void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
- HANDLE hmap;
+ HANDLE osfhandle, hmap;
void *temp;
- off_t len;
- struct stat st;
+ LARGE_INTEGER len;
uint64_t o = offset;
uint32_t l = o & 0xFFFFFFFF;
uint32_t h = (o >> 32) & 0xFFFFFFFF;
- if (!fstat(fd, &st))
- len = st.st_size;
- else
+ osfhandle = (HANDLE)_get_osfhandle(fd);
+ if (!GetFileSizeEx(osfhandle, &len))
die("mmap: could not determine filesize");
- if ((length + offset) > len)
- length = xsize_t(len - offset);
+ if ((length + offset) > len.QuadPart)
+ length = xsize_t(len.QuadPart - offset);
if (!(flags & MAP_PRIVATE))
die("Invalid usage of mmap when built with USE_WIN32_MMAP");
- hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL,
- PAGE_WRITECOPY, 0, 0, NULL);
+ hmap = CreateFileMapping(osfhandle, NULL,
+ prot == PROT_READ ? PAGE_READONLY : PAGE_WRITECOPY, 0, 0, NULL);
if (!hmap) {
errno = EINVAL;
return MAP_FAILED;
}
- temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
+ temp = MapViewOfFileEx(hmap, prot == PROT_READ ?
+ FILE_MAP_READ : FILE_MAP_COPY, h, l, length, start);
if (!CloseHandle(hmap))
warning("unable to close file mapping handle");