kernel/hdr/buffer.h

63 lines
3.2 KiB
C

/****************************************************************/
/* */
/* buffer.h */
/* */
/* Sector buffer structure */
/* */
/* Copyright (c) 2001 */
/* Bart Oldeman */
/* */
/* Largely taken from globals.h: */
/* Copyright (c) 1995, 1996 */
/* Pasquale J. Villani */
/* All Rights Reserved */
/* */
/* This file is part of DOS-C. */
/* */
/* DOS-C 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. */
/* */
/* DOS-C 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 DOS-C; see the file COPYING. If not, */
/* write to the Free Software Foundation, 675 Mass Ave, */
/* Cambridge, MA 02139, USA. */
/****************************************************************/
#ifdef MAIN
#ifdef VERSION_STRINGS
static BYTE *buffer_hRcsId =
"$Id$";
#endif
#endif
#define BUFFERSIZE 512
struct buffer {
UWORD b_next; /* next buffer in LRU list */
UWORD b_prev; /* previous buffer in LRU list */
BYTE b_unit; /* disk for this buffer */
BYTE b_flag; /* buffer flags */
ULONG b_blkno; /* block for this buffer */
UBYTE b_copies; /* number of copies to write */
UWORD b_offset; /* offset in sectors between copies
to write for FAT sectors */
struct dpb FAR *b_dpbp; /* pointer to DPB */
UWORD b_remotesz; /* size of remote buffer if remote */
BYTE b_padding;
UBYTE b_buffer[BUFFERSIZE]; /* 512 byte sectors for now */
};
#define BFR_DIRTY 0x40 /* buffer modified */
#define BFR_VALID 0x20 /* buffer contains valid data */
#define BFR_DATA 0x08 /* buffer is from data area */
#define BFR_DIR 0x04 /* buffer is from dir area */
#define BFR_FAT 0x02 /* buffer is from fat area */
#define BFR_UNCACHE 0x01 /* buffer to be released ASAP */