?? ff.c
字號:
/* Read File */
/*-----------------------------------------------------------------------*/
FRESULT f_read (
FIL *fp, /* Pointer to the file object */
void *buff, /* Pointer to data buffer */
UINT btr, /* Number of bytes to read */
UINT *br /* Pointer to number of bytes read */
)
{
FRESULT res;
DWORD clst, sect, remain;
UINT rcnt, cc;
BYTE *rbuff = buff;
*br = 0;
res = validate(fp->fs, fp->id); /* Check validity of the object */
if (res != FR_OK) LEAVE_FF(fp->fs, res);
if (fp->flag & FA__ERROR) /* Check abort flag */
LEAVE_FF(fp->fs, FR_INT_ERR);
if (!(fp->flag & FA_READ)) /* Check access mode */
LEAVE_FF(fp->fs, FR_DENIED);
remain = fp->fsize - fp->fptr;
if (btr > remain) btr = (UINT)remain; /* Truncate btr by remaining bytes */
for ( ; btr; /* Repeat until all data transferred */
rbuff += rcnt, fp->fptr += rcnt, *br += rcnt, btr -= rcnt) {
if ((fp->fptr % SS(fp->fs)) == 0) { /* On the sector boundary? */
if (fp->csect >= fp->fs->csize) { /* On the cluster boundary? */
clst = (fp->fptr == 0) ? /* On the top of the file? */
fp->org_clust : get_cluster(fp->fs, fp->curr_clust);
if (clst <= 1) ABORT(fp->fs, FR_INT_ERR);
if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
fp->curr_clust = clst; /* Update current cluster */
fp->csect = 0; /* Reset sector offset in the cluster */
}
sect = clust2sect(fp->fs, fp->curr_clust); /* Get current sector */
if (!sect) ABORT(fp->fs, FR_INT_ERR);
sect += fp->csect;
cc = btr / SS(fp->fs); /* When remaining bytes >= sector size, */
if (cc) { /* Read maximum contiguous sectors directly */
if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
cc = fp->fs->csize - fp->csect;
if (disk_read(fp->fs->drive, rbuff, sect, (BYTE)cc) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
fp->csect += (BYTE)cc; /* Next sector address in the cluster */
rcnt = SS(fp->fs) * cc; /* Number of bytes transferred */
continue;
}
#if !_FS_TINY
#if !_FS_READONLY
if (fp->flag & FA__DIRTY) { /* Write sector I/O buffer if needed */
if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
fp->flag &= (BYTE)~FA__DIRTY;
}
#endif
if (fp->dsect != sect) { /* Fill sector buffer with file data */
if (disk_read(fp->fs->drive, fp->buf, sect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
}
#endif
fp->dsect = sect;
fp->csect++; /* Next sector address in the cluster */
}
rcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs)); /* Get partial sector data from sector buffer */
if (rcnt > btr) rcnt = btr;
#if _FS_TINY
if (move_window(fp->fs, fp->dsect)) /* Move sector window */
ABORT(fp->fs, FR_DISK_ERR);
MemCpy(rbuff, &fp->fs->win[fp->fptr % SS(fp->fs)], rcnt); /* Pick partial sector */
#else
MemCpy(rbuff, &fp->buf[fp->fptr % SS(fp->fs)], rcnt); /* Pick partial sector */
#endif
}
LEAVE_FF(fp->fs, FR_OK);
}
#if !_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Write File */
/*-----------------------------------------------------------------------*/
FRESULT f_write (
FIL *fp, /* Pointer to the file object */
const void *buff, /* Pointer to the data to be written */
UINT btw, /* Number of bytes to write */
UINT *bw /* Pointer to number of bytes written */
)
{
FRESULT res;
DWORD clst, sect;
UINT wcnt, cc;
const BYTE *wbuff = buff;
*bw = 0;
res = validate(fp->fs, fp->id); /* Check validity of the object */
if (res != FR_OK) LEAVE_FF(fp->fs, res);
if (fp->flag & FA__ERROR) /* Check abort flag */
LEAVE_FF(fp->fs, FR_INT_ERR);
if (!(fp->flag & FA_WRITE)) /* Check access mode */
LEAVE_FF(fp->fs, FR_DENIED);
if (fp->fsize + btw < fp->fsize) btw = 0; /* File size cannot reach 4GB */
for ( ; btw; /* Repeat until all data transferred */
wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt) {
if ((fp->fptr % SS(fp->fs)) == 0) { /* On the sector boundary? */
if (fp->csect >= fp->fs->csize) { /* On the cluster boundary? */
if (fp->fptr == 0) { /* On the top of the file? */
clst = fp->org_clust; /* Follow from the origin */
if (clst == 0) /* When there is no cluster chain, */
fp->org_clust = clst = create_chain(fp->fs, 0); /* Create a new cluster chain */
