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git/compat/mmap.c
Yiannis Marangos 9aa91af036 wrapper.c: add xpread() similar to xread()
It is a common mistake to call read(2)/pread(2) and forget to
anticipate that they may return error with EAGAIN/EINTR when the
system call is interrupted.

We have xread() helper to relieve callers of read(2) from having to
worry about it; add xpread() helper to do the same for pread(2).

Update the caller in the builtin/index-pack.c and the mmap emulation
in compat/.

Signed-off-by: Yiannis Marangos <yiannis.marangos@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-10 12:18:55 -07:00

40 lines
692 B
C

#include "../git-compat-util.h"
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
size_t n = 0;
if (start != NULL || !(flags & MAP_PRIVATE))
die("Invalid usage of mmap when built with NO_MMAP");
start = xmalloc(length);
if (start == NULL) {
errno = ENOMEM;
return MAP_FAILED;
}
while (n < length) {
ssize_t count = xpread(fd, (char *)start + n, length - n, offset + n);
if (count == 0) {
memset((char *)start+n, 0, length-n);
break;
}
if (count < 0) {
free(start);
errno = EACCES;
return MAP_FAILED;
}
n += count;
}
return start;
}
int git_munmap(void *start, size_t length)
{
free(start);
return 0;
}