1 /* Copyright 1996,1997,1999,2001,2002,2009 Alain Knaff.
2 * This file is part of mtools.
3 *
4 * Mtools is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * Mtools is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with Mtools. If not, see <http://www.gnu.org/licenses/>.
16 *
17 * Force I/O to be done to complete transfer length
18 *
19 * written by:
20 *
21 * Alain L. Knaff
22 * alain@knaff.lu
23 *
24 */
25
26 #include "sysincludes.h"
27 #include "msdos.h"
28 #include "stream.h"
29
force_io(Stream_t * Stream,char * buf,mt_off_t start,size_t len,int (* io)(Stream_t *,char *,mt_off_t,size_t))30 static int force_io(Stream_t *Stream,
31 char *buf, mt_off_t start, size_t len,
32 int (*io)(Stream_t *, char *, mt_off_t, size_t))
33 {
34 int ret;
35 int done=0;
36
37 while(len){
38 ret = io(Stream, buf, start, len);
39 if ( ret <= 0 ){
40 if (done)
41 return done;
42 else
43 return ret;
44 }
45 start += ret;
46 done += ret;
47 len -= ret;
48 buf += ret;
49 }
50 return done;
51 }
52
force_write(Stream_t * Stream,char * buf,mt_off_t start,size_t len)53 int force_write(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
54 {
55 return force_io(Stream, buf, start, len,
56 Stream->Class->write);
57 }
58
force_read(Stream_t * Stream,char * buf,mt_off_t start,size_t len)59 int force_read(Stream_t *Stream, char *buf, mt_off_t start, size_t len)
60 {
61 return force_io(Stream, buf, start, len,
62 Stream->Class->read);
63 }
64