[thirdparty/git.git] / compat / win32mmap.c

#include "../git-compat-util.h"

void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
	HANDLE hmap;
	void *temp;
	off_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 = st.st_size;
	else
		die("mmap: could not determine filesize");

	if ((length + offset) > len)
		length = xsize_t(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);
}
Commit	Line	Data
b130a72b JL	1	#include "../git-compat-util.h"
b130a72b JL	2
b130a72b JL	3	void git_mmap(void start, size_t length, int prot, int flags, int fd, off_t offset)
	4	{
	5	HANDLE hmap;
	6	void *temp;
60890cc6	7	off_t len;
b130a72b JL	8	struct stat st;
	9	uint64_t o = offset;
	10	uint32_t l = o & 0xFFFFFFFF;
	11	uint32_t h = (o >> 32) & 0xFFFFFFFF;
	12
	13	if (!fstat(fd, &st))
60890cc6	14	len = st.st_size;
b130a72b JL	15	else
	16	die("mmap: could not determine filesize");
	17
	18	if ((length + offset) > len)
60890cc6	19	length = xsize_t(len - offset);
b130a72b JL	20
	21	if (!(flags & MAP_PRIVATE))
	22	die("Invalid usage of mmap when built with USE_WIN32_MMAP");
	23
	24	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
	25	0, 0, 0);
	26
	27	if (!hmap)
	28	return MAP_FAILED;
	29
	30	temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
	31
	32	if (!CloseHandle(hmap))
	33	warning("unable to close file mapping handle\n");
	34
	35	return temp ? temp : MAP_FAILED;
	36	}
	37
	38	int git_munmap(void *start, size_t length)
	39	{
	40	return !UnmapViewOfFile(start);
	41	}