git-commit-vandalism/compat/win32mmap.c

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#include "../git-compat-util.h"
/*
* Note that this doesn't return the actual pagesize, but
* the allocation granularity. If future Windows specific git code
* needs the real getpagesize function, we need to find another solution.
*/
int mingw_getpagesize(void)
{
SYSTEM_INFO si;
GetSystemInfo(&si);
return si.dwAllocationGranularity;
}
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
HANDLE hmap;
void *temp;
size_t len;
struct stat st;
uint64_t o = offset;
uint32_t l = o & 0xFFFFFFFF;
uint32_t h = (o >> 32) & 0xFFFFFFFF;
if (!fstat(fd, &st))
len = xsize_t(st.st_size);
else
die("mmap: could not determine filesize");
if ((length + offset) > len)
length = len - offset;
if (!(flags & MAP_PRIVATE))
die("Invalid usage of mmap when built with USE_WIN32_MMAP");
hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
0, 0, 0);
if (!hmap)
return MAP_FAILED;
temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
if (!CloseHandle(hmap))
warning("unable to close file mapping handle\n");
return temp ? temp : MAP_FAILED;
}
int git_munmap(void *start, size_t length)
{
return !UnmapViewOfFile(start);
}