fatfs.h

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/*
 * Copyright 2004 Martin Fuchs
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */


 //
 // Explorer clone
 //
 // fatfs.h
 //
 // Martin Fuchs, 01.02.2004
 //


struct FATEntry : public Entry
{
    FATEntry(Entry* parent, unsigned cluster) : Entry(parent, ET_FAT), _cluster(cluster) {}

protected:
    FATEntry() : Entry(ET_FAT) {}

    virtual bool get_path(PTSTR path, size_t path_count) const;
    virtual ShellPath create_absolute_pidl() const;

    DWORD   _cluster;
};


struct FATDrive;

struct FATDirectory : public FATEntry, public Directory
{
    FATDirectory(FATDrive& drive, LPCTSTR root_path);
    FATDirectory(FATDrive& drive, Entry* parent, LPCTSTR path, unsigned cluster);
    ~FATDirectory();

    virtual void read_directory(int scan_flags=0);
    virtual const void* get_next_path_component(const void*) const;
    virtual Entry* find_entry(const void*);

protected:
    FATDrive&   _drive;

    struct dirsecz* _secarr;
    int     _cur_bufs;
    int     _ents;
    struct dirent* _dir;
    struct Kette* _alloc;

    bool    read_dir();
};


#pragma pack(push, 1)

struct BootSector {
    BYTE    jmp[3];
    char    OEM[8];
    WORD    BytesPerSector;     // dpb.bsec
    BYTE    SectorsPerCluster;  // dpb.sclus + 1
    WORD    ReservedSectors;    // dpb.ffatsec
    BYTE    NumberFATs;
    WORD    RootEntries;        // dpb.ndir
    WORD    Sectors16;
    BYTE    MediaDescr;
    WORD    SectorsPerFAT;
    WORD    SectorsPerTrack;
    WORD    Heads;
    DWORD   HiddenSectors;
    DWORD   Sectors32;
    BYTE    DriveUnit;
    WORD    ExtBootFlag;
    DWORD   SerialNr;
    char    Label[11];
    char    FileSystem[8];
    BYTE    BootCode[448];
    BYTE    BootSignature[2];
};

struct BootSector32 {
    BYTE    jmp[3];
    char    OEM[8];
    WORD    BytesPerSector;
    BYTE    SectorsPerCluster;
    WORD    ReservedSectors;
    BYTE    NumberFATs;
    WORD    reserved1;  // immer 0 für FAT32
    WORD    Sectors16;
    BYTE    MediaDescr;
    WORD    reserved2;  // immer 0 für FAT32
    WORD    SectorsPerTrack;
    WORD    Heads;
    DWORD   HiddenSectors;
    DWORD   Sectors32;
    DWORD   SectorsPerFAT32;
    DWORD   unknown1;
    DWORD   RootSectors; // correct?
    char    unknown2[6];
    char    FileSystem[8];
    BYTE    BootCode[448];
    BYTE    BootSignature[2];
};


struct filetime {
    WORD    sec2    : 5;
    WORD    min     : 6;
    WORD    hour    : 5;
};

struct filedate {
    WORD    day     : 5;
    WORD    month   : 4;
    WORD    year    : 7;
};

typedef struct {
    unsigned readonly   : 1;
    unsigned hidden     : 1;
    unsigned system     : 1;
    unsigned volume     : 1;
    unsigned directory  : 1;
    unsigned archived   : 1;
    unsigned deleted    : 1;
} fattr;

typedef union {
    char    b;
    fattr  a;
} FAT_attribute;

struct DEntry_E {
    char            name[8];
    char            ext[3];
    char            attr;
    char            rsrvd[10];
    struct filetime time;
    struct filedate date;
    WORD            fclus;
    DWORD           size;
};

union DEntry {
    DEntry_E E;
    BYTE B[8+3+1+10+sizeof(struct filetime)+sizeof(struct filedate)+sizeof(WORD)+sizeof(DWORD)];
};

#pragma pack(pop)


#define BufLen  512

struct Buffer {
 BYTE   dat[BufLen];
};

struct Cache {
 BYTE   dat[BufLen];
};

struct dskrwblk {
 DWORD          sec;
 WORD           anz;
 struct buffer  far *buf;
};

#define RONLY           0x01
#define HIDDEN          0x02
#define SYSTEM          0x04
#define VOLUME          0x08
#define DIRENT          0x10
#define ARCHIVE         0x20

#define _A_DELETED      0x40
#define _A_ILLEGAL      0x80
#define IS_LNAME(a) ((a&0xFF)==0x0F)    // "& 0xFF" correct?

#define FAT_DEL_CHAR    (char)0xe5

#define AddP(p,s)  {(int&)p += s;}

struct dirent {
    union DEntry  ent[1];
};

struct dirsecz {
    DWORD  s[32];  // 32 only as placeholder
};

struct Kette {
 struct Kette*  Vorw;
 struct Kette*  Rueck;
 union DEntry*  Ent;
};


#define MK_P(ofs)       ((void*) ((size_t)(ofs)))
#define MK_LONG(l,h)    ((DWORD)WORD(l)|((DWORD)WORD(h)<<16))

#define spoke(ofs,w)    (*((BYTE*)MK_P(ofs)) = (BYTE)(w))
#define wpoke(ofs,w)    (*((WORD*)MK_P(ofs)) = (WORD)(w))
#define dpoke(ofs,w)    (*((DWORD*)MK_P(ofs)) = (DWORD)(w))
#define speek(ofs)      (*((BYTE*)MK_P(ofs)))
#define wpeek(ofs)      (*((WORD*)MK_P(ofs)))
#define dpeek(p)        (*((DWORD*)MK_P(p)))


struct FATDrive : public FATDirectory
{
    FATDrive(LPCTSTR path);
/*
    FATDrive(Entry* parent, LPCTSTR path)
     :  FATEntry(parent)
    {
        _path = _tcsdup(path);
    }
*/
    ~FATDrive();

    HANDLE  _hDrive;
    BootSector  _boot_sector;
    int     _bufl;
    int     _bufents;
    int     _SClus;

#define CACHE_SIZE_LOW  32
    Cache*  _FATCache;
    int     _CacheCount;
    DWORD*  _CacheSec;  // numbers of buffered cache sectors
    int*    _CacheCnt;  // counters for cache usage
    bool*   _CacheDty;  // dirty flags for cache
    int     _Caches;
    bool    _cache_empty;
    int     _read_ahead;

    bool    read_sector(DWORD sec, Buffer* buf, int len);
    DWORD   read_FAT(DWORD Clus, bool& ok);

    void    small_cache();
    void    reset_cache();
    bool    read_cache(DWORD sec, Buffer** bufptr);
    int     get_cache_buffer();
};