2 * This file is part of DisOrder
3 * Copyright (C) 2010 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /** @file lib/hreader.c
19 * @brief Hands-off reader - read files without keeping them open
26 void hreader_init(const char *path
, struct hreader
*h
) {
27 memset(h
, 0, sizeof *h
);
28 h
->path
= xstrdup(path
);
30 h
->buffer
= xmalloc_noptr(h
->bufsize
);
33 int hreader_read(struct hreader
*h
, void *buffer
, size_t n
) {
34 if(h
->consumed
== h
->bytes
) {
37 if((r
= hreader_fill(h
)) <= 0)
40 if(n
> h
->bytes
- h
->consumed
)
41 n
= h
->bytes
- h
->consumed
;
42 memcpy(buffer
, h
->buffer
+ h
->consumed
, n
);
47 int hreader_fill(struct hreader
*h
) {
48 if(h
->consumed
< h
->bytes
)
49 return h
->bytes
- h
->consumed
;
50 h
->bytes
= h
->consumed
= 0;
51 int fd
= open(h
->path
, O_RDONLY
);
54 if(lseek(fd
, h
->offset
, SEEK_SET
) < 0) {
58 int n
= read(fd
, h
->buffer
, h
->bufsize
);
67 void hreader_consume(struct hreader
*h
, size_t n
) {