mirror of
https://github.com/ventoy/Ventoy.git
synced 2024-12-28 16:15:59 -05:00
92 lines
3.5 KiB
C
92 lines
3.5 KiB
C
|
//-----------------------------------------------------------------------------
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
// FAT16/32 File IO Library
|
||
|
|
// V2.6
|
||
|
|
// Ultra-Embedded.com
|
||
|
|
// Copyright 2003 - 2012
|
||
|
|
//
|
||
|
|
// Email: admin@ultra-embedded.com
|
||
|
|
//
|
||
|
|
// License: GPL
|
||
|
|
// If you would like a version with a more permissive license for use in
|
||
|
|
// closed source commercial applications please contact me for details.
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
//
|
||
|
|
// This file is part of FAT File IO Library.
|
||
|
|
//
|
||
|
|
// FAT File IO Library 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.
|
||
|
|
//
|
||
|
|
// FAT File IO 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 General Public License for more details.
|
||
|
|
//
|
||
|
|
// You should have received a copy of the GNU General Public License
|
||
|
|
// along with FAT File IO Library; if not, write to the Free Software
|
||
|
|
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
#include <string.h>
|
||
|
|
#include "fat_cache.h"
|
||
|
|
|
||
|
|
// Per file cluster chain caching used to improve performance.
|
||
|
|
// This does not have to be enabled for architectures with low
|
||
|
|
// memory space.
|
||
|
|
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
// fatfs_cache_init:
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
int fatfs_cache_init(struct fatfs *fs, FL_FILE *file)
|
||
|
|
{
|
||
|
|
#ifdef FAT_CLUSTER_CACHE_ENTRIES
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i=0;i<FAT_CLUSTER_CACHE_ENTRIES;i++)
|
||
|
|
{
|
||
|
|
file->cluster_cache_idx[i] = 0xFFFFFFFF; // Not used
|
||
|
|
file->cluster_cache_data[i] = 0;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
// fatfs_cache_get_next_cluster:
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
int fatfs_cache_get_next_cluster(struct fatfs *fs, FL_FILE *file, uint32 clusterIdx, uint32 *pNextCluster)
|
||
|
|
{
|
||
|
|
#ifdef FAT_CLUSTER_CACHE_ENTRIES
|
||
|
|
uint32 slot = clusterIdx % FAT_CLUSTER_CACHE_ENTRIES;
|
||
|
|
|
||
|
|
if (file->cluster_cache_idx[slot] == clusterIdx)
|
||
|
|
{
|
||
|
|
*pNextCluster = file->cluster_cache_data[slot];
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
// fatfs_cache_set_next_cluster:
|
||
|
|
//-----------------------------------------------------------------------------
|
||
|
|
int fatfs_cache_set_next_cluster(struct fatfs *fs, FL_FILE *file, uint32 clusterIdx, uint32 nextCluster)
|
||
|
|
{
|
||
|
|
#ifdef FAT_CLUSTER_CACHE_ENTRIES
|
||
|
|
uint32 slot = clusterIdx % FAT_CLUSTER_CACHE_ENTRIES;
|
||
|
|
|
||
|
|
if (file->cluster_cache_idx[slot] == clusterIdx)
|
||
|
|
file->cluster_cache_data[slot] = nextCluster;
|
||
|
|
else
|
||
|
|
{
|
||
|
|
file->cluster_cache_idx[slot] = clusterIdx;
|
||
|
|
file->cluster_cache_data[slot] = nextCluster;
|
||
|
|
}
|
||
|
|
#endif
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|