CFileGZInputStream.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 CFileGZInputStream_H
#define CFileGZInputStream_H

#include <mrpt/utils/CStream.h>

namespace mrpt
{
namespace utils
{
/** 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
 *
 * \sa CFileInputStream
 * \ingroup mrpt_base_grp
 */
class CFileGZInputStream : public CStream
{
   protected:
        size_t Read(void* Buffer, size_t Count) override;
        size_t Write(const void* Buffer, size_t Count) override;

   private:
        void* m_f;
        /** Compressed file size */
        uint64_t m_file_size;

   public:
        /** Constructor without open */
        CFileGZInputStream();

        /** Constructor and open
         * \param fileName The file to be open in this stream
         * \exception std::exception If there's an error opening the file.
         */
        CFileGZInputStream(const std::string& fileName);

        CFileGZInputStream(const CFileGZInputStream&) = delete;
        CFileGZInputStream& operator=(const CFileGZInputStream&) = delete;

        /** Dtor */
        virtual ~CFileGZInputStream();

        /** Opens the file for read.
         * \param fileName The file to be open in this stream
         * \return false if there's an error opening the file, true otherwise
         */
        bool open(const std::string& fileName);
        /** Closes the file */
        void close();
        /** Returns true if the file was open without errors. */
        bool fileOpenCorrectly();
        /** Returns true if the file was open without errors. */
        bool is_open() { return fileOpenCorrectly(); }
        /** Will be true if EOF has been already reached. */
        bool checkEOF();

        /** Method for getting the total number of <b>compressed</b> bytes of in the
         * file (the physical size of the compressed file). */
        uint64_t getTotalBytesCount() override;
        /** Method for getting the current cursor position in the <b>compressed</b>,
         * where 0 is the first byte and TotalBytesCount-1 the last one. */
        uint64_t getPosition() override;

        /** This method is not implemented in this class */
        uint64_t Seek(
                uint64_t Offset, CStream::TSeekOrigin Origin = sFromBeginning) override
        {
                MRPT_UNUSED_PARAM(Offset);
                MRPT_UNUSED_PARAM(Origin);
                THROW_EXCEPTION("Seek is not implemented in this class");
        }

};  // End of class def.

static_assert(
        !std::is_copy_constructible<CFileGZInputStream>::value &&
                !std::is_copy_assignable<CFileGZInputStream>::value,
        "Copy Check");
}  // End of namespace
}  // end of namespace
#endif