mfile.h

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/* 
 *      HT Editor
 *      mfile.h
 *
 *      Copyright (C) 1999-2002 Stefan Weyergraf (stefan@weyergraf.de)
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License version 2 as
 *      published by the Free Software Foundation.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __MFILE_H__
#define __MFILE_H__

#include "htdata.h"
#include "stream.h"

typedef FILEOFS PAGEOFS;

/*
 *      CLASS ht_mod_page
 */

#define DEFAULT_MOD_PAGE_SIZE 8*1024    /* MUST BE 2^n */

class ht_mod_page: public Object {
public:
        UINT size;
        byte *data;

                        ht_mod_page(UINT size);
                        ~ht_mod_page();
/* new */
        virtual UINT    read(PAGEOFS pofs, byte *buf, UINT len);
        virtual UINT    write(PAGEOFS pofs, const byte *buf, UINT len);
};

/*
 *      CLASS ht_streamfile_modifier
 */

class ht_streamfile_modifier: public ht_layer_streamfile {
protected:
        ht_tree *mod_pages;

        bool modified;

        FILEOFS offset;
        UINT size;

        UINT page_granularity;
        UINT page_mask;

        bool active;
/* new */
        virtual void    mod_pages_create();
        virtual void    mod_pages_destroy();

                   void mod_pages_flush();
                   void mod_pages_invd();
                         
        virtual ht_mod_page *mod_page_create(FILEOFS offset);
        virtual void    mod_page_destroy(FILEOFS offset);
        virtual ht_mod_page *mod_page_find(FILEOFS offset);
        virtual void    mod_page_flush(FILEOFS offset);

                   void cleardirtybyte(FILEOFS offset);
                   
                   bool isdirty(FILEOFS offset, UINT range);

                   bool isdirtybit(FILEOFS offset, UINT bit);
                   bool isdirtybyte(FILEOFS offset);
                   bool readbyte(FILEOFS offset, byte *b);
                   bool writebyte(FILEOFS offset, byte b);
public:
                   void init(ht_streamfile *streamfile, int own_streamfile, UINT page_granularity = DEFAULT_MOD_PAGE_SIZE);
        virtual void    done();
/* overwritten */
        virtual int     extend(UINT newsize);
        virtual UINT    get_size();
        virtual UINT    read(void *buf, UINT size);
        virtual int     seek(FILEOFS offset);
        virtual bool    set_access_mode(UINT access_mode);
        virtual FILEOFS tell();
        virtual int     truncate(UINT newsize);
        virtual int     vcntl(UINT cmd, va_list vargs);
        virtual UINT    write(const void *buf, UINT size);
};

#endif /* __MFILE_H__ */

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