//-----------------------------------------------------------------------------
// fl_fclose: Close an open file
//-----------------------------------------------------------------------------
void fl_fclose(void *f)
{
FL_FILE *file = (FL_FILE *)f;
// If first call to library, initialise
CHECK_FL_INIT();
if (file)
{
FL_LOCK(&_fs);
// Flush un-written data to file
fl_fflush(f);
// File size changed?
if (file->filelength_changed)
{
#ifdef FATFS_INC_WRITE_SUPPORT
// Update filesize in directory
fatfs_update_file_length(&_fs, file->parentcluster, (char*)file->shortfilename, file->filelength);
#endif
file->filelength_changed = 0;
}
file->bytenum = 0;
file->filelength = 0;
file->startcluster = 0;
file->file_data.address = 0xFFFFFFFF;
file->file_data.dirty = 0;
file->filelength_changed = 0;
// Free file handle
_free_file(file);
fatfs_fat_purge(&_fs);
FL_UNLOCK(&_fs);
}
}
int32_t file_flush(file_handle_t handle)
{
return fl_fflush(handle);
}
int fl_fwrite(const void * data, int size, int count, void *f )
{
FL_FILE *file = (FL_FILE *)f;
unsigned long sector;
unsigned long offset;
unsigned long length = (size*count);
unsigned char *buffer = (unsigned char *)data;
// int dirtySector = 0;
unsigned long bytesWritten = 0;
unsigned long copyCount;
// If first call to library, initialise
CHECK_FL_INIT();
if (!file)
return -1;
FL_LOCK(&_fs);
// No write permissions
if (!(file->flags & FILE_WRITE))
{
FL_UNLOCK(&_fs);
return -1;
}
// Append writes to end of file
if (file->flags & FILE_APPEND)
file->bytenum = file->filelength;
// Else write to current position
// Calculate start sector
sector = file->bytenum / FAT_SECTOR_SIZE;
// Offset to start copying data from first sector
offset = file->bytenum % FAT_SECTOR_SIZE;
while (bytesWritten < length)
{
// We have upto one sector to copy
copyCount = FAT_SECTOR_SIZE - offset;
// Only require some of this sector?
if (copyCount > (length - bytesWritten))
copyCount = (length - bytesWritten);
// Do we need to read a new sector?
if (file->file_data.address != sector)
{
// Flush un-written data to file
if (file->file_data.dirty)
fl_fflush(file);
// If we plan to overwrite the whole sector, we don't need to read it first!
if (copyCount != FAT_SECTOR_SIZE)
{
// NOTE: This does not have succeed; if last sector of file
// reached, no valid data will be read in, but write will
// allocate some more space for new data.
// Get LBA of sector offset within file
if (!_read_sector(file, sector))
memset(file->file_data.sector, 0x00, FAT_SECTOR_SIZE);
}
file->file_data.address = sector;
file->file_data.dirty = 0;
}
// Copy from application buffer into sector buffer
memcpy((unsigned char*)(file->file_data.sector + offset), (unsigned char*)(buffer + bytesWritten), copyCount);
// Mark buffer as dirty
file->file_data.dirty = 1;
// Increase total read count
bytesWritten += copyCount;
// Increment file pointer
file->bytenum += copyCount;
// Move onto next sector and reset copy offset
sector++;
offset = 0;
}
// Write increased extent of the file?
if (file->bytenum > file->filelength)
{
// Increase file size to new point
file->filelength = file->bytenum;
// We are changing the file length and this
// will need to be writen back at some point
file->filelength_changed = 1;
}
FL_UNLOCK(&_fs);
return (size*count);
}
//-----------------------------------------------------------------------------
// fl_fread: Read a block of data from the file
//-----------------------------------------------------------------------------
int fl_fread(void * buffer, int size, int length, void *f )
{
unsigned long sector;
unsigned long offset;
int copyCount;
int count = size * length;
int bytesRead = 0;
FL_FILE *file = (FL_FILE *)f;
// If first call to library, initialise
CHECK_FL_INIT();
if (buffer==NULL || file==NULL)
return -1;
// No read permissions
if (!(file->flags & FILE_READ))
return -1;
// Nothing to be done
if (!count)
return 0;
// Check if read starts past end of file
if (file->bytenum >= file->filelength)
return -1;
// Limit to file size
if ( (file->bytenum + count) > file->filelength )
count = file->filelength - file->bytenum;
// Calculate start sector
sector = file->bytenum / FAT_SECTOR_SIZE;
// Offset to start copying data from first sector
offset = file->bytenum % FAT_SECTOR_SIZE;
while (bytesRead < count)
{
// Do we need to re-read the sector?
if (file->file_data.address != sector)
{
// Flush un-written data to file
if (file->file_data.dirty)
fl_fflush(file);
// Get LBA of sector offset within file
if (!_read_sector(file, sector))
// Read failed - out of range (probably)
break;
file->file_data.address = sector;
file->file_data.dirty = 0;
}
// We have upto one sector to copy
copyCount = FAT_SECTOR_SIZE - offset;
// Only require some of this sector?
if (copyCount > (count - bytesRead))
copyCount = (count - bytesRead);
// Copy to application buffer
memcpy( (unsigned char*)((unsigned char*)buffer + bytesRead), (unsigned char*)(file->file_data.sector + offset), copyCount);
// Increase total read count
bytesRead += copyCount;
// Increment file pointer
file->bytenum += copyCount;
// Move onto next sector and reset copy offset
sector++;
offset = 0;
}
return bytesRead;
}
