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mrpt::utils::CFileGZInputStream Class Reference
[mrpt-base]

Detailed Description

Transparently opens a compressed "gz" file and reads uncompressed data from it.

If the file is not a .gz file, it silently reads data from the file. This class requires compiling MRPT with wxWidgets. If wxWidgets is not available then the class is actually mapped to the standard CFileInputStream

See also:
CFileInputStream

#include <mrpt/utils/CFileGZInputStream.h>

Inheritance diagram for mrpt::utils::CFileGZInputStream:
Inheritance graph
[legend]

List of all members.

Public Types

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

Public Member Functions

 CFileGZInputStream ()
 Constructor without open.
 CFileGZInputStream (const std::string &fileName)
 Constructor and open.
virtual ~CFileGZInputStream ()
 Destructor.
bool open (const std::string &fileName)
 Opens the file for read.
void close ()
 Closes the file.
bool fileOpenCorrectly ()
 Says if file was open successfully or not.
bool checkEOF ()
 Will be true if EOF has been already reached.
uint64_t getTotalBytesCount ()
 Method for getting the total number of compressed bytes of in the file (the physical size of the compressed file).
uint64_t getPosition ()
 Method for getting the current cursor position in the compressed, where 0 is the first byte and TotalBytesCount-1 the last one.
uint64_t Seek (long Offset, CStream::TSeekOrigin Origin=sFromBeginning)
 This method is not implemented in this class.
size_t ReadBuffer (void *Buffer, size_t Count)
 Reads a block of bytes from the stream into Buffer

Exceptions:
std::exceptionOn 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

void * m_f
uint64_t m_file_size
 Compressed file size.

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.

Constructor & Destructor Documentation

mrpt::utils::CFileGZInputStream::CFileGZInputStream ( )

Constructor without open.

mrpt::utils::CFileGZInputStream::CFileGZInputStream ( const std::string &  fileName)

Constructor and open.

Parameters:
fileNameThe file to be open in this stream
Exceptions:
std::exceptionIf there's an error opening the file.
virtual mrpt::utils::CFileGZInputStream::~CFileGZInputStream ( ) [virtual]

Destructor.

Member Function Documentation

bool mrpt::utils::CFileGZInputStream::checkEOF ( )

Will be true if EOF has been already reached.

void mrpt::utils::CFileGZInputStream::close ( )

Closes the file.

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::CFileGZInputStream::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::CFileGZInputStream::getPosition ( ) [virtual]

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

Implements mrpt::utils::CStream.

uint64_t mrpt::utils::CFileGZInputStream::getTotalBytesCount ( ) [virtual]

Method for getting the total number of compressed bytes of in the file (the physical size of the compressed file).

Implements mrpt::utils::CStream.

bool mrpt::utils::CFileGZInputStream::open ( const std::string &  fileName)

Opens the file for read.

Parameters:
fileNameThe file to be open in this stream
Returns:
false if there's an error opening the file, true otherwise
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::CFileGZInputStream::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::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,
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:
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 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::exceptionOn any error, or if ZERO bytes are read.

Reimplemented in mrpt::hwdrivers::CInterfaceFTDI.

Definition at line 127 of file CStream.h.

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>>().

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

This method is not implemented in this class.

Implements mrpt::utils::CStream.

Definition at line 109 of file CFileGZInputStream.h.

References THROW_EXCEPTION.

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
size_t mrpt::utils::CFileGZInputStream::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::exceptionOn 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:
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 153 of file CStream.h.

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

Writes an object to the stream.

Member Data Documentation

void* mrpt::utils::CFileGZInputStream::m_f [private]

Definition at line 65 of file CFileGZInputStream.h.

uint64_t mrpt::utils::CFileGZInputStream::m_file_size [private]

Compressed file size.

Definition at line 66 of file CFileGZInputStream.h.



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