compat/bswap.h: fix endianness detection
[git/git.git] / compat / mmap.c
1 #include "../git-compat-util.h"
2
3 void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
4 {
5 size_t n = 0;
6
7 if (start != NULL || !(flags & MAP_PRIVATE))
8 die("Invalid usage of mmap when built with NO_MMAP");
9
10 start = xmalloc(length);
11 if (start == NULL) {
12 errno = ENOMEM;
13 return MAP_FAILED;
14 }
15
16 while (n < length) {
17 ssize_t count = pread(fd, (char *)start + n, length - n, offset + n);
18
19 if (count == 0) {
20 memset((char *)start+n, 0, length-n);
21 break;
22 }
23
24 if (count < 0) {
25 if (errno == EAGAIN || errno == EINTR)
26 continue;
27 free(start);
28 errno = EACCES;
29 return MAP_FAILED;
30 }
31
32 n += count;
33 }
34
35 return start;
36 }
37
38 int git_munmap(void *start, size_t length)
39 {
40 free(start);
41 return 0;
42 }