root/src/mysql/raid.h @ 23

/* Copyright (C) 2000 MySQL AB

   This program 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 of the License, or
   (at your option) any later version.

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* Parser needs these defines  always, even if USE_RAID is not defined */
#define RAID_TYPE_0 1       /* Striping */
#define RAID_TYPE_x 2       /* Some new modes */
#define RAID_TYPE_y 3

#define RAID_DEFAULT_CHUNKS 4
#define RAID_DEFAULT_CHUNKSIZE 256*1024 /* 256kB */

C_MODE_START
#define my_raid_type(raid_type)  raid_type_string[(int)(raid_type)]
extern const char *raid_type_string[];
C_MODE_END

#ifdef DONT_USE_RAID
#undef USE_RAID
#endif
#if defined(USE_RAID)

#include "my_dir.h"

/* Trap all occurences of my_...() in source and use our wrapper around this function */

#ifdef MAP_TO_USE_RAID
#define my_read(A,B,C,D)     my_raid_read(A,B,C,D)
#define my_write(A,B,C,D)    my_raid_write(A,B,C,D)
#define my_pwrite(A,B,C,D,E) my_raid_pwrite(A,B,C,D,E)
#define my_pread(A,B,C,D,E)  my_raid_pread(A,B,C,D,E)
#define my_chsize(A,B,C,D)   my_raid_chsize(A,B,C,D)
#define my_close(A,B)        my_raid_close(A,B)
#define my_tell(A,B)         my_raid_tell(A,B)
#define my_seek(A,B,C,D)     my_raid_seek(A,B,C,D)
#define my_lock(A,B,C,D,E)     my_raid_lock(A,B,C,D,E)
#define my_fstat(A,B,C)     my_raid_fstat(A,B,C)
#endif /* MAP_TO_USE_RAID */

#ifdef __cplusplus
extern "C" {
#endif

  void init_raid(void);
  void end_raid(void);

  bool is_raid(File fd);
  File my_raid_create(const char *FileName, int CreateFlags, int access_flags,
                      uint raid_type, uint raid_chunks, ulong raid_chunksize,
                      myf MyFlags);
  File my_raid_open(const char *FileName, int Flags,
                    uint raid_type, uint raid_chunks, ulong raid_chunksize,
                    myf MyFlags);
  int my_raid_rename(const char *from, const char *to, uint raid_chunks,
                     myf MyFlags);
  int my_raid_delete(const char *from, uint raid_chunks, myf MyFlags);
  int my_raid_redel(const char *old_name, const char *new_name,
                    uint raid_chunks, myf MyFlags);

  my_off_t my_raid_seek(File fd, my_off_t pos, int whence, myf MyFlags);
  my_off_t my_raid_tell(File fd, myf MyFlags);

  uint my_raid_write(File,const byte *Buffer, uint Count, myf MyFlags);
  uint my_raid_read(File Filedes, byte *Buffer, uint Count, myf MyFlags);

  uint my_raid_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset,
                     myf MyFlags);
  uint my_raid_pwrite(int Filedes, const byte *Buffer, uint Count,
                      my_off_t offset, myf MyFlags);

  int my_raid_lock(File,int locktype, my_off_t start, my_off_t length,
                   myf MyFlags);
  int my_raid_chsize(File fd, my_off_t newlength, int filler, myf MyFlags);
  int my_raid_close(File, myf MyFlags);
  int my_raid_fstat(int Filedes, struct stat *buf,  myf MyFlags);

#ifdef __cplusplus
}

#ifdef USE_PRAGMA_INTERFACE
#pragma interface                       /* gcc class implementation */
#endif

class RaidName {
  public:
    RaidName(const char *FileName);
    ~RaidName();
    bool IsRaid();
    int Rename(const char * from, const char * to, myf MyFlags);
  private:
    uint _raid_type;       /* RAID_TYPE_0 or RAID_TYPE_1 or RAID_TYPE_5 */
    uint _raid_chunks;     /* 1..n */
    ulong _raid_chunksize; /* 1..n in bytes */
};

class RaidFd {
  public:
    RaidFd(uint raid_type, uint raid_chunks , ulong raid_chunksize);
    ~RaidFd();
    File Create(const char *FileName, int CreateFlags, int access_flags,
                myf MyFlags);
    File Open(const char *FileName, int Flags, myf MyFlags);
    my_off_t Seek(my_off_t pos,int whence,myf MyFlags);
    my_off_t Tell(myf MyFlags);
    int Write(const byte *Buffer, uint Count, myf MyFlags);
    int Read(const byte *Buffer, uint Count, myf MyFlags);
    int Lock(int locktype, my_off_t start, my_off_t length, myf MyFlags);
    int Chsize(File fd, my_off_t newlength, int filler, myf MyFlags);
    int Fstat(int fd, MY_STAT *stat_area, myf MyFlags );
    int Close(myf MyFlags);
    static bool IsRaid(File fd);
    static DYNAMIC_ARRAY _raid_map;             /* Map of RaidFD* */
  private:

    uint _raid_type;       /* RAID_TYPE_0 or RAID_TYPE_1 or RAID_TYPE_5 */
    uint _raid_chunks;     /* 1..n */
    ulong _raid_chunksize; /* 1..n in bytes */

    ulong _total_block;    /* We are operating with block no x (can be 0..many). */
    uint _this_block;      /* can be 0.._raid_chunks */
    uint _remaining_bytes; /* Maximum bytes that can be written in this block */

    my_off_t _position;
    my_off_t _size;        /* Cached file size for faster seek(SEEK_END) */
    File _fd;
    File *_fd_vector;           /* Array of File */
    off_t *_seek_vector;        /* Array of cached seek positions */

    inline void Calculate()
    {
      DBUG_ENTER("RaidFd::_Calculate");
      DBUG_PRINT("info",("_position: %lu _raid_chunksize: %d, _size: %lu",
                         (ulong) _position, _raid_chunksize, (ulong) _size));

      _total_block = (ulong) (_position / _raid_chunksize);
      _this_block = _total_block % _raid_chunks;    /* can be 0.._raid_chunks */
      _remaining_bytes = (uint) (_raid_chunksize -
                                 (_position - _total_block * _raid_chunksize));
      DBUG_PRINT("info",
                 ("_total_block: %d  this_block: %d  _remaining_bytes:%d",
                  _total_block, _this_block, _remaining_bytes));
      DBUG_VOID_RETURN;
    }
};

#endif /* __cplusplus */
#endif /* USE_RAID */