rockbox/firmware/include/fs_defines.h
Michael Sevakis 6db80020b4 Do some housekeeping with fat.h and SECTOR_SIZE
Many includes of fat.h are pointless. Some includes are just for
SECTOR_SIZE. Add a file 'firmware/include/fs_defines.h' for that
and to define tuneable values that were scattered amongst various
headers.

Remove some local definitions of SECTOR_SIZE since they have to be
in agreement with the rest of the fs code anyway.

(We'll see what's in fact pointless in a moment ;)

Change-Id: I9ba183bf58bd87f5c45eba7bd675c7e2c1c18ed5
2017-03-12 22:05:44 -04:00

108 lines
3.9 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2017 by Michael Sevakis
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef FS_DEFINES_H
#define FS_DEFINES_H
/** Tuneable parameters **/
#if 0
/* Define this just in case you're doing something that may crash a lot and
want less write caching */
#define FS_MIN_WRITECACHING
#endif
#ifndef MAX_PATH
#define MAX_PATH 260
#endif
#define MAX_COMPNAME 260
/* still experimental? */
/* increasing this will increase the total memory used by the cache; the
cache, as noted in disk_cache.h, has other minimum requirements that may
prevent reducing its number of entries in order to compensate */
#ifndef SECTOR_SIZE
#define SECTOR_SIZE 512
#endif
/* limits for number of open descriptors - if you increase these values, make
certain that the disk cache has enough available buffers */
#define MAX_OPEN_FILES 11
#define MAX_OPEN_DIRS 12
/* internal functions open streams as well; make sure they don't fail if all
user descs are busy; this needs to be at least the greatest quantity needed
at once by all internal functions */
#ifdef HAVE_DIRCACHE
#define AUX_FILEOBJS 3
#else
#define AUX_FILEOBJS 2
#endif
/* number of components statically allocated to handle the vast majority
of path depths; should maybe be tuned for >= 90th percentile but for now,
imma just guessing based on something like:
root + 'Music' + 'Artist' + 'Album' + 'Disc N' + filename */
#define STATIC_PATHCOMP_NUM 6
/* unsigned value that will also hold the off_t range we need without
overflow */
#define file_size_t uint32_t
#ifdef __USE_FILE_OFFSET64
/* if we want, we can deal with files up to 2^32-1 bytes-- the full FAT16/32
range */
#define FILE_SIZE_MAX (0xffffffffu)
#else
/* file contents and size will be preserved by the APIs so long as ftruncate()
isn't used; bytes passed 2^31-1 will not accessible nor will writes succeed
that would extend the file beyond the max for a 32-bit off_t */
#define FILE_SIZE_MAX (0x7fffffffu)
#endif
/* if file is "large(ish)", then get rid of the contents now rather than
lazily when the file is synced or closed in order to free-up space */
#define O_TRUNC_THRESH 65536
/* This needs enough for all file handles to have a buffer in the worst case
* plus at least one reserved exclusively for the cache client and a couple
* for other file system code. The buffers are put to use by the cache if not
* taken for another purpose (meaning nothing is wasted sitting fallow).
*
* One map per volume is maintained in order to avoid collisions between
* volumes that would slow cache probing. IOC_MAP_NUM_ENTRIES is the number
* for each map per volume. The buffers themselves are shared.
*/
#if MEMORYSIZE < 8
#define DC_NUM_ENTRIES 32
#define DC_MAP_NUM_ENTRIES 128
#elif MEMORYSIZE <= 32
#define DC_NUM_ENTRIES 48
#define DC_MAP_NUM_ENTRIES 128
#else /* MEMORYSIZE > 32 */
#define DC_NUM_ENTRIES 64
#define DC_MAP_NUM_ENTRIES 256
#endif /* MEMORYSIZE */
/* this _could_ be larger than a sector if that would ever be useful */
#define DC_CACHE_BUFSIZE SECTOR_SIZE
#endif /* FS_DEFINES_H */