git/compat/win32mmap.c

47 строки
1.1 KiB
C
Исходник Обычный вид История

#include "../git-compat-util.h"
void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
HANDLE osfhandle, hmap;
void *temp;
LARGE_INTEGER len;
uint64_t o = offset;
uint32_t l = o & 0xFFFFFFFF;
uint32_t h = (o >> 32) & 0xFFFFFFFF;
osfhandle = (HANDLE)_get_osfhandle(fd);
if (!GetFileSizeEx(osfhandle, &len))
die("mmap: could not determine filesize");
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(osfhandle, NULL,
prot == PROT_READ ? PAGE_READONLY : PAGE_WRITECOPY, 0, 0, NULL);
if (!hmap) {
errno = EINVAL;
return MAP_FAILED;
}
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");
if (temp)
return temp;
errno = GetLastError() == ERROR_COMMITMENT_LIMIT ? EFBIG : EINVAL;
return MAP_FAILED;
}
int git_munmap(void *start, size_t length)
{
return !UnmapViewOfFile(start);
}