blob: e762283e67604c3848705aefd248f99c2adb9f34 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
/*-------------------------------------------------------------------------
*
* preadv.c
* Implementation of preadv(2) for platforms that lack one.
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/port/preadv.c
*
*-------------------------------------------------------------------------
*/
#include "c.h"
#include <unistd.h>
#include "port/pg_iovec.h"
ssize_t
pg_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset)
{
ssize_t sum = 0;
ssize_t part;
for (int i = 0; i < iovcnt; ++i)
{
part = pg_pread(fd, iov[i].iov_base, iov[i].iov_len, offset);
if (part < 0)
{
if (i == 0)
return -1;
else
return sum;
}
sum += part;
offset += part;
if (part < iov[i].iov_len)
return sum;
}
return sum;
}
|
