BufferedFileClass.h

/*  Renegade Scripts.dll
    Copyright 2013 Tiberian Technologies
 
    This file is part of the Renegade scripts.dll
    The Renegade scripts.dll is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License as published by the Free
    Software Foundation; either version 2, or (at your option) any later
    version. See the file COPYING for more details.
    In addition, an exemption is given to allow Run Time Dynamic Linking of this code with any closed source module that does not contain code covered by this licence.
    Only the source code to the module(s) containing the licenced code has to be released.
*/
#ifndef TT_INCLUDE_BUFFEREDFILECLASS_H
#define TT_INCLUDE_BUFFEREDFILECLASS_H
 
#include "RawFileClass.h"
class BufferedFileClass : public RawFileClass {
private:
    unsigned char* Buffer;
    unsigned int BufferSize;
    int BufferAvailable;
    int BufferOffset;
public:
    BufferedFileClass() : Buffer(0), BufferSize(0), BufferAvailable(0), BufferOffset(0)
    {
    }
    ~BufferedFileClass()
    {
        Reset_Buffer();
    }
    int Read(void* buffer,int size)
    {
        void *tmp = buffer;
        int sz = size;
        int result = 0;
        if (BufferAvailable > 0)
        {
            int buf = BufferAvailable;
            if (buf > size)
            {
                buf = size;
            }
            memcpy(buffer, Buffer + BufferOffset, buf);
            BufferAvailable -= buf;
            BufferOffset += buf;
            sz -= buf;
            tmp = (char *)tmp + buf;
            result += buf;
        }
        if (sz)
        {
            int buf = BufferSize;
            if (!buf)
            {
                buf = 16384;
            }
            if (sz > buf)
            {
                return result + RawFileClass::Read(tmp,sz);
            }
            if (!BufferSize)
            {
                BufferSize = 16384;
                Buffer = new unsigned char[16384];
                BufferAvailable = 0;
                BufferOffset = 0;
            }
            if (!Buffer)
            {
                return 0;
            }
            if (!BufferAvailable)
            {
                BufferAvailable = RawFileClass::Read(Buffer,BufferSize);
                BufferOffset = 0;
            }
            if (BufferAvailable > 0)
            {
                int buf2 = BufferAvailable;
                if (buf2 > sz)
                {
                    buf2 = sz;
                }
                if (!Buffer)
                {
                    return 0;
                }
                memcpy(tmp,Buffer+BufferOffset,buf2);
                BufferAvailable -= buf2;
                BufferOffset += buf2;
                result += buf2;
            }
        }
        return result;
    }
    int Seek(int pos,int dir)
    {
        if (dir != 1 || pos < 0)
        {
            Reset_Buffer();
        }
        if (BufferAvailable)
        {
            int buf = BufferAvailable;
            if (buf > pos)
            {
                buf = pos;
            }
            BufferAvailable -= buf;
            BufferOffset += buf;
            return RawFileClass::Seek(pos - buf,dir) - BufferAvailable;
        }
        else
        {
            return RawFileClass::Seek(pos,dir);
        }
    }
    int Write(void* buffer,int size)
    {
        return RawFileClass::Write(buffer,size);
    }
    void Close()
    {
        RawFileClass::Close();
        Reset_Buffer();
    }
    void Reset_Buffer()
    {
        if (Buffer)
        {
            delete[] Buffer;
            Buffer = 0;
            BufferSize = 0;
            BufferAvailable = 0;
            BufferOffset = 0;
        }
    }
};
 
#endif