} else { /* Middle or end of the file */
clst = create_chain(fp->fs, fp->curr_clust); /* Follow or streach cluster chain */
}
if (clst == 0) break; /* Could not allocate a new cluster (disk full) */
if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
fp->curr_clust = clst; /* Update current cluster */
fp->csect = 0; /* Reset sector address in the cluster */
}
#if _FS_TINY
if (fp->fs->winsect == fp->dsect && move_window(fp->fs, 0)) /* Write back data buffer prior to following direct transfer */
ABORT(fp->fs, FR_DISK_ERR);
#else
if (fp->flag & FA__DIRTY) { /* Write back data buffer prior to following direct transfer */
if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
fp->flag &= (BYTE)~FA__DIRTY;
}
#endif
sect = clust2sect(fp->fs, fp->curr_clust); /* Get current sector */
if (!sect) ABORT(fp->fs, FR_INT_ERR);
sect += fp->csect;
cc = btw / SS(fp->fs); /* When remaining bytes >= sector size, */
if (cc) { /* Write maximum contiguous sectors directly */
if (fp->csect + cc > fp->fs->csize) /* Clip at cluster boundary */
cc = fp->fs->csize - fp->csect;
if (disk_write(fp->fs->drive, wbuff, sect, (BYTE)cc) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
fp->csect += (BYTE)cc; /* Next sector address in the cluster */
wcnt = SS(fp->fs) * cc; /* Number of bytes transferred */
continue;
}
#if _FS_TINY
if (fp->fptr >= fp->fsize) { /* Avoid silly buffer filling at growing edge */
if (move_window(fp->fs, 0)) ABORT(fp->fs, FR_DISK_ERR);
fp->fs->winsect = sect;
}
#else
if (fp->dsect != sect) { /* Fill sector buffer with file data */
if (fp->fptr < fp->fsize &&
disk_read(fp->fs->drive, fp->buf, sect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
}
#endif
fp->dsect = sect;
fp->csect++; /* Next sector address in the cluster */
}
wcnt = SS(fp->fs) - (fp->fptr % SS(fp->fs)); /* Put partial sector into file I/O buffer */
if (wcnt > btw) wcnt = btw;
#if _FS_TINY
if (move_window(fp->fs, fp->dsect)) /* Move sector window */
ABORT(fp->fs, FR_DISK_ERR);
MemCpy(&fp->fs->win[fp->fptr % SS(fp->fs)], wbuff, wcnt); /* Fit partial sector */
fp->fs->wflag = 1;
#else
MemCpy(&fp->buf[fp->fptr % SS(fp->fs)], wbuff, wcnt); /* Fit partial sector */
fp->flag |= FA__DIRTY;
#endif
}
if (fp->fptr > fp->fsize) fp->fsize = fp->fptr; /* Update file size if needed */
fp->flag |= FA__WRITTEN; /* Set file changed flag */
LEAVE_FF(fp->fs, FR_OK);
}
/*-----------------------------------------------------------------------*/
/* Synchronize the File Object */
/*-----------------------------------------------------------------------*/
FRESULT f_sync (
FIL *fp /* Pointer to the file object */
)
{
FRESULT res;
DWORD tim;
BYTE *dir;
res = validate(fp->fs, fp->id); /* Check validity of the object */
if (res == FR_OK) {
if (fp->flag & FA__WRITTEN) { /* Has the file been written? */
#if !_FS_TINY /* Write-back dirty buffer */
if (fp->flag & FA__DIRTY) {
if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
LEAVE_FF(fp->fs, FR_DISK_ERR);
fp->flag &= (BYTE)~FA__DIRTY;
}
#endif
/* Update the directory entry */
res = move_window(fp->fs, fp->dir_sect);
if (res == FR_OK) {
dir = fp->dir_ptr;
dir[DIR_Attr] |= AM_ARC; /* Set archive bit */
ST_DWORD(dir+DIR_FileSize, fp->fsize); /* Update file size */
ST_WORD(dir+DIR_FstClusLO, fp->org_clust); /* Update start cluster */
ST_WORD(dir+DIR_FstClusHI, fp->org_clust >> 16);
tim = get_fattime(); /* Updated time */
ST_DWORD(dir+DIR_WrtTime, tim);
fp->flag &= (BYTE)~FA__WRITTEN;
fp->fs->wflag = 1;
res = sync(fp->fs);
}
}
}
LEAVE_FF(fp->fs, res);
}
#endif /* !_FS_READONLY */
/*-----------------------------------------------------------------------*/
/* Close File */
/*-----------------------------------------------------------------------*/
FRESULT f_close (
FIL *fp /* Pointer to the file object to be closed */
)
{
FRESULT res;
#if _FS_READONLY
res = validate(fp->fs, fp->id);
if (res == FR_OK) fp->fs = NULL;
LEAVE_FF(fp->fs, res);
#else
res = f_sync(fp);
if (res == FR_OK) fp->fs = NULL;
return res;
#endif
