CFileStream.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef  CFILESTREAM_H
#define  CFILESTREAM_H

#include <mrpt/utils/CStream.h>
#include <mrpt/utils/CUncopiable.h>

#include <fstream>

namespace mrpt
{
        namespace utils
        {
                /** File open modes are used in CFileStream
                  *  Posible values are:
                        - fomRead
                        - fomWrite (creates the file if it didn't exist, otherwise truncates it).
                        - fomAppend (creates the file if it didn't exist)
                  */
                typedef int TFileOpenModes;
                enum {
                        fomRead   = 1,
                        fomWrite  = 2,
                        fomAppend = 4
                };

                /** 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.
                 * \sa CStream, CFileInputStream, CFileOutputStrea, CFileGZInputStream
                 * \ingroup mrpt_base_grp
                 */
                class BASE_IMPEXP  CFileStream : public CStream, public CUncopiable
                {
                protected:
                        size_t  Read(void *Buffer, size_t Count) MRPT_OVERRIDE;
                        size_t  Write(const void *Buffer, size_t Count) MRPT_OVERRIDE;
                private:
                        std::fstream    m_f;            //!< The actual input file stream.
                public:
                         /** Constructor and open a file
                          * \param fileName The file to be open in this stream
                          * \param mode The open mode: can be an or'd conbination of different values.
                          * \exception std::exception On error creating or accessing the file.
                          *  By default the file is opened for open and write and created if not found.
                          */
                        CFileStream( const std::string &fileName, TFileOpenModes mode = fomRead | fomWrite);
                        /** Constructor */
                        CFileStream();
                        virtual ~CFileStream(); //!< Destructor

                        /** Opens the file, returning true on success.
                          * \param fileName The file to be open in this stream
                          * \param mode The 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.
                          */
                        bool open(const std::string &fileName, TFileOpenModes mode = fomRead | fomWrite );
                        void close(); //!< Closes the file
                        bool fileOpenCorrectly(); //!< Returns true if the file was open without errors.
                        bool is_open() { return fileOpenCorrectly(); } //!< Returns true if the file was open without errors.
                        bool checkEOF(); //!< Will be true if EOF has been already reached.
                        void clearError(); //!< Resets stream error status bits (e.g. after an EOF)

                        /** Method for moving to a specified position in the streamed resource.
                         *   See documentation of CStream::Seek
                         */
                        uint64_t Seek(int64_t Offset, CStream::TSeekOrigin Origin = sFromBeginning) MRPT_OVERRIDE;

                        uint64_t getTotalBytesCount() MRPT_OVERRIDE; //!< Method for getting the total number of bytes writen to buffer.
                        uint64_t getPosition() MRPT_OVERRIDE; //!< Method for getting the current cursor position, where 0 is the first byte and TotalBytesCount-1 the last one
                        uint64_t getPositionI(); //!< The current Input cursor position, where 0 is the first byte
                        uint64_t getPositionO(); //!< The current Input cursor position, where 0 is the first byte

                        /** Reads one string line from the file (until a new-line character)
                          * \return true if a line has been read, false on EOF or error */
                        bool readLine( std::string &str );

                }; // End of class def.

        } // End of namespace
} // end of namespace
#endif