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92 lines
3.5 KiB
C
92 lines
3.5 KiB
C
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//-----------------------------------------------------------------------------
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//-----------------------------------------------------------------------------
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// FAT16/32 File IO Library
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// V2.6
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// Ultra-Embedded.com
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// Copyright 2003 - 2012
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//
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// Email: admin@ultra-embedded.com
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//
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// License: GPL
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// If you would like a version with a more permissive license for use in
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// closed source commercial applications please contact me for details.
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//-----------------------------------------------------------------------------
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//
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// This file is part of FAT File IO Library.
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//
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// FAT File IO Library is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// FAT File IO Library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with FAT File IO Library; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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//-----------------------------------------------------------------------------
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//-----------------------------------------------------------------------------
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#include <string.h>
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#include "fat_cache.h"
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// Per file cluster chain caching used to improve performance.
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// This does not have to be enabled for architectures with low
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// memory space.
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//-----------------------------------------------------------------------------
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// fatfs_cache_init:
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//-----------------------------------------------------------------------------
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int fatfs_cache_init(struct fatfs *fs, FL_FILE *file)
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{
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#ifdef FAT_CLUSTER_CACHE_ENTRIES
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int i;
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for (i=0;i<FAT_CLUSTER_CACHE_ENTRIES;i++)
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{
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file->cluster_cache_idx[i] = 0xFFFFFFFF; // Not used
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file->cluster_cache_data[i] = 0;
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}
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#endif
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return 1;
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}
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//-----------------------------------------------------------------------------
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// fatfs_cache_get_next_cluster:
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//-----------------------------------------------------------------------------
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int fatfs_cache_get_next_cluster(struct fatfs *fs, FL_FILE *file, uint32 clusterIdx, uint32 *pNextCluster)
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{
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#ifdef FAT_CLUSTER_CACHE_ENTRIES
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uint32 slot = clusterIdx % FAT_CLUSTER_CACHE_ENTRIES;
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if (file->cluster_cache_idx[slot] == clusterIdx)
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{
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*pNextCluster = file->cluster_cache_data[slot];
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return 1;
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}
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#endif
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return 0;
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}
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//-----------------------------------------------------------------------------
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// fatfs_cache_set_next_cluster:
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//-----------------------------------------------------------------------------
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int fatfs_cache_set_next_cluster(struct fatfs *fs, FL_FILE *file, uint32 clusterIdx, uint32 nextCluster)
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{
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#ifdef FAT_CLUSTER_CACHE_ENTRIES
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uint32 slot = clusterIdx % FAT_CLUSTER_CACHE_ENTRIES;
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if (file->cluster_cache_idx[slot] == clusterIdx)
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file->cluster_cache_data[slot] = nextCluster;
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else
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{
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file->cluster_cache_idx[slot] = clusterIdx;
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file->cluster_cache_data[slot] = nextCluster;
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}
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#endif
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return 1;
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}
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