}
#if _FS_MINIMIZE <= 2
/*-----------------------------------------------------------------------*/
/* Seek File R/W Pointer */
/*-----------------------------------------------------------------------*/
FRESULT f_lseek (
FIL *fp, /* Pointer to the file object */
DWORD ofs /* File pointer from top of file */
)
{
FRESULT res;
DWORD clst, bcs, nsect, ifptr;
res = validate(fp->fs, fp->id); /* Check validity of the object */
if (res != FR_OK) LEAVE_FF(fp->fs, res);
if (fp->flag & FA__ERROR) /* Check abort flag */
LEAVE_FF(fp->fs, FR_INT_ERR);
if (ofs > fp->fsize /* In read-only mode, clip offset with the file size */
#if !_FS_READONLY
&& !(fp->flag & FA_WRITE)
#endif
) ofs = fp->fsize;
ifptr = fp->fptr;
fp->fptr = 0; fp->csect = 255;
nsect = 0;
if (ofs > 0) {
bcs = (DWORD)fp->fs->csize * SS(fp->fs); /* Cluster size (byte) */
if (ifptr > 0 &&
(ofs - 1) / bcs >= (ifptr - 1) / bcs) { /* When seek to same or following cluster, */
fp->fptr = (ifptr - 1) & ~(bcs - 1); /* start from the current cluster */
ofs -= fp->fptr;
clst = fp->curr_clust;
} else { /* When seek to back cluster, */
clst = fp->org_clust; /* start from the first cluster */
#if !_FS_READONLY
if (clst == 0) { /* If no cluster chain, create a new chain */
clst = create_chain(fp->fs, 0);
if (clst == 1) ABORT(fp->fs, FR_INT_ERR);
if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
fp->org_clust = clst;
}
#endif
fp->curr_clust = clst;
}
if (clst != 0) {
while (ofs > bcs) { /* Cluster following loop */
#if !_FS_READONLY
if (fp->flag & FA_WRITE) { /* Check if in write mode or not */
clst = create_chain(fp->fs, clst); /* Force streached if in write mode */
if (clst == 0) { /* When disk gets full, clip file size */
ofs = bcs; break;
}
} else
#endif
clst = get_cluster(fp->fs, clst); /* Follow cluster chain if not in write mode */
if (clst == 0xFFFFFFFF) ABORT(fp->fs, FR_DISK_ERR);
if (clst <= 1 || clst >= fp->fs->max_clust) ABORT(fp->fs, FR_INT_ERR);
fp->curr_clust = clst;
fp->fptr += bcs;
ofs -= bcs;
}
fp->fptr += ofs;
fp->csect = (BYTE)(ofs / SS(fp->fs)); /* Sector offset in the cluster */
if (ofs % SS(fp->fs)) {
nsect = clust2sect(fp->fs, clst); /* Current sector */
if (!nsect) ABORT(fp->fs, FR_INT_ERR);
nsect += fp->csect;
fp->csect++;
}
}
}
if (nsect && nsect != fp->dsect && fp->fptr % SS(fp->fs)) {
#if !_FS_TINY
#if !_FS_READONLY
if (fp->flag & FA__DIRTY) { /* Write-back dirty buffer if needed */
if (disk_write(fp->fs->drive, fp->buf, fp->dsect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
fp->flag &= (BYTE)~FA__DIRTY;
}
#endif
if (disk_read(fp->fs->drive, fp->buf, nsect, 1) != RES_OK)
ABORT(fp->fs, FR_DISK_ERR);
#endif
fp->dsect = nsect;
}
#if !_FS_READONLY
if (fp->fptr > fp->fsize) { /* Set changed flag if the file size is extended */
fp->fsize = fp->fptr;
fp->flag |= FA__WRITTEN;
}
#endif
LEAVE_FF(fp->fs, res);
}
#if _FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Create a Directroy Object */
/*-----------------------------------------------------------------------*/
FRESULT f_opendir (
DIR *dj, /* Pointer to directory object to create */
const char *path /* Pointer to the directory path */
)
{
FRESULT res;
NAMEBUF(sfn, lfn);
BYTE *dir;
res = auto_mount(&path, &dj->fs, 0);
if (res == FR_OK) {
INITBUF((*dj), sfn, lfn);
res = follow_path(dj, path); /* Follow the path to the directory */
if (res == FR_OK) { /* Follow completed */
dir = dj->dir;
if (dir) { /* It is not the root dir */
if (dir[DIR_Attr] & AM_DIR) { /* The object is a directory */
dj->sclust = ((DWORD)LD_WORD(dir+DIR_FstClusHI) << 16) | LD_WORD(dir+DIR_FstClusLO);
} else { /* The object is not a directory */
res = FR_NO_PATH;
}
} else { /* It is the root dir */
dj->sclust = (dj->fs->fs_type == FS_FAT32) ? dj->fs->dirbase : 0;
}
if (res == FR_OK) res = dir_seek(dj, 0);
dj->id = dj->fs->id;
} else {
if (res == FR_NO_FILE) res = FR_NO_PATH;
}
}
LEAVE_FF(dj->fs, res);
}
/*-----------------------------------------------------------------------*/
/*
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