or'd conbination of different values.
Exceptions
std::exceptionOn error creating or accessing the file. By default the file is opened for open and write and created if not found.

◆ CFileStream() [2/2]

mrpt::utils::CFileStream::CFileStream ( )

Constructor.

◆ ~CFileStream()

virtual mrpt::utils::CFileStream::~CFileStream ( )
virtual

Destructor.

Member Function Documentation

◆ checkEOF()

bool mrpt::utils::CFileStream::checkEOF ( )

Will be true if EOF has been already reached.

◆ close()

void mrpt::utils::CFileStream::close ( )

Closes the file.

◆ CopyFrom()

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

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

◆ fileOpenCorrectly()

bool mrpt::utils::CFileStream::fileOpenCorrectly ( )

Says if file was open successfully or not.

◆ getline()

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.

◆ getPosition()

uint64_t mrpt::utils::CFileStream::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.

◆ getPositionI()

uint64_t mrpt::utils::CFileStream::getPositionI ( )

The current Input cursor position, where 0 is the first byte.

◆ getPositionO()

uint64_t mrpt::utils::CFileStream::getPositionO ( )

The current Input cursor position, where 0 is the first byte.

◆ getTotalBytesCount()

uint64_t mrpt::utils::CFileStream::getTotalBytesCount ( )
virtual

Method for getting the total number of bytes writen to buffer.

Implements mrpt::utils::CStream.

◆ open()

bool mrpt::utils::CFileStream::open ( const std::string &  fileName,
TFileOpenModes  mode = fomRead|fomWrite 
)

Opens the file, returning true on success.

Parameters
fileNameThe file to be open in this stream
modeThe open mode: can be an or'd conbination of different values. By default the file is opened for open and write and created if not found.

◆ operator<<() [1/2]

CStream& mrpt::utils::CStream::operator<< ( const CSerializablePtr pObj)
inherited

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

◆ operator<<() [2/2]

CStream& mrpt::utils::CStream::operator<< ( const CSerializable obj)
inherited

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

◆ operator>>() [1/2]

CStream& mrpt::utils::CStream::operator>> ( CSerializablePtr pObj)
inherited

◆ operator>>() [2/2]

CStream& mrpt::utils::CStream::operator>> ( CSerializable obj)
inherited

◆ printf()

virtual int mrpt::utils::CStream::printf ( const char *  fmt,
  ... 
)
virtualinherited

◆ printf_vector()

template<typename T >
virtual int void mrpt::utils::CStream::printf_vector ( const char *  fmt,
const std::vector< T > &  V 
)
inlineinherited

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

Definition at line 200 of file CStream.h.

◆ Read()

size_t mrpt::utils::CFileStream::Read ( void *  Buffer,
size_t  Count 
)
protectedvirtual

Method responsible for reading from the stream.

Implements mrpt::utils::CStream.

◆ ReadBuffer()

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

Reads a block of bytes from the stream into Buffer.

Exceptions
std::exceptionOn 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,

◆ ReadBufferFixEndianness()

template<typename T >
size_t mrpt::utils::CStream::ReadBufferFixEndianness ( T *  ptr,
size_t  ElementCount 
)
inlineinherited

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
ElementCountThe number of elements (not bytes) to read.
ptrA 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::exceptionOn any error, or if ZERO bytes are read.
See also
ReadBufferFixEndianness, ReadBuffer

Definition at line 90 of file CStream.h.

References mrpt::mrpt::utils::reverseBytesInPlace().

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

◆ ReadBufferImmediate()

virtual size_t mrpt::utils::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::exceptionOn any error, or if ZERO bytes are read.

Reimplemented in mrpt::hwdrivers::CInterfaceFTDI.

Definition at line 108 of file CStream.h.

◆ readLine()

bool mrpt::utils::CFileStream::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.

◆ ReadObject() [1/2]

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::exceptionOn I/O error or undefined class.
mrpt::utils::CExceptionEOFOn 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>>().

◆ ReadObject() [2/2]

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::exceptionOn I/O error or different class found.
mrpt::utils::CExceptionEOFOn 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.

◆ receiveMessage()

bool mrpt::utils::CStream::receiveMessage ( utils::CMessage msg)
inherited

Tries to receive a message from the device.

Exceptions
std::exceptionOn 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()

◆ Seek()

uint64_t mrpt::utils::CFileStream::Seek ( uint64_t  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.

◆ sendMessage()

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::exceptionOn communication errors

◆ Write()

size_t mrpt::utils::CFileStream::Write ( const void *  Buffer,
size_t  Count 
)
protectedvirtual

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.

◆ WriteBuffer()

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

Writes a block of bytes to the stream from Buffer.

Exceptions
std::exceptionOn any error
See also
Important, see: WriteBufferFixEndianness
Note
This method is endianness-dependent.

◆ WriteBufferFixEndianness()

template<typename T >
void mrpt::utils::CStream::WriteBufferFixEndianness ( const T *  ptr,
size_t  ElementCount 
)
inlineinherited

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

Parameters
ElementCountThe number of elements (not bytes) to write.
ptrA 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::exceptionOn any error
See also
WriteBuffer

Definition at line 134 of file CStream.h.

◆ WriteObject()

void mrpt::utils::CStream::WriteObject ( const CSerializable o)
inherited

Writes an object to the stream.

Member Data Documentation

◆ m_f

std::fstream mrpt::utils::CFileStream::m_f
private

The actual input file stream.

Definition at line 55 of file CFileStream.h.




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