F:/My Projects/LSEngine/Modules/LSFileLib/Src/HighLevel/LSFFileMap.h

#ifndef __LSF_FILEMAP_H__
#define __LSF_FILEMAP_H__

#include "../LSFFileLib.h"

namespace lsf {

        class CFileMap {
        public :
                // == Various constructors.
                LSE_CALL                                CFileMap();
                LSE_CALL                                ~CFileMap();


                // == Functions.
                LSBOOL LSE_CALL                 CreateFileMap( const LSCHAR * _pcFile, LSF_OPEN_FILE _ofOpenType = LSF_OF_READ, LSUINT32 _ui32BufferSize = 0UL );

                LSBOOL LSE_CALL                 CreateFileMap( const LSWCHAR_T * _pwcFile, LSF_OPEN_FILE _ofOpenType = LSF_OF_READ, LSUINT32 _ui32BufferSize = 0UL );

                LSVOID LSE_CALL                 Reset();

                LSUINT32 LSE_CALL               ReadBytes( LSVOID * _pvBuffer, LSUINT64 _ui64Offset, LSUINT32 _ui32Total ) const;

                LSUINT32 LSE_CALL               WriteBytes( const LSUINT8 * _pui8Buffer, LSUINT64 _ui64Offset, LSUINT32 _ui32Total );

                LSUINT64 LSE_CALL               GetFileSize() const;

        protected :
                // == Members.
                // Our file map.
                LSF_FILE_MAP                    m_fmMap;

                // Have we mapped a file?
                LSBOOL                                  m_bMapped;

                // Address we have mapped.
                mutable LSVOID *                m_pvAddr;

                // Size of the mapping.
                LSUINTPTR                               m_uiptrSize;

                // Current size of the mapping.
                mutable LSUINTPTR               m_uiptrCurSize;

                // Size of the file.
                LSUINT64                                m_ui64FileSize;

                // Currently buffered offset.
                mutable LSUINT64                m_ui64Offset;


                // == Functions.
                LSUINT64 LSE_CALL               GetBaseOffset( LSUINT64 _ui64Offset ) const;

                LSUINT8 * LSE_CALL              GetBuffer( LSUINT64 _ui64Offset, LSUINT32 &_ui32MaxLen ) const;
        };


        // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
        // DEFINITIONS
        // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
        LSE_INLINE LSUINT64 LSE_CALL CFileMap::GetFileSize() const {
                return m_ui64FileSize;
        }

        LSE_INLINE LSUINT64 LSE_CALL CFileMap::GetBaseOffset( LSUINT64 _ui64Offset ) const {
                if ( _ui64Offset < (m_uiptrSize >> 1UL) ) { return 0UL; }
                if ( m_ui64FileSize <= m_uiptrSize ) { return 0UL; }
                return ((_ui64Offset + (m_uiptrSize >> 2UL)) & (~((m_uiptrSize >> 1UL) - 1UL))) - (m_uiptrSize >> 1UL);
        }

}       // namespace lsf

#endif  // __LSF_FILEMAP_